# Pre-existing underground Wire gong to detached garage



## tk3000 (Oct 29, 2015)

Hello, 

I have a detached garage relatively far from the main circuit breaker the the point of entrance of power to the house. The wires are buried, it seems to be alumminum wires, and I would guess the gauge would something like 4 or 5 (nothing written on cable sheathing, and marks).

I understand that there is no need to a ground wire travelling from the main to the subpanel due to the fact that the neutral line is already grounded; but in these situation I would imagine that there should be a ground rod next to the garage building itself, and I was wondering whether or not this would be required? (currently there is no ground rod visible and no ground wire per se going to the subpanel in the garage). 

I am not sure whether or not the whole the underground cable is travelling inside conduit (I guess it depends on the depth of the burial, etc), but at the end points the wires do exit the ground from a pvc conduit. At the garage there is a pvc conduit exit the ground and going all the way to a hole in the concrete wall (so the wires are not exposed), but near the house the point that the wires exit the ground is not protected by conduit (no sure if that is ok by code) as shown below (please ignore all mess of wires  they have been removed already  and only look into the pvc conduit protruding from the ground):






In the interior of the garage I am installing a new subpanel, as shown below:


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## JoeD (Oct 29, 2015)

Previous installs are grandfathered and did not require a ground wire. Current installs do require a ground wire. The old three wire feed required a ground rod at the garage.

Since this appears to be a new install a ground wire is required. At the very least the conductors I see coming into the bottom new panel must be in conduit. Individual conductors like those pictured must be in conduit all the way.


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## kok328 (Oct 29, 2015)

Looks like you will have to install a bar for ground in the panel box. On a sub-panel, the grown bar and neutral bar must be separate


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## tk3000 (Oct 30, 2015)

JoeD said:


> Previous installs are grandfathered and did not require a ground wire. Current installs do require a ground wire. The old three wire feed required a ground rod at the garage.
> 
> Since this appears to be a new install a ground wire is required. At the very least the conductors I see coming into the bottom new panel must be in conduit. Individual conductors like those pictured must be in conduit all the way.



So, I would need a separate ground rod for the garage (I assume one ground rod will suffice, not needing two). The copper #6 bare ground wire would likely take a different path to get inside the garage and it would not need to be in a conduit? 

Yeah, it is a new circuit breaker panel and there will be new wires (and since it is a garage and more prone to have rodent) it will all be in a conduit (bx or emt). 

I hope there is no need of a conduit inside the concrete walls because the wire enters the wall inside a conduit from the ground and then inside the walls it travels up to the spot whereon the subpanel is. Would a small  flexible conduit from the point the cable exit the wall to the subpanel suffice? 

thanks!


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## tk3000 (Oct 30, 2015)

kok328 said:


> Looks like you will have to install a bar for ground in the panel box. On a sub-panel, the grown bar and neutral bar must be separate



Yep, I know that. It still is a working in progress. thks!


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## hornetd (Oct 30, 2015)

kok328 said:


> Looks like you will have to install a bar for ground in the panel box. On a sub-panel, the grown bar and neutral bar must be separate



This is a repair and replacement of the wiring in the detached structure.  The Feeder is grandfathered so a separate Equipment Grounding Conductor (EGC) in the feeder is not required.  

What is required is a Grounding Electrode System which does meet all of the requirements for an service equipment installation.  That means that you will have to measure; perhaps under observation by the  AHJs inspector; the impedance of the first ground rod to assure that it is less than Twenty Five Ohms; OR you can just drive a second ground rod and call it done.  

Since the existing Feeder installation must be wired as if it were a utility supplied service there will be no immediate need for a separate EGC Buss Bar in the Garage's panel.  That said it would do no harm to install one to make the installation ready for any future change in it's supply conductors.  One thing to be aware of if you do install a separate EGC buss bar is that as long as the feeder is only three conductors both the EGC buss bar and the Neutral buss bar must be bonded to the Neutral conductor of the feeder at the Building Disconnecting Means; in your case the garage's panel.  

The National Institute of Standards and Technology (NIST) has done extensive research on electrical grounding and has published a best practices guide for installation of Grounding Electrode Systems at buildings that do not have any of the more effective Grounding Electrodes present at the structure already.  Were there is no Underground Metal Water Piping, Ground Ring, or Concrete Encased Electrode; best practice would be to install the two Driven Rods at least the sum of their own lengths apart and to drive them through the bottom of a trench that is at least Two and one half feet deep.  You connect the rods to each other and to the Building Disconnecting Means by installing a bare copper conductor, #2 AWG or larger, in the bottom of the trench so that it's entire length, until it reaches the building, will be buried a full thirty inches deep.  If you check the code language you will find that that matches the requirements for a Ground Ring as to depth of bury, conductor size, and length.  The only thing it does not do that a Ground Ring would is to circle the entire structure.  

Since the garage's panel cabinet will function as the Building Disconnecting Means Enclosure it must have a main breaker/s; totaling no more than six breakers, or have no more space then would be enough for Six double pole breakers.  If single pole breakers are installed they must be handle tied into pairs so that it would never take more than six throws of the hand to disconnect all power from the building.  Best practice would be to have a single main breaker as the Building Disconnecting Means but the code only limits the number of main breakers to Six.  

Those are the high points.  Do let us know if you have more questions.


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## JoeD (Oct 30, 2015)

Conduit is require the full length of those wires, even inside the concrete walls.


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## Kabris (Oct 31, 2015)

Yeah Joe is right, I just noticed the individual feeder wires coming out of the concrete wall and going into the bottom of the panel. Those wires, as is, are not considered protected and need to be, even through the wall. You may be able to get an LB and reducing washers so you don't have to alter the setup, but that looks pretty tight.


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## Kabris (Oct 31, 2015)

Non armored sealtite might work there too, but it still looks tight. Good luck.


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## tk3000 (Oct 31, 2015)

hornetd said:


> This is a repair and replacement of the wiring in the detached structure.  The Feeder is grandfathered so a separate Equipment Grounding Conductor (EGC) in the feeder is not required.
> 
> What is required is a Grounding Electrode System which does meet all of the requirements for an service equipment installation.  That means that you will have to measure; perhaps under observation by the  AHJs inspector; the impedance of the first ground rod to assure that it is less than Twenty Five Ohms; OR you can just drive a second ground rod and call it done.
> 
> ...



At the location near the service entrance and near the circuit breaker panel I driven and installed two ground rods at the required depth and required distance from each other. I was wondering about the impedance though, that is a good point; and nobody talks about it.  As a matter of fact there are three ground rods near the circuit breaker panel (one is an old one that I decided to don't use unless needed).

So there is not need for an ground conductor in the garage. But then there is no harm in having a EGC (one ground rod only) near the garage building and connected to the subpanel. I have electronic sensitive equipment so I may install a EGC there. The old subpanel had a bus bar and a ground bar in spite of having no ground rod installed for the garage structure.

Hmm... The means of a main disconnect is not present at the moment; so I would need to have a main breaker or an extra disconnecting panel? And since the subpanel does not have a spot for a main breaker there is no main disconnect in the subpanel. But the subpanel is tied to the main circuit breaker panel at the house by means of a 60 amps circuit breaker, wouldn't that suffice as a main disconnect? 

I will have a 30amps charging stations located inside the garage in order to charge a EV vehicle, and the other 30amps should be more than sufficient for my tools and lights. 


Thanks for your insights!


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## tk3000 (Oct 31, 2015)

JoeD said:


> Conduit is require the full length of those wires, even inside the concrete walls.




This is the underground conduit point of entrance bringing power to the garage. 







It does not seem reasonable at all to expect someone to break through the wall to install a cable that is perfect fine and protected, and that was originally installed and passed all inspection at the time.  Anyhow, I will not invite the inspector to my garage anyway.


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## tk3000 (Oct 31, 2015)

Kabris said:


> Non armored sealtite might work there too, but it still looks tight. Good luck.



You mean liquid tight conduit? I don't believe -- and it is not reasonable -- for any inspector (most of the time they do a very superficial job and check the power outlets, ground, gfci functionality) to try to break through the wall to verify an installation that is perfect fine in all possible respects.


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## hornetd (Nov 1, 2015)

tk3000 said:


> At the location near the service entrance and near the circuit breaker panel I driven and installed two ground rods at the required depth and required distance from each other. I was wondering about the impedance though, that is a good point; and nobody talks about it.  As a matter of fact there are three ground rods near the circuit breaker panel (one is an old one that I decided to don't use unless needed).



I was not writing about the Service Equipment at your house.  I was only writing about the Garage Installation that you showed a photograph of.  Now that you have written about the service equipment though I will point out that you should bond all three ground rods together even though one of them is older and seems superfluous.  You don't want any conductive underground objects of any description left near to and yet unconnected to the Grounding Electrode System of your Service Equipment.  The differences of Potential between two underground objects can cause a voltage gradient across the surface of the ground which would be dangerous to people or animals including family pets.  One way to effectively raise the voltage across a piece of ground is to have underground conductive objects that are not bonded to each other that may cause the current flow from a lightning discharge to flow more strongly in one direction between the Grounding Electrode System; in your case your two driven rods; and an abandoned rod in its flowing out into the entire space around the strike until the discharge is dissipated.



> So there is not need for an ground conductor in the garage. But then there is no harm in having a EGC (one ground rod only) near the garage building and connected to the subpanel. I have electronic sensitive equipment so I may install a EGC there. The old subpanel had a bus bar and a ground bar in spite of having no ground rod installed for the garage structure.


The harm in having one rod only at your garage is that it would not be a code compliant installation unless the Single rod that you installed had an impedance to ground of Twenty Five Ohms or less.  I'm trying to tell you that you must wire the garage's Building Disconnecting Means the same as if it were supplied by a separate service from the electrical utility.  The only difference between the two installations is the formal name of them in the code.  That would not be true if the Feeder included an Equipment Grounding Conductor (EGC) but your garage feeder does not.  

250.32 Buildings or Structures Supplied by a Feeder(s) or Branch Circuit(s)
(A) Grounding Electrode. Building(s) or structure(s) supplied by feeder(s) or branch circuit(s) shall have a grounding electrode or grounding electrode system installed in accordance with Part III of Article 250. The grounding electrode conductor(s) shall be connected in accordance with 250.32(B) or (C). Where there is no existing grounding electrode, the grounding electrode(s) required in 250.50 shall be installed.  



> Hmm... The means of a main disconnect is not present at the moment; so I would need to have a main breaker or an extra disconnecting panel? And since the subpanel does not have a spot for a main breaker there is no main disconnect in the subpanel. But the subpanel is tied to the main circuit breaker panel at the house by means of a 60 amps circuit breaker, wouldn't that suffice as a main disconnect?


As you can see by the language in 225.32 below the Building Disconnecting Means may not be located in another building except under exceptions that never apply to dwellings.  Just like the Service Equipment and the Service Disconnecting Means at your house, your garage must have Building Disconnecting Means consisting of switches, breakers, or pullout fuse holders that can be turned off with no more than six "throws" of the hand.  The required Building Disconnecting Means must be located either outside the structure OR inside "nearest the point of entrance of the conductors."  The best remedy in your case is to buy a tie down kit made by the manufacturer of the panel that anchors a two pole breaker to the panel so that it cannot be removed without tools.  That Breaker becomes your Building Disconnecting Means when you connect the two energized (Hot) conductors of your feeder to it's terminals so as to feed current from it's terminals through it's mechanism, through the buss bar clamps on that breaker's bottom, and into the buss bars to supply the remaining breakers which are connected to the buss bars.  

225.31 Disconnecting Means
Means shall be provided for disconnecting all ungrounded conductors that supply or pass through the building or structure.

225.32 Location
The disconnecting means shall be installed either inside or outside of the building or structure served or where the conductors pass through the building or structure.  The disconnecting means shall be at a readily accessible location nearest the point of entrance of the conductors. For the purposes of this section, the requirements in 230.6 shall be utilized.

225.33 Maximum Number of Disconnects
(A) General. Th e disconnecting means for each supply permitted by 225.30 shall consist of not more than six switches or six circuit breakers mounted in a single enclosure, in a group of separate enclosures, or in or on a switchboard or switchgear.  There shall be no more than six disconnects per supply grouped in any one location.  

Exception: For the purposes of this section, disconnecting means used solely for the control circuit of the ground-fault protection system, or the control circuit of the power-operated supply disconnecting means, installed as part of the listed equipment, shall not be considered a supply disconnecting means.
(B) Single-Pole Units. Two or three single-pole switches or breakers capable of individual operation shall be permitted on multiwire circuits, one pole for each ungrounded conductor, as one multipole disconnect, provided they are equipped with identified handle ties or a master handle to disconnect all ungrounded conductors with no more than six operations of the hand.  

225.34 Grouping of Disconnects
(A) General. The two to six disconnects as permitted in 225.33 shall be grouped.  Each disconnect shall be marked to indicate the load served.  

Exception: One of the two to six disconnecting means permitted in 225.33, where used only for a water pump also intended to provide fire protection, shall be permitted to be located remote from the other disconnecting means.  



> I will have a 30amps charging stations located inside the garage in order to charge a EV vehicle, and the other 30amps should be more than sufficient for my tools and lights.
> 
> 
> Thanks for your insights!



The panel appears to be Eight slot.  Is that correct?  If it is eight slot will the remaining six slots be enough for the loads you will have in the detached garage?  The back fed main breaker is Two slots.  Your charging station is One or Two breaker slots depending on whether it is 120 or 240 volts.  Will the remaining Four or Five slots be enough for the loads you have planned?


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## hornetd (Nov 1, 2015)

tk3000 said:


> This is the underground conduit point of entrance bringing power to the garage.
> 
> 
> 
> ...


What was never acceptable, under any addition of the National Electric Code (NEC), is to have your garage's feeder cable exposed to physical damage as it is were it comes up out of the ground and enters the void spaces in your cinder block wall.  The depth of bury for cable in earth  has been Two Feet since the first edition of the NEC.  Since at least the mid Fifties of the previous century the NEC has required that the cable be protected from the bottom of the trench to the point of entry into the structure.  How I would protect it now is to buy a piece or Schedule Eighty Non Metallic Conduit in the three or four inch size.  Cut it in half lengthwise on a table saw, band saw, or with a Sawzall.  Fasten that half shell of conduit to the garage footer from the bottom of the trench to were the cable enters the cinder block void.  If, as seems likely to me, the footer is wider than the garage structure itself you will need to make miter cuts at the joint were the cable comes up over the footer and turns back to horizontal reach the wall so that the cable is continuously protected from the  bottom of the trench to were it enters the cinder block void space.  By doing that you will avoid the need to pull the cable down out of the wall so as to be able to run it through a conduit that has not been cut in half.  

All that appears wrong on the inside is that you have let the Jacket of the cable slide back into the wall.  The jacket of the cable should be clamped into a Service Entry Cable Connector which comes directly into a knockout on the back of the panel's enclosing cabinet.  Alternatively it can come into a trough or large box; either of which should be just as deep as the panel cabinet itself; and then passes into the panel through a close conduit nipple or a chase nipple.  If you are not too far along with the project just re-position the panels cabinet so that the cable connector can enter through the back wall of the enclosure.  

Let us know if other questions arise.


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## tk3000 (Nov 5, 2015)

Thanks for your thorough response. 

Interesting point about the presence of an unbonded ground rod, I never consider this dop  issue. The third ground rod should be very close to  one of the new rods that I installed by judging from how the ground wire exit the ground, but I have to dig in order to find out the whereabouts of this old third ground rod. It seems that  this old house circuit had ground added some point and it was applied to some outlets in the kitchen; this added ground circuit was obtained by one single ground rod and a clamp  to the copper pipes (I am assuming it simply because I am not sure due to the fact that low life forms thieves entered the vacant house previous to me buying it and stole lots of the copper). As of now, ground by means of copper pipes is not an option any longer given that most of the pipes have been replaced with pex.  Also, I will go ahead an install two ground rods near the garage; but the bare copper ground wire will travel a different path than the one used by the underground cable in order to enter the build; and I assume the bare ground wire does not need to be in a conduit (it whould be tucked away from the veiw and inconspicuous and so protected against mechanical damage) 

&#8220;The harm in having one rod only at your garage is that it would not be a code compliant installation unless the Single rod that you installed had an impedance to ground of Twenty Five Ohms or less. I'm trying to tell you that you must wire the garage's Building Disconnecting Means the same as if it were supplied by a separate service from the electrical utility. The only difference between the two installations is the formal name of them in the code. That would not be true if the Feeder included an Equipment Grounding Conductor (EGC) but your garage feeder does not.*
&#8220;

Does the above implies that the lack of ground would be compensated by the main disconnect (means of isolation) is a substitute for a ground circuit? And in case, I had two ground rods properly installed and bond to the subpanel there would be no need to a main disconnect? 

&#8220;
*The best remedy in your case is to buy a tie down kit made by the manufacturer of the panel that anchors a two pole breaker to the panel so that it cannot be removed without tools. That Breaker becomes your Building Disconnecting Means when you connect the two energized (Hot) conductors of your feeder to it's terminals so as to feed current from it's terminals through it's mechanism, through the buss bar clamps on that breaker's bottom, and into the buss bars to supply the remaining breakers which are connected to the buss bars.* 
&#8220;

The subpanel I installed is a SquareD rather common one (got it for about $20 or $25) and bought some breaker switches. Is the tie down kit equivalent to having a main breaker inside the panel? If that is the case a main circuit breaker panel (a 100 amps ) could be used instead of a regular small subpanel. 


&#8220;
The panel appears to be Eight slot. Is that correct? If it is eight slot will the remaining six slots be enough for the loads you will have in the detached garage? The back fed main breaker is Two slots. Your charging station is One or Two breaker slots depending on whether it is 120 or 240 volts. Will the remaining Four or Five slots be enough for the loads you have planned? &#8220;

Yeah, it is an eight slot subpanel. Is the back fed breaker equivalent to a the tie down kit you mentioned before, and does it take two slots in the subpanel? The vehicle has it own 120 Charger that can be hooked to any 15 amps 120v outlet, but I want to install quick charge stations that would require 220V 30 amps power (so it would take two slots). Most of my tools require 15amps or 20 amps, but chances are I will never be using many thing at the e same time; so 6 slots should suffice

&#8220;
What was never acceptable, under any addition of the National Electric Code (NEC), is to have your garage's feeder cable exposed to physical damage as it is were it comes up out of the ground and enters the void spaces in your cinder block wall. The depth of bury for cable in earth has been Two Feet since the first edition of the NEC. Since at least the mid Fifties of the previous century the NEC has required that the cable be protected from the bottom of the trench to the point of entry into the structure. How I would protect it now is to buy a piece or Schedule Eighty Non Metallic Conduit in the three or four inch size. Cut it in half lengthwise on a table saw, band saw, or with a Sawzall. Fasten that half shell of conduit to the garage footer from the bottom of the trencucture itself you will need to make miter cuts at the joint were the cable comes up over the footer and turns back to horizontal reach the wall so that the cable is continuously protected from the bottom of the trench to were it enters the cinder block void space. By doing that you will avoid the need to pull the cable down out of the wall so as to be able to run it through a conduit that has not been cut in half.* 
&#8220;

The underground wire comes out of the ground via a conductor. Inside the cinder block walls it would be further protecgted against any mechanical damage and the elements. Where the underground cable emerge near the house (the o the end)close to main circuit breaker  the underground cable emerge from a protruding pvc conduit and it is in fact unprotected and it is in fact a mess (but then I believe that it was the action of vandals and criminals during a time the house was vacant and I did not own it)

Above you mean cut the conduit half lengthwise so that it would like a semi-circle? At the garage end the conductors are protetected from the point where they exit the ground and then enter the wall via a pvc conduit. I believe that it is not protected inside the concrete wall (but I am not sure, at least it does not come up inside the garage with any sheathing or conduit otherwise). The garage was built in the 80s, and did no bring the underground cable to the garage or anything; I am simply rewiring (new wires, conduits, outlets, lights, etc). the interior of the garage and replaced the subpanel with a new one.

tk3000


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## hornetd (Nov 7, 2015)

tk3000 said:


> Thanks for your thorough response.
> 
> Interesting point about the presence of an unbonded ground rod, I never consider this dop  issue. The third ground rod should be very close to  one of the new rods that I installed by judging from how the ground wire exit the ground, but I have to dig in order to find out the whereabouts of this old third ground rod. It seems that  this old house circuit had ground added some point and it was applied to some outlets in the kitchen; this added ground circuit was obtained by one single ground rod and a clamp  to the copper pipes (I am assuming it simply because I am not sure due to the fact that low life forms thieves entered the vacant house previous to me buying it and stole lots of the copper). As of now, ground by means of copper pipes is not an option any longer given that most of the pipes have been replaced with pex.  Also, I will go ahead an install two ground rods near the garage; but the bare copper ground wire will travel a different path than the one used by the underground cable in order to enter the build; and I assume the bare ground wire does not need to be in a conduit (it would be tucked away from the veiw and inconspicuous and so protected against mechanical damage)


If the Equipment Grounding Conductor (EGC) is not jacketed with Armor or enclosed in raceway you have to increase it's size to Number Four American Wire Gauge (4 AWG).



> The harm in having one rod only at your garage is that it would not be a code compliant installation unless the Single rod that you installed had an impedance to ground of Twenty Five Ohms or less. I'm trying to tell you that you must wire the garage's Building Disconnecting Means the same as if it were supplied by a separate service from the electrical utility. The only difference between the two installations is the formal name of them in the code. That would not be true if the Feeder included an Equipment Grounding Conductor (EGC) but your garage feeder does not.*
> 
> 
> Does the above imply that the lack of ground would be compensated by the main disconnect (means of isolation) is a substitute for a ground circuit? And in case, I had two ground rods properly installed and bond to the subpanel there would be no need to a main disconnect?


No it does not imply that.  Both a Building Disconnecting Means and a Grounding Electrode System are required at each separate structure in all cases



> 
> *The best remedy in your case is to buy a tie down kit made by the manufacturer of the panel that anchors a two pole breaker to the panel so that it cannot be removed without tools. That Breaker becomes your Building Disconnecting Means when you connect the two energized (Hot) conductors of your feeder to it's terminals so as to feed current from it's terminals through it's mechanism, through the buss bar clamps on that breaker's bottom, and into the buss bars to supply the remaining breakers which are connected to the buss bars.*
> 
> 
> The subpanel I installed is a SquareD rather common one (got it for about $20 or $25) and bought some breaker switches. Is the tie down kit equivalent to having a main breaker inside the panel? If that is the case a main circuit breaker panel (a 100 amps ) could be used instead of a regular small subpanel.


Yes the tie down kit is equivalent to having a main breaker.  The breaker that you will tie down using that kit becomes the main breaker.  Yes you could use a main circuit breaker panel but since you already have the Main Lug Only (MLO) panel the tie down kit is your best remedy at this point.  Find the Square D part number inside the panel cabinet and take that to any Square D Stocking Distributor.  They can provide you with the correct kit to tie down the Two Pole circuit breaker which will serve as your Building Disconnecting Means (ie main breaker).  In that way you will not have to go the hassle of returning the MLO panel that you already have.  



> 
> The panel appears to be Eight slot. Is that correct? If it is eight slot will the remaining six slots be enough for the loads you will have in the detached garage? The back fed main breaker is Two slots. Your charging station is One or Two breaker slots depending on whether it is 120 or 240 volts. Will the remaining Four or Five slots be enough for the loads you have planned? 
> 
> Yeah, it is an eight slot subpanel. Is the back fed breaker equivalent to a the tie down kit you mentioned before, and does it take two slots in the subpanel? The vehicle has it own 120 Charger that can be hooked to any 15 amps 120v outlet, but I want to install quick charge stations that would require 220V 30 amps power (so it would take two slots). Most of my tools require 15amps or 20 amps, but chances are I will never be using many thing at the e same time; so 6 slots should suffice.


The back fed breaker is the one that you will fasten in place by installing the tie down kit so that it can serve as the Building Disconnecting Means (Main Breaker).  Since the feeder includes two energized conductors that have to be opened by the Building Disconnecting Means the back fed breaker will be two pole.  



> 
> What was never acceptable, under any addition of the National Electric Code (NEC), is to have your garage's feeder cable exposed to physical damage as it is were it comes up out of the ground and enters the void spaces in your cinder block wall. The depth of bury for cable in earth has been Two Feet since the first edition of the NEC. Since at least the mid Fifties of the previous century the NEC has required that the cable be protected from the bottom of the trench to the point of entry into the structure. How I would protect it now is to buy a piece or Schedule Eighty Non Metallic Conduit in the three or four inch size. Cut it in half lengthwise on a table saw, band saw, or with a Sawzall. Fasten that half shell of conduit to the garage footer from the bottom of the trencucture itself you will need to make miter cuts at the joint were the cable comes up over the footer and turns back to horizontal reach the wall so that the cable is continuously protected from the bottom of the trench to were it enters the cinder block void space. By doing that you will avoid the need to pull the cable down out of the wall so as to be able to run it through a conduit that has not been cut in half.*
> 
> 
> ...


I think that you may be mistaking the the Poly(vinyl chloride) (PVC) jacket of the Type USE cable for PVC Conduit.  Both are made from Poly(vinyl chloride) but the cable jacket is much thinner and uses the flexible formulation of that plastic.  Non Metallic Conduit (NMC) is often made from PVC but it is of a much thicker cross section and uses the rigid formulation of that plastic.  

From the photograph that you posted the Feeder conductors appear to be in Type USE (Underground Service Entry) Cable.  Cable of any type requires protection from physical damage from the bottom of the Two foot deep trench to eight feet above finished grade.  The bottom line is that the cable that is showing in the photograph is required to be protected from the bottom of the trench until it enters the structure.  Once the cable enters the building it is no longer required to have physical protection unless it remains exposed to physical damage.  If that cable were installed on, instead of in, the interior wall of the garage it would be exposed to Extreme Physical Damage by the movement of Motor Vehicles.  That may be why the original installer ran it inside the cavities in the block wall.  

Again what I would do is to cover the cable from the bottom of the trench until it enters the wall with material having the same resistance to physical damage as Non Metallic Conduit.  I would obtain that material by cutting through a length of Schedule Eighty Rigid Nonmetallic Conduit lengthwise.   I would then relocate the panel's cabinet so that the indoor conductors enter through the back wall of the cabinet.  I would install a chase nipple through the hole in the cabinet's back wall with an insulating plastic bushing on the end of it's threads inside the cinder block so as to protect the insulation on the feeder conductors from the rough edges of both holes through the cinder block and the wall of the cabinet.


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## tk3000 (Nov 11, 2015)

"If the Equipment Grounding Conductor (EGC) is not jacketed with Armor or enclosed in raceway you have to increase it's size to Number Four American Wire Gauge (4 AWG)." 

=> Yeah, I intend to use 4 AWG bare copper for the ground rods and will install two 10 ft copper 5/8 rods near the point wherein the underground cable emerge.

These tie down kits does not seem something one can find in any home center store. Is it also called "breaker retaining kit", like the following: 

http://www.gordonelectricsupply.com...pFhoRa8OoncZRGY8Jr1jG1L2OWRYhDUf-zRoC7ePw_wcB

"The underground wire comes out of the ground via a conductor." Sorry, this was a typo. I actually meant that it come out of the ground via a conduit. A PVC conduit.  The underground cable consist of three wires without any outer sheathing, and it indeed comes out of the ground via a rigid grey pvc conduit; so doesn't that mean that the cable is protected until it enters the structured and also mechanically protected while travelling inside the concrete wall, and thus the only a small section is exposed once it protrudes from the wall to then enter the circuit breaker panel? Do I need to protect this small section of exposed wires?

thanks!


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## nealtw (Nov 11, 2015)

The cable under the box does look like a convenient place to hang the trouble light. Whether it is code not, I would put a conduit over it.


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## hornetd (Nov 12, 2015)

tk3000 said:


> "If the Equipment Grounding Conductor (EGC) is not jacketed with Armor or enclosed in raceway you have to increase it's size to Number Four American Wire Gauge (4 AWG)."
> 
> => Yeah, I intend to use 4 AWG bare copper for the ground rods and will install two 10 ft copper 5/8 rods near the point wherein the underground cable emerge.
> 
> ...


The item in the link that you included is the one you would need if your panel were a Square D QO type.  Since it is instead Square D Homeline make sure you get the retaining kit for a Homeline two pole breaker.  They are different!  QO breakers use 3/4" slots for each single pole breaker and thus 1&1/2" for a two pole breaker.  Homeline breakers use one inch for each single pole breaker and two inches for a double pole.  Why the retaining kit is required is that without it a breaker can be removed from the buss bar in the panel and yet still be energized.  If the breaker were to be closed when it was removed the exposed buss bar grips on the bottom of the breaker would then remain energized while accessible to human contact.  The retaining kit can only be removed with tools so that removing it from the buss bar cannot be done by anything except a quite deliberate act.

In answer to your question YES, you do have to protect those feeder conductors anywhere that they are exposed to physical damage.  As a practical answer all you need to do is protect the feeder conductors were they come out of the wall cavity.  I would probably use a four inch by four inch by four inch deep box placed so that it can be nippled to the panel enclosure and cut a hole through it's back to install the largest chase nipple that would fit through the hole into the cinder block wall cavity.  Only careful measurement on site will confirm that a 4X4 inch box will both cover the hole in the block wall and still line up with the bottom of the panel so as to permit the installation of the nipple between the box and the panel.  If the panel cover that you have is the flush mount type that overhangs the box by a half inch or more on all sides then make sure you will end up with enough room for the cover between the 4X4 box and the bottom of the panel.  Fit an insulating bushing to the end of that  chase nipple that goes into the wall so as to protect the conductor insulation from abrasion on the nipple itself.


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## nealtw (Nov 12, 2015)

Or lower the panel so the cables could come thru a gromet in one of those back knock outs??????????


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## hornetd (Nov 13, 2015)

nealtw said:


> Or lower the panel so the cables could come thru a gromet in one of those back knock outs??????????


I had already suggested that possibility to him bit I also noticed that the panel cabinet shown in one of his photographs is already piped with EMT.  That does make moving it a little challenging when compared with connecting a box that would serve as a protective cover via a nipple to the panel's enclosure.


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## bud16415 (Nov 13, 2015)

Just so I understand correctly it is to code to run individual wires as shown thru a block wall or thru the cores in the blocks and the only points it has to be contained in conduit is where it is exposed to the room?


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## tk3000 (Nov 13, 2015)

nealtw said:


> Or lower the panel so the cables could come thru a gromet in one of those back knock outs??????????



yeah, that is a possibility too not to be forgotten. But I would have to drill new holes on the concrete, bore a hole on the plywood where the panel seats, etc. If I can not align a small box with a nipple I will take that route!


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## tk3000 (Nov 13, 2015)

bud16415 said:


> Just so I understand correctly it is to code to run individual wires as shown thru a block wall or thru the cores in the blocks and the only points it has to be contained in conduit is where it is exposed to the room?



I am not the one who install the cable through the walls or brought the cable to the garage. If it was me I would further investigate before doing anything. The garage was built in the 80s and that's probably when they did the electrical hook up. But if horneted believes it is ok, so it shall be ok.


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## nealtw (Nov 13, 2015)

I missed the earlier suggestion, but I always want to look at all possible routes. You could also make the hole lower so you could fit conduit with an elbo, maybe.


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## nealtw (Nov 13, 2015)

We see unfused cable hidden in concrete all the time, when the meter is in the garage or living room and breaker panel is in the basement. So I suspect this woulkd be fine.


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## bud16415 (Nov 13, 2015)

tk3000 said:


> I am not the one who install the cable through the walls or brought the cable to the garage. If it was me I would further investigate before doing anything. The garage was built in the 80s and that's probably when they did the electrical hook up. But if horneted believes it is ok, so it shall be ok.



I wasnt suggesting it was wrong and I do believe all input Horneted and the other pros give is always to code. I also know that a lot of people read the forums that never post and these records stand for many years and pop up in search engines regularly. I too would have enclosed the whole run and given your situation I would do the box as suggested or maybe a LB could be used to turn the corner. I was kind of wondering if this is a case that its grandfathered in or is this an ok approved practice and could be done in new construction. 

Im still not clear how the wires get up the wall to that point or do they just come straight thru the block wall?


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## JoeD (Nov 13, 2015)

Cable would be fine. This is not a cable. This is individual conductors. Where I live they would not be permitted to be in the block as pictured. They should have come all the way through the block in conduit.


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## nealtw (Nov 13, 2015)

JoeD said:


> Cable would be fine. This is not a cable. This is individual conductors. Where I live they would not be permitted to be in the block as pictured. They should have come all the way through the block in conduit.



So would you pull the Conductors thru the bottom of the wall and run a conduit up to the box?


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## JoeD (Nov 14, 2015)

I would pull the conductors through a complete conduit from the house the the garage, through the wall an LB and up into the box..


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## tk3000 (Nov 15, 2015)

JoeD said:


> I would pull the conductors through a complete conduit from the house the the garage, through the wall an LB and up into the box..



Besides some extra abrasion resistance I don't see how the simple outer sheathing of a cable (such as the case of romex) offer much in terms of protection especially for conductors that a inside a concrete wall.

Anyhow, the underground cable coming from the house is inside rigid pvc conduit, and while it enters the garage wall from the bottom it is inside rigid pvc conduit. I am not sure whether or not it travel inside the wall inside pvc conduit or not, but I assume it does not: I will put an inspection camera to check inside. All in all, I can not see imagine breaking through the concrete wall simply to add a conduit inside a wall that offers far more protection than any conduit. Maybe a liquid tight conduit partially inside the wall...


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## hornetd (Nov 16, 2015)

nealtw said:


> So would you pull the Conductors thru the bottom of the wall and run a conduit up to the box?



When I was being trained in electrical work I became a fanatic for code compliance because I kept seeing such sloppy work being done on so many jobs.  Now that I have been in the craft over fifty years I have mellowed.  That does not mean I have gotten careless or even casual with compliance but it does mean that I am willing to be practical about existing installations.  

"90.1 Purpose
(A) Practical Safeguarding. The purpose of this Code is the practical safeguarding of persons and property from hazards arising from the use of electricity."  

Installing the right kind of conduit inside the garage would certainly be code compliant but I think it falls short of best practice.  Conduit inside a garage is exposed to what the code calls "extreme physical damage" That is because motor vehicles might strike the conduit in the course of being parked in the garage.  To address that concern you would cover the conduit with flanged V metal guards, install schedule Eighty NMC,  or use rigid metallic conduit.  It is better practice to run the cable or conduit either outside the structure or within the block wall.  

Since the conductors in question are a feeder circuit that is protected by a circuit breaker against short circuit and overcurrent they come under the requirements of either 
"ARTICLE 338
Service-Entrance Cable:
Types SE and USE"  
or 
"ARTICLE 340
Underground Feeder and Branch-Circuit Cable: Type UF"  

Since the language of both articles is essentially the same in this regard I have quoted from "Article 340 Underground Feeder and Branch-Circuit Cable: Type UF"  

"340.10 Uses Permitted
Type UF cable shall be permitted as follows:
(4) Installation Methods for Branch Circuits and Feeders.
(a) Interior Installations. In addition to the provisions of
this article, Type SE service-entrance cable used for interior
wiring shall comply with the installation requirements of Part II
of Article 334, excluding 334.80.

II. Installation
334.10 Uses Permitted
(A) Type NM. Type NM cable shall be permitted as follows:
(2) To be installed or fished in air voids in masonry block or tile walls

The fly in the ointment is, 
"340.10 Uses Permitted
Type UF cable shall be permitted as follows:
(2) As single-conductor cables. Where installed as single conductor cables, all conductors of the feeder grounded conductor or branch circuit, including the grounded conductor and equipment grounding conductor, if any, shall be installed in accordance with 300.3.

300.3 Conductors
(A) Single Conductors. Single conductors specified in Table 310.104(A) shall only be installed where part of a recognized wiring method of Chapter 3."

Both Type SE & UF appear in that table.  The  upshot of all that is that the individual conductors should have been run in a complete raceway from the bottom of the trench to the point were it enters the cabinet of the Building Disconnecting Means.  What seems to have gone wrong here is that the conduit stops at the bottom of the cavity in the cinder block wall.  Since the individual conductors are laboratory listed to be used as cables when used underground the mistake is that they were pulled into the cinder block wall without further protection.  I suspect that was an oversight on the inspectors part when the garage was built.  Now that they are inside the cinder block masonry units I would not go to the trouble to pull them out and build an exterior conduit extension up to the back of the panel.  When masonry is specifically formed and inspected or listed for use as a raceway; such as Cellular Concrete Floor Raceways; then the conductors are pulled into the cells in the concrete the same as any other raceway.  Although the cavities in walls built of cinder block masonry units are not listed as raceways I was treating them as equivalent in this case.  That said I will readily admit that the installation of the individual SE, USE, or UF conductor cables inside the cavities of the cinder block masonry units is not fully code compliant.  What I am hanging my hat on in this case is the basic purpose, as written into the code itself, of code compliance.  Again that is "the practical safeguarding of persons and property from hazards arising from the use of electricity."  

Others may disagree with that approach and take the position I would have taken when I was fairly new to the craft.  Some would say that the only correct way to do this is to pull the conductors out of the wall and build a raceway from the bottom of the trench to the wall of the panel cabinet.  I would not do that nor would I demand that of others when looking at the new work that does not include that feeder run.  That said I have been wrong before and I will be wrong again.


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## nealtw (Nov 16, 2015)

Tom; I was just asking Joe to finish what he started as it was clear what he was suggesting.
If you keep answering questons with such detail we will all be ready to write the test in no time.


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## tk3000 (Nov 19, 2015)

Hello Folks, 

So, once everything was said and done; I went ahead and install a pvc 4x4x4 right below the subpanel and it did fit like a glove, did not need to use any nipple or any piece of conduit: only needed a male adapter, nut, and  fitting, as shown below: 












Which brings me to the next end of the underground feed wire for the garage. The other end which then emerges next to the house (close to the circuit breaker panel, socket meter, etc) protrudes from the ground as the following: 






I was wondering if it would be ok fo the pvc conduit to be protruding from the soil and hanging out in thin air without any support, and if could simply add more pvc conduit and fittings all the way to the  nearby circuit breaker panel.

thks


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## nealtw (Nov 19, 2015)

That looks worse than anything you had in the garage. I think it should come up right next to the house. I would be asking if there was a safe way to cut the conduit and extend it to the building and then to the breaker box.


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## tk3000 (Nov 19, 2015)

nealtw said:


> That looks worse than anything you had in the garage. I think it should come up right next to the house. I would be asking if there was a safe way to cut the conduit and extend it to the building and then to the breaker box.



Yeah, I realize that it does not seem proper or acceptable; but you never know: I have seen lots of funky stuff and exceptions and grandfathered things in code. Anyhow, that is how I found it. Also, it seems that there were some sort of concrete walkway near the house which may have made it more difficult to bring the conduit near the house. It certainly does not seem proper


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## nealtw (Nov 19, 2015)

If that is metal conduit you should be able to dig up the first connector and change it.


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## Kabris (Nov 20, 2015)

No that's PVC. I would extend the underground to the house. PVC floating that far from the house is going to be flimsy and prone to damage. I'd also be curious to dig around that area to see if that PVC isn't just sleeved into the ground, because that conduit looks awfully small to pull the wire into.  If it is a full run of PVC, then whoever installed it either fitted the wire into the PVC as they layed it, or they used a ton of lube.  To extend to the house I would use a rolling pipe cutter and carefully cut the PVC without damaging the wires, and then extend it to the house. When penetrating into the house once the conduit is coming up flush against it, you can use a 4x4 box (like you used in the garage), or an LB to 90 into the house.


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## hornetd (Nov 20, 2015)

tk3000 said:


> Hello Folks,
> 
> ...Which brings me to the next end of the underground feed wire for the garage. The other end which then emerges next to the house (close to the circuit breaker panel, socket meter, etc) protrudes from the ground as the following:
> 
> ...



The reason that the conduit coming out of the ground is not next to the house wall is that the foundation footer of the ground floor wall extends out from the wall a foot or so.  




At this point, because of the conduits susceptibility to physical damage, I would carefully dig down to the bottom of the trench were that conduit probably begins and rebuild that conduit so that it came over the top of the footer and ran up to the wall.  Use a pair of forty five degree elbows to run the conduit down to the bottom of the trench from the top of the footer and then you will still have 180 Degrees of bends to get it to an L or a box.


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## tk3000 (Nov 21, 2015)

Kabris said:


> No that's PVC. I would extend the underground to the house. PVC floating that far from the house is going to be flimsy and prone to damage. I'd also be curious to dig around that area to see if that PVC isn't just sleeved into the ground, because that conduit looks awfully small to pull the wire into.  If it is a full run of PVC, then whoever installed it either fitted the wire into the PVC as they layed it, or they used a ton of lube.  To extend to the house I would use a rolling pipe cutter and carefully cut the PVC without damaging the wires, and then extend it to the house. When penetrating into the house once the conduit is coming up flush against it, you can use a 4x4 box (like you  an LB to used in the garage), or90 into the house.



That is a good point, I also had the impression that the conduit (1/2") has a way too small internal diameter to accommodate the wires: tried to slip the e wires through a piece of 1/2 conduit and was really  tough. I will dig deeper and take a closer look soon. But it seems that in some situations it is acceptable to bury conductors without a conduit depending on the depth of the burial, in any case these wires lack an outer sheathing so I am sure if they can be used in direct burial (have to check), but based on the on the following "When used as Type USE-2, conductor is suitable for use as underground service entrance cable for direct burial at conductor temperatures not to exceed 90°" it may be ok.

I have most of the materials and supplies to get this job done, and have done this type of work with pvc pipes mainly with plumbing; so have the tooling, glues/primers,etc. But I will have to increase the size of the conduit to 3/4 for sure.  

thk


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## tk3000 (Nov 21, 2015)

hornetd said:


> The reason that the conduit coming out of the ground is not next to the house wall is that the foundation footer of the ground floor wall extends out from the wall a foot or so.
> 
> 
> 
> ...



Yeah, the building foot should be the main reason for the clearance. But, also there are some remnants of an old concrete sidewalk besides the exterior walls right next to the walls (probably from decades ago and now there are plants growing on it, etc). 

Will carefully dig and cut the top of the existing pvc conduit, and build a new pvc conduit track underground which will then emerge again next to the exterior wall whereby the circuit breaker panel is located on the other side. The two 45 degrees will create a smooth curve radius (good way of approaching it)

I will post back with the commencement of the job.


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## hornetd (Nov 23, 2015)

tk3000 said:


> Yeah, the building foot should be the main reason for the clearance. But, also there are some remnants of an old concrete sidewalk besides the exterior walls right next to the walls (probably from decades ago and now there are plants growing on it, etc).
> 
> Will carefully dig and cut the top of the existing pvc conduit, and build a new pvc conduit track underground which will then emerge again next to the exterior wall whereby the circuit breaker panel is located on the other side. The two 45 degrees will create a smooth curve radius (good way of approaching it)
> 
> I will post back with the commencement of the job.


You only have to put enough conduit between the two Forty Five degree bends to make the one elbow sit in the bottom of the trench; two feet below finished grade to the top of the conductors; and the other elbow come level with the top of the footer, or other obstruction, so as to line up with the Ninety that will turn the conduit up the wall to were you terminate it.


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## tk3000 (Dec 4, 2015)

"You only have to put enough conduit between the two Forty Five degree bends to make the one elbow sit in the bottom of the trench; two feet below finished grade to the top of the conductors; and the other elbow come level with the top of the footer, or other obstruction, so as to line up with the Ninety that will turn the conduit up the wall to were you terminate it. "


This underground wiring inside a ½ conduit protruding next to the house scenario is more complicated that what it looks. I did some digging and inspected it closer, and it seems that it is not only the footing but the fact that the allseason room (which houses the circuit breaker panel) addition to the house to which the underground and #4 ground copper wire converge too has some type of concrete edge near its bottom, but this concrete edge has been subject to lots of erosion throughout the years so it is not very visible. The area marked with a square is all part of the concrete bottom edge:






Another pic below showcase some small repairs I made on this concrete bottom edge at the front of the allseason addition room. The concrete  side at the corner  whereon the underground wire comes up is eroded and covered with dirty so it is not visible at first, so unless I break the concrete edge there is not way the conduit would protrude right up next to the exterior wall. And that would also explain why the conduit did not protrude right next to the exterior wall. 






After my quick inspection it seems that the whole wire is buried inside a conduit, and it is in fact 1/2 pvc conduit (I would assume that they inserted the cable inside the conduit  prior to laying the conduit+wire in the trench.

Would having the conduit protruding not quite next to the exterior wall against code now or in the past? 

thanks


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## nealtw (Dec 4, 2015)

Could you have brought it up beside the other conduit on the stucco wall?


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## nealtw (Dec 4, 2015)

BTW The concrete isn't corroded away, they just dug a trench and pored concrete in it and plumbers jack hammer thru our footing all the time, as long as they don't go thru a magor bearing point nobody finds a problem with that.
So I think you could rent one of those gas powered demo saws and cut a slot to get to the building.


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## tk3000 (Dec 11, 2015)

nealtw said:


> Could you have brought it up beside the other conduit on the stucco wall?
> 
> BTW The concrete isn't corroded away, they just dug a trench and pored concrete in it and plumbers jack hammer thru our footing all the time, as long as they don't go thru a magor bearing point nobody finds a problem with that.
> So I think you could rent one of those gas powered demo saws and cut a slot to get to the building.



Yeah, I am aiming upon at bringing it close tot he stucco, and from there it would be straight to the wood siding in the allseason room where the panel seats.

Good to know that the concrete is not eroded. But the thing smear the appearance of the exterior and is disform. To make matters worse there were lots of dirty accumulating  inside its cavities with weed growing there, and whenever it would rain the water would splash the dirty on the siding. So I'd rather fill it with concrete and try to get a smooth surface. Next year I hope to get the whole thing done.

thks!


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