# Strengthen floor for aquariums



## theboomboomcars

I am in the process of buying a new home and want to get a 360 gallon aquarium. The Home is a 1 level on a crawl space. In addition to this aquarium we will have a 120 gallon, an 80 gallon, and a 10 gallon. We will use a 55 gallon sump with the 360. I would guess that with water, stands, rocks, etc. total weight for the aquariums would be about 7000 lbs.

I have not had a chance to get below the house too see the joists and such. I am not familiar with how the whole flooring works, though I have learned quite a bit over the last week of researching, so I don't know what to look for exactly when I do get to take a look, I am hoping that I can check it out this weekend.

I am looking for any advice on what to check while I am below the house, and then what would be some good options to reinforce the floor to hold the weight. I am planning on putting all the tanks in the same room, except maybe the 10 gallon, so I will only have to worry about reinforcing the floors for the one room.

Thank you for any help.


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## guyod

Hopefully you have a high crawl space. Because your going to have to be digging some footers.

The highest my span calculator goes to is 100 psf.  (pounds per square foot) so if you think your tanks will weigh 7000 lbs then 100psf would  a 7X10 area.

using 100psf with 2x8 floor joists your max span is 8'6  
2X10 will be 10'4 

this is the distance between your main beams

Im thinking your closer to 150 psf. 

My guess would put you at 6' and 8' 

If your tanks are in one area you can probably get away with one more support beam directly under the tanks.  Double up on 2X12 for your main beam. I like to sandwich  plywood in between to help limit deflection.


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## CraigFL

guyod said:


> Hopefully you have a high crawl space. Because your going to have to be digging some footers.
> 
> The highest my span calculator goes to is 100 psf.  (pounds per square foot) so if you think your tanks will weigh 7000 lbs then 100psf would  a 7X10 area.
> 
> using 100psf with 2x8 floor joists your max span is 8'6
> 2X10 will be 10'4
> 
> this is the distance between your main beams
> 
> Im thinking your closer to 150 psf.
> 
> My guess would put you at 6' and 8'
> 
> If your tanks are in one area you can probably get away with one more support beam directly under the tanks.  Double up on 2X12 for your main beam. I like to sandwich  plywood in between to help limit deflection.



You touched on this but my vote would be to install support columns to footers under the tanks since the load is fairly concentrated. How the columns connect to the floor joists would depend on how much room you have. If you have the room, a 8" or 10" steel beam running perpendicular to the joists supported by these column would be best.


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## Adk

Well, first see what you have under your crawl space. Then think.
8.8 x 360 = 3168 lbs of water. + about 360 of gravel. + stand. If the stand is 200 lbs you still are a far cry from 7000. Your at 3728 lbs.
So take this into consideration when reinforcing the floor. You may not have to do much but you won't know until you get under to see what the construction of the floor is. "Much" is a relative term...............

JFI: I used to design and install high end reefs as well as just a few, big, almost totally sustainable fresh waters systems. This was a few years ago so I may be a bit rusty but I still remember a lot. 

Now your tank. It's length is important to how the weight is distributed.
Is the tank custom made? Is it 4' long, 6' long or is it 8'?
Is your sump going to be under tank or in another room/ closet? your sump could be 40' away if need be. The water doesn't care where it flows from.
Let me leave this for now. Get back to us.

I like your idea...a BIG tank is so much easier to maintain.


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## theboomboomcars

Thanks for the responses, they have been very helpful.

What should I use for support columns? 4x4s, 6x6s, something else?

Adk- I will be adding the 360 to an existing 120 and 80.  I think 7000lbs may be a bit high, but better to over shoot than under.  I am planning on having the sump under the tank.  The tank will be 8x3x2.

The 120 is a 4x2x2 and the 80 is 4'x18"x22" (LxWxH).

Any other tips or suggestions would be appreciated.


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## guyod

With out seeing your crawl space we cant tell you exactly what to do. 

For support columns it depends on how much height you have.  

Steel Screw jacks are the easiest thing to use. they are 2 steel poles that fit into each other. there is holes in them and you use a steel bolt through the holes to achieve your correct height then there is a big bolt up top that you screw up to get nice a snug against your beam.  i think they start at 3 feet 

    if you need less than 3 feet then use cinder blocks to build up to your correct height. use 2 blocks side by side and alternate the seam with each coarse. you can get away with using just one chimey block put you should choke the hole up. when you get to the top you can use half blocks or bricks to get as close as you can. to be done right it should all be mortared in place. to get the main beam snug against the floor joists you can use scrap boards and shims i like to use cedar shingles because of there extra width. 

i like to sit the ends on the block foundation. you will have to chip out the block to do that. 

I dont see why you have to go the whole width of the house. You can probably get away with having your beam only about 2 feet longer than the fish room.  if the beam is under 20 feet 3 supporting points should be fine.


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## guyod

Footers should be 3 feet deep to get below the frost level but since this under your house and should not freeze at all and since this just extra support. 18'' to 24'' should be fine depending on the hardness of the ground. it should be 2 feet wide.


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## guyod

I was bored and did some calculations based on craigs weight and your dimensions. 

Tank----Water weight---Extras--Total---SF---pfs
360------3168----------560-----3728---24---155
120------1056----------175-----1231---8----153
80 -------704----------100------804----6----134 
TOTALS------------------------5765 lb--38sf              

 As you can see all the tanks have very high PSF.  So because of weight distribution they all weigh very close.  A floor is normally build to only hold 40 to 50 PSF.  

As far as craig's suggestion of columns connected directly to 1 or 2 floor joists. well I don't think he realized the tanks would span so many joists. I don't see it working. 

When you look under the house inspect the floor joists for termite and dry rot very closely. .  hit the joists with a hammer and listen.. A sharp loud noise is good, a thud is not.. crawl spaces have a tendency to have high humidity leading to dry rot. under normal conditions these floor joists may still have a long life but not with lbs on them.


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## theboomboomcars

guyod, thanks for all the info, that will be very useful.

I went out to check the crawl space this afternoon, and there isn't a way in.  I am unsure what the best way to make a way in, any tips on how to go about doing this.

Thanks for the help.


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## guyod

assuming there is a couple feet of exposed cinderblock walk the entire perimater of the house looking for any place that the cinder block is replaced another material. most of the time its a painted plywood.  It may even be under a porch.  the openning may of been sided over. 
Every once in a while they are inside. which probably means its been covered up with flooring.. but check all the closet floors, utility room. i had to cut a whole in the floor once to get in. hope fully it doesnt come to that but do not buy the house if you can't get in there first.  
I noticed you from utah and im pretty sure its dry there so that means you have less of a chance of dry rot.  
how old is the house?


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## theboomboomcars

The house was built in 1890, with an addition put on in the '60s.  The area in question is the addition.  The seller has just put in new flooring and such, but also said that he was not aware of an entry way into the crawl space.  I checked the closets and around the house and did not see anything.

It is pretty dry here, and dry rot is not a common problem, termites are really rare as well.

I am pretty sure I will have to cut my way in, any recommendations on how to do it?

Thank you for your help.


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## glennjanie

Welcome to TBBCs:
For my money, I would dig down to undisturbed earth to place a 2' wide X 8" thick footer and lay 8" concrete blocks around the peremiter of the room. If it is an interior room there is no fear of getting below the frost line. The foundation would support the walls around the room on half of it and a concrete floor on the inner half; with thoroughly compacted rock or sand filling the foundation to the bottom of the concrete. I would also run a #4 reinforcing bar each foot in both directions and suspend it in the center of the 4" height of concrete.
Now you have a commercial floor and you can load it any way you please.
Please let us know how you come out.
Glenn


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## guyod

Is there a basement to the original house? did you check in there?

If its from the 60's the subfloor is probably 1" X 3" tongue and groove. .  so using a circular saw set the depth to 1 1/4 " cut the floor following a groove.  cut only an inch once the saw deck hits the floor. then look to see that the blade went all the way through. if not set it a little deeper. Keep cutting short distances and keep looking for the floor joist. once you find it take a square and make a line directly over the middle of the stud 2 feet long. Flip the saw around and find your Floor joist on the other side and do the same thing. Once you cut the hole you can nail or screw a board to the back of the tongue and groove boards now you have a cover for your hole. 
You probably will only have a 14" wide hole to crawl through


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## theboomboomcars

glennjanie- Thank you for the input.  I am having a hard time visualizing what you are describing.  Please correct any misinterpretations that I have.  
I should dig the loose dirt around the perimeter of the room where I want to put the tanks and put a concrete footer in the trench I dug out.  Then I put in concrete blocks to build a wall on top of the footer that I put in.  After this I get lost.  Do I replace the wood floors with a concrete one?  Then fill in under the concrete floor with sand or crushed rock?  Thank you for you help.

guyod- The original house does not have a basement, and I couldn't find a crawl space entrance in that part of the house either.
I am not sure what a groove in the floor would be, is it the joint between two of the wood slats, or something different?

Thank you.


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## guyod

Yup, if it is tongue and groove subflooring then there will be a groove at each joint (tongue and groove joint).  

I got confussed with glennns suggestion too . But he did say that your footer doesnt have to be that deep which is good for you. I didnt want to be the one to say that. but you do want to dig til you get to some real compact dirt. beacause any compression of the ground will sag your floor. if you are able to get screw poles under new beam then can worrry a little less about that cause you can easily screw it back up as long as your notice it.

i think he is saying to pour a concrete slab to the top of the floor joist. That would be ideal but would cost thousands and would require taking up the subfloor of the room.


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## ToolGuy

I'm wondering why not just put precast footings and screw jacks where the aquarium is going to be? It's not like he's going to be moving it around all the time. If the footprint of the aquarium is 2' x 8', and if it will sit perpendicular to the joists, that is 6 joists that need extra support. I'm assuming the aquarium sits on a base that is not on feet, so the weight is evenly spread out under it.

If it runs paralell to the joists, then only 2 or 3 will need extra support. Maybe do the same for the 120 gallon aquarium just to be on the safe side. The 80 gal. should be fine. Lot's of people have 80 gallon aquariums and they don't reinforce their floors. 

As for access, cut a sqare hole in the floor in a closet and make a cover for it.


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## glennjanie

Ok, you have the foundation built up to the bottom of the floor joists under the walls. Now, remove the wood floor for the whole aquarium room, fill the foundation with sand or compacted stone, put a 6mil polyethelyne vapor barrier down, support the #4 reinforcing bars (they make steel chairs for this) one each foot in each direction (use tie wire on each intersection of the bars), place 4" of concrete for the floor making it level with the other floors, or leave 1/2" low for space to install quarry tile.
With this floor you can place any size aquarium anywhere you want it without fear of the floor sagging or falling through.
Glenn


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## glennjanie

OH! I would also put a drain in the center of the floor and pitch the floor 1" lower from each corner to the drain.
Glenn


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## guyod

precast footings might work if he has  solid ground, 

I dont see how you can support 8 or 9 floor joist without a beam.


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## guyod

That a great idea glenn but thats not a diy job. and sounds about a $10K job.


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## ToolGuy

guyod said:


> precast footings might work if he has  solid ground,
> 
> I dont see how you can support 8 or 9 floor joist without a beam.



With 8 or 9 footings and jacks/posts/whatever works. It's not like they cost a lot. 

Rather than starting with the most costly, most complex solution, why not start with the simplest and tweek as needed. If the ground is not solid it has to be dug down to solid soil. But that's the case with any of the above mentioned solutions. If digging below the frost line is needed, again that applies to all the above. If gravel is needed for drainage under the footings... I think we all get the idea. Start with the simplest solution, then elaborate as needed. I'm guessing some footings and posts under the stress zone is all that's needed. Materials, about $100 or so. Labor, free. Simplicity, priceless.


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## theboomboomcars

Wow, take a day away from the computer and all kinds of stuff goes on.  Thanks for all the input guys.

I think we'll be shooting for the footings with support posts.  The question I have about these is are the jacks a good long term solution?  

Another question is how do I know if the floors are tongue and groove or not?  I may have to get pictures of the floor to show you to see where the grooves are and such, but I won't really be able to do that for a week or so.

When I was thinking about what to do to support the floor I was thinking along the lines of what guyod and ToolGuy were describing, which makes me feel I am not totally out of my league with this.  Though now I know what to do If I wanted to put a 10,000 gallon tank in. 

There are no closets on the new part of the house, just a living room (which is where we want to put the tanks) and a kitchen with a small wall between them, there is a small, about 10' wide, dining area that connects the living and kithen areas (this area also has the wood floors).  The living area has hardwood floors and the kitchen has tile.  My question here would be in what area would be best to put the access into the crawl space?

Thanks for all the help.


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## ToolGuy

Only you can decide the best location to make an access hatch, as it's mostly a matter of cosmetics - where would you rather it be seen. Speaking of which, since it will be visible you'll want to make it look nice. Best thing to do is to use a thin kerf blade on a circular saw and carefully cut a nice square (or rectangle). Use a jig saw to get into the corners. That way you can use the same floor boards when making the cover for your new access hatch. I would tend to make it atleast 24" wide, which means you'll have to go through at least one joist. That in turn means you'll have to put a header on each end of your access way. If you cut the cut joists back another 3/4" your 1-1/2" thick header will support both the cut floor and the access cover. You may also want to get a nice looking recessed thumb-pull for it, so you don't have to use a screwdriver or something every time you need to open it. 

Screw jacks are good for long term use, as they don't tend to unscrew. However, treated wood posts are even better because they _can't _unscrew. I wouldn't use hydraulic jacks as the seals may go bad over time - just in case you're considering them.


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## theboomboomcars

There is a space about 3' wide between the front wall and a wood burning stove would this be an okay place to put the access or would the weight of the stove compromise the joist when we cut through it?


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## guyod

Before you cut into the hardwood floor i would be real sure there is not way of getting in from the outside.. Does the siding of the house go all the way to the ground?


I would rather you use cinder blocks as columns or at least a combination of screw jacks and blocks. Screw jacks work great until they kick out on you. i have had it happed many times. im normally just leveling floors when it happens so the floor just falls back to the original position or i have a back up in place. If this happens to your floor it will be bad.. if you do use screw jack you have to make sure they are perfectly level. The taller the jacks the more percise you have to be. im talkin about within an 1/8 of an inch in any direction.. make sure the metal plate on top the screw jack is screwed securily too the beam. im not sure what the weight capacity of the jacks are either you will want to check that when you buy them. i already had the bottom side of a jack bend in when it kicked out..


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## theboomboomcars

When I went out on Saturday I walked the perimeter and couldn't see anything.  The house is stuccoed and the stucco stops at the concrete for the foundation.  Before I do any cutting I will be sure to quadruple check that there are no current access points into the crawl space.

I haven't made any concrete plans for what to use for supports, so thank you for the tip about jacks.

Thanks for the help.


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## ToolGuy

Be sure to check under the front and back stairs. Sometimes there is an access hidden under there. 

I didn't catch it earlier, that you have a concrete foundation, and I'm surprised there is not already an access way. It should have been built-in from the beginning, for access to plumbing and such. If you're feeling especially ambitious you could put the access the outside. It would require cutting through the concrete and putting in a steel header, but then you wouldn't have to chop up your floor. Also, if a plumber or anybody has to get under your house, they won't have to tramp through your living room. 

Just a thought I felt worth mentioning.


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## theboomboomcars

It seems strange to me that there is no access either, the previous owner may have just put the new flooring over it when they did the floors.

What would an outside access look like, I may have seen it and not known.  I am pretty sure it's not under the stairs as they only go up like 6", the front has two stairs about 3" high each and the back has one stair.  All is concrete. 

I can't say for sure if the foundation is concrete or block that has been entirely mortared over.

You guys have been very helpful, thanks for all the input.


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## inspectorD

I have inspected hundreds of homes with no access. You will need to install one to figure out what is going on. This unfortunately is a common problem, folks did not want the critters to find a way in.
Usually it is done because there is no room underneath to do anything anyway.
Good luck.


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## guyod

Only 6" Steps? that is not a good sign or maybe a really good one. 

Is there only 6" of foundation all around the house..  that is going to make it almost impossible to do any thing in the crawl space like inspector said. 

there is a very small chance there is a slab or a slab with floor joist right on it.  something to cross your fingers for.


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## theboomboomcars

How would I check?  The floor does have some bounce in it, so I know it's not directly on something hard.


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## Daryl in Nanoose

As far as the Crawlspace access hatch do you have a nearby closet you can put it in.


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## CraigFL

Be aware you may have to make several tries to find a way under there. When you cut the access hole, you have to be able to contort your body down into that space. It may be easier to cut a small hole(camera size) just to see what is down there because the ground may not be level and some corners may have more room than others.


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## theboomboomcars

There are no closets over the newer part of the house.  So I don't have the convenience of hiding it in a closet. 

I have lots of experience with contortion, I have worked on cars for years and at times you have to bend your self in ways which you probably shouldn't to get to some things.

Thanks for the suggestions.


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## theboomboomcars

We got the house and have started doing some fixes and such.  I am almost to the point to make the crawl space access. 
Here is a picture of the floor that the access will be put in.  
	

	
	
		
		

		
			




I was thinking of putting it between the wood burning stove and the wall with the window in it.  I don't know if that would be a problem or not, so any advice would be appreciated.  

If it won't work there I will put it in the dining area under where the table is.

Thank you.


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## Daryl in Nanoose

theboomboomcars said:


> We got the house and have started doing some fixes and such.  I am almost to the point to make the crawl space access.
> Here is a picture of the floor that the access will be put in.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> I was thinking of putting it between the wood burning stove and the wall with the window in it.  I don't know if that would be a problem or not, so any advice would be appreciated.
> 
> If it won't work there I will put it in the dining area under where the table is.
> 
> Thank you.


Between the stove and wall sounds like a better idea than under the Dinning room table.


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## guyod

One thing to keep in mind is being able to fit long board into the crawl space.
The corner of the house does not leave much room. 

Cool looking fireplace!


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## theboomboomcars

Daryl and guyod thanks for the input.  I hadn't thought about getting th long board in the crawl space in the corner.  That does add a new thing to think about.  Which makes me kind of want to put it in the dining room.  I'll have to see what other recommendations come.


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## inspectorD

theboomboomcars said:


> There are no closets on the new part of the house, just a living room (which is where we want to put the tanks) and a kitchen with a small wall between them, there is a small, about 10' wide, dining area that connects the living and kithen areas (this area also has the wood floors).  The living area has hardwood floors and the kitchen has tile.  My question here would be in what area would be best to put the access into the crawl space?
> 
> Thanks for all the help.


Why didn't I notice this before.
You should access the crawl space first with a hole you can do more surveying through.
Since you have a kitchen area which is also part of the crawlspace, cut a hole under the stove. You can pop some tile and hide any issues and still get someway to maybe see what is underneath. You may not need an access at all, you may have the support or just not be able to fit underneath. So I would get this pre-inspection hole in first before I cut any good lookin floor.
Good luck.


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## theboomboomcars

inspectorD said:


> Why didn't I notice this before.
> You can pop some tile and hide any issues and still get someway to maybe see what is underneath.



Do you have any suggestions for popping the tile?  I have not done much with tile, other than carry it, so I wouldn't know of what to do here.  

Thanks.


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## inspectorD

You can cut the joints around each piece of tile, called the grout line.
I would then use a chisel to try to pop from the center with a piece of wood on the other piece.
I usually just break em with a hammer and replace with more tile or an access as best you can, you will never see it. 
And you only need a 1 foot square hole to start, do it by the back of the wall. You'll be fine.


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## triple D

Are there any vents at all around the addition area or the existing home that will allow a peak into the crawl. Also most important is there a crawl under existing house? Because if there is you can get in through there and cut your peep hole over the top of foundation and see under addition without harming floor. If none of this helps, I'm with the Inspector, move stove or fridge and cut access hole there. Just one tile and look with a mirror and flashlight, if it is enough height to work in than I would definitely hire a mason to cut an access in from outside to allow entrance of long 4x6, this is what you will need to run under tanks larger than 150gal. If the joist runs with tank, a 4x4 under each end of tank from bottom of joist to a pier block is fine. If dirt is soft and easy to disturb you will want to rake a flat spot and hand pour a form 24"x24"x10" and post on that on both ends. If joists run across short side of tank run 4x6 length of tank plus to reach next farthest joist and post same way with poured block. Use crack resistant fiber reinforced mix for this. If ground is dry and firm a simple pier block will suffice under these. If you cut access through foundation make sure and cut under length of joists and not under the butt ends. This way you won't need special headers over access. Just thought you might need one more opinion, always here to help and good luck.......


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## theboomboomcars

There are vents around the perimeter of the house, but there is a board in front of them so you can't actually see into the crawl space.  There is no access from the original part of the house.  

How do I tell where the joists are, so that when I do try to get visual access I don't cut through one?

Thanks for all the help you guys have been great.


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## guyod

Use the depth adjustment on you circular saw. start at 3/4'' then start going deeper if you dont make it through.  Can you take some picture of the outside of the house and include the sides with the vents and your exterior doors. maybe be can help you find a way to make an access from the outside.


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## theboomboomcars

I think we'll be going down tonight, I'll take the camera and take some pictures.


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## theboomboomcars

We went down so I was able to get a picture.  We got down there a bit late so it was dark so I had to use the flash so I was only able to get one picture before the battery died.  I forgot to reset the white balance so it turned out blue and when I got rid of the blue it was left in black and white, which is much easier to see details than the blue.





There is another vent like this on the back of the house.  The inside of the vent is covered by a board, I don't know if it's a joist or not as I don't know how to tell which way the joists are running.

We'll be going down again tomorrow or friday so I can try again to get some pictures.


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## theboomboomcars

We went down again today for pictures.  I went around to the back to get some pictures of the back vent and I could see into it more.  It looks like there is only about 6 inches between the ground and the joists.  So it looks like the original plan wont work.

We were thinking that we could cut out the floor where we will put the aquariums and put some cinder blocks, or something else, under where the joists.  To do this I would need to dig down to the hard dirt, but I am unsure what to use to fill in the space between the cinder blocks and the joists to make it a tight fit.

Thanks for any input.


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## triple D

It's going to get messy and expensive really quick if you have to tear up hardwoods or tile to get access to this 6" area....Maybe you could look again for these specific things. How tall and wide are the floor joists? Which way do they run in relation to the tanks? What's on top of them looking from underneath? Is it like 2x6 boards layed flat? Or plywood? How close are floor joists together? And how far across do they run? I know this sounds like a lot especially with the window of sight you have, but trust me, all the answers you can get will help you out....Good luck again...


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## guyod

That sucks... at least you didnt cut a hole in your hard wood floors.  if you have 2x8's support them every 6 to 7 feet, 2x10's 8 to 9 feet. You can use half blocks, bricks, pavers, ceder shingles, lumber (oak boards ideal). really anything flat and solid.


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## theboomboomcars

triple D, I wasn't able to see much, it is a small space to look into.  Perhaps the sun will come out again this coming week and I'll get some better light.

guyod, Thanks for the input.

Is there anyway to cut through the hardwood and the sub floor and then pull that as a unit off the joists?  If not can we pull up part of the wood flooring without pulling up all of it?

Here is a quick floor plan that I created with where we are thinking about putting the tanks.  We changed our mind about going for the 360 gallon, we can get the entire 210 setup for less than just the 360 gallon tank.  The joists appear to run parallel to the 210 gallon tank.  I am not sure if the Kitchen is part of the addition or the original house, it would be mighty convenient if the kitchen was part of the original house, but I would hold my breath.





The 80 gallon is along a wall.
Thanks for the help, and any additional advice.


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## guyod

You can do that. Cut a 32" or 48" (depends on the joists spacing) wide by about a foot shorter than the length of the tank under the tank. That way the tanks with hide the seam. Use the thinnest circular saw blade you can find probably will be a ply wood blade. A carbon tip will leave to wide of a gap. You have to make sure you are cutting directing over the joist and in the center. if you wander off it you are in trouble.  I would try and get some light under the house. Then take a small drill bit and drill a series of holes on the line your cutting making sure you dont see any light through the holes.


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## theboomboomcars

Thanks, that helps a lot.  

Is there anyway to tell where the joists are so I'll know where to cut?


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## inspectorD

Try some ducttape and a stick with a small 12 inch mirror under the crawlspace vent hole you had. That and a flashlight may help out.


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## guyod

Cut your ends first ,perpindictular to the joists, remember to set your depth gadge. This will locate your middle joist. From there it will be 16 or 24 inches each way. carefull not to go past the center joists with the saw. You can try drilling small holes on your saw line to find it.


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## theboomboomcars

Thanks for the info.

InspectorD- I don't think I could fit a 12inch mirror in the vent, so I don't think that would work so well.

guyod- I think I'll be able to start cutting tomorrow, I'll let you know how it goes.

You guys have been great, thanks for the help.  As always, anymore info is always welcome.


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## guyod

make sure you use cedar shingles they are about 6 inches wide and hammer them as much as possible. so you get a really tight fit between the peir and floor joists. any settling or gap will mean your floors will sag.  If you want you can even use a jack to lift up on the floor joist while you hammer the shims in.


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## theboomboomcars

Thanks for the hint.  I know I don't want sagging floors.


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## theboomboomcars

How do you connect the cuts without over cutting?


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## guyod

get your saw marks touching then use a hand saw, a series of holes or a thin chiesel /screwdriver. as long as you have a clean cut on top it doesnt matter how much you butcher the bottom.


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## theboomboomcars

Thanks for the response.  I used my long lost hand held jigsaw with the depth adjusted just above the joist, it seemed to work well.

The problem I have now is that I have cut my hole but I can't get the floor to come up.  I am not sure what to do to help it up.

Thanks for all the help.


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## guyod

Im sure its still nailed to the studs you will just have to pry it up. its probably going to mess up the floor a little not much you can do about that. you may even have to notch out a small section to get a large pry bar in.


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## theboomboomcars

Thanks for the reply.  I wanted to see if there was something else I could do before busting out the pry bar.


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## inspectorD

You could try a thick putty knife , by itself or with it under the prybar. You could also buy a thin prybar for trimwork.


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## theboomboomcars

Thanks for the tips inspectorD.  I'll be going down today or tomorrow to work on it some more.  I'll let you know how it goes.


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## theboomboomcars

We have got the floor up, and we have commenced digging the dirt out, in search for hard dirt.  The top layer was pretty hard and too a bit to get through it and it seems to be getting softer as we go down.  I don't know if this is normal, and if so how far do we dig?

Thanks for the help.

ETA:  The joists are 2x8s 16.5" apart center to center.  There is a beam in the middle of the floor, about 12' from the wall we are putting the aquarium by.  The aquarium will be running perpendicular to the joists.


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## inspectorD

Well, if you can get to the areas of the floor you need support under, try a beam.
You can dig a 12 inch deep by 24inch square piers to set it on. Then at least a 4x8 beam with 6x6 under that for posts. Also put some solid blocking in between the joists, on top of the beam to make the whole thing solid. This way you have the weight evenly distributed to the beam below.
I am no engineer and you should get one, but I at least want you to do it the best you can.
Have fun under the house, and wear some respirators....you will thank me later.


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## theboomboomcars

Boy, digging is time consuming.


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## theboomboomcars

I am just about ready to start with the concrete and having never done anything with concrete am looking for advice and tips on how to best do it.

I got some of the 12" diameter round forms on the advice of my uncle, and some 1/2" rebar.  If I am understanding what I have read, I make X's with the rebar.

My main concern is with mixing the concrete.  I got one of those plastic tubs that lowes has by there concrete.  I was guessing that that was what they were for.  Link to the tub. 

Edited to fix link

Thanks for the help, you guys have been great.


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## guyod

you dont need a perfect mix for what you are doing. just take you time in mixing though. dont use the whole bag of cement so you will have more to add when you add to much water. only add a little water at a time. you will know when you get it right. 

As far as rebar goes i dont know to much. just that it can cause more trouble that its worth sometimes when it rusts. I normally only use it to spaning a distance with the concrete or connecting 2 sections of concrete together(seperate pours)


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## ToolGuy

True, you don't need rebar for this application. 

When you mix the concrete, keep the dry concrete pushed to one end of the tub and pour water into the other end. Then pull some of the concrete into the water, mix it in, pull a little more, mix it in, and keep doing that. This way you keep the mix consistent and manageable. 

Be sure to clean that tub when you're done. It comes in real handy for gardening and many other purposes.


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## theboomboomcars

Thanks for the tips.  Now I have something to start from.  I'll keep you posted on how things go, it may be a few weeks it's finals time and so things are pretty busy at school.


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## theboomboomcars

I got it all done.  I wanted to show pictures of how the reinforcements looked and stuff, but I kept forgetting the camera as I put them in, then when I finally remembered to bring it the batteries where dead.  I really appreciate all the help, I couldn't have done it without your help.  The tank is level and the floor is holding great.

Thanks again.


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## guyod

Thats great news glad everything worked out


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## inspectorD

Glad to see the site helped you out.  
And thanks for posting those pictures so folks can understand what was goin on.


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