# Expansion Joint Filler



## qrs

I have an expansion joint that I would like to fill.  The EJ is located at the point underneath the roof of my carport where the concrete carport slab meets the concrete driveway.  Although this is under the edge of the carport roof, this EJ does get wet from a hard or wind driven rain.

This EJ is almost 3/4" wide and is quite deep.  I am thinking that I can use some sand to fill in the bottom first and then use a backer rod before applying a type of sealant.

Lowe's has two things that might work.
1) DAP Concrete and Mortar Filler and Sealant - $4.16 per 10.1 oz tube.
2) Commercial Grade Quikrete Polyurethane Sealant (Self-Leveling) - $6.76 per 10.1 oz tube.

Any suggestions?
Thanks in advance.


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## slownsteady

My first reaction is; if you fill it with a concrete product, then it can't expand. Probably not a good idea. I don't know these products well enough to judge whether they have enough flex to do both jobs (allow expansion and fill the gap). I remember a while ago that guys would use roof shingles cut to fit & stuffed into the joint, although I suppose a silicone product would work better.


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## qrs

Exactly...I do understand that whatever goes in there has to be flexible.  The tar like stuff that they use for streets would be great, but I am looking for something that I can do myself without creating a huge mess.  Thanks!


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## slownsteady

How about driveway sealer on top of sand/gravel?


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## itsreallyconc

backer rod & sealant alone is the correct method,,, ask me - have done 100s of miles of that item,,, IF you feel the need to insert anything under the backer rod, use vermiculite


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## RnDGuy

There are some new expansion joint fillers on the market now in the Houston area - faster, cheaper, and way better looking for a DIY install, as almost no skill is involved.  These fillers are made of rubber or flexible PVC, and generally come in a roll in a couple of different colors.  Trim-A-Slab works for replacing 1x4 expansion joints with rounded edges.  Just clear down to about an inch and a half, and press in, no prep needed.  There's another one if your joints are bigger.  It goes by Slab Gasket, and may need sand under it as a prep.


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## Nestor_Kelebay

Maybe ignorance is bliss, but I'd be asking myself whether it's important to keep water out of this expansion joint.

You live in Louisianna, where you get plenty of rain, but it's rare for the ground to freeze in the winter time.  So, frost heave is extremely rare.

Also, if your driveway and concrete garage slab are surrounded by lawn, then the ground/aggregate under the slab and driveway are going to get wet with or without water proofing this expansion joint.

So, if caulking the joint isn't going to provide any benefit cuz water is going to get under that slab anyhow in a rain, then why wouldn't something like this be the best solution:







And, if push came to shove and you wanted to waterproof that expansion joint, a bead of that black plastic roofing cement would do that while sill allowing for movement of the slabs.  And, that roofing cement would last forever since it would be protected from exposure to the Sun's UV light by the extrusion itself.

You can also get this same extrusion profile in aluminum and stainless steel.  Just ask for "Tee Bar".


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## itsreallyconc

placing anything in a joint that doesn't allow for the expansion & contraction of conc will hasten the degradation of the jnt surfaces by encouraging joing spalling - here's how it works - just basic high school physics, btw,,, cold makes a liquid expand & solids contract - this means in an louisanna summer, the day's sun causes the slab to expand &, at nite, cooler temps allow it to contract,,, this results in the jnt width changing all the time,,, s/s jnt fillers don't allow any ext/contr therefore the jnt walls & surface edge near the jnt will eventually spall.

if anything else were better, i'd sure aci/icri would recommend it & state dot's/the feds/architects/engineers would be using them,,, we don't buy any joint sealant at apron stores - rather, seek out your local const cupply house where you can find closed cell backer rod & silicone jnt sealant.

the main reason for sealing a joint is to keep incompressible junk OUT of the jnts so when the slab expands, there's room for it to do so while not allowing ea slab to touch its adjoining slab therefore no grinding/spalling,,, the 2nd reason is to keep water out of the sub-grade & soaking the base therefore softening it & causing it to lose support capabilities for static or dynamic loading.

we have used s/s jnt systems INSIDE airport terminals ( newark, atl, ny, boston ) but, because the temp's controlled, slab size remains constant,,, if there're any other jnt sealing pro's on this forum, ask them,,, this should be enough to end this thread - if you're still in a quandary, remember its always YOUR driveway,,, the jnts in mine're sealed correctly.


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## RnDGuy

You won't see these used by many folks yet, as they are new.  Here is one, installed.




It sits flush or below the slab surface, and won't affect slab expansion or contraction.  It should be more dependable in case of a growing joint/shrinking slab.  Polyurethane filler must be stretched, and it requires a good bond on both sides of the joint to keep it from delaminating, like this one.


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## itsreallyconc

that's a good idea however most residential driveways're installed by the cheapest guys the bldr could find meaning jnts're groov'd or formed rather'n sawcut,,, even IF they were sawcut, typically only a .125" ( 1/8" ) blade wouldn've been used,,, by now, everyone's gone & the bldr can't ee your house from his house    that strip seal reminds me of neoprene jnt seal - at 1 time very popular for jnt sealing & resealing old jnts in good condition,,, $, ease of install, & method for resealing jnts knock'd neoprene out of the market.

the stuff typically used for crk-sealing on streets is usually astm - d-1190, astm - d-3405, or fiber reinforced asphalt cement,,, typically its applied at 370-400f & street sealers use squeegees or over-banders,,, you don't want that mess on your d/w,,, at least i don't


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## RnDGuy

Most expansion joints in the Houston area WERE 1x4 redwood, pressure treated, or perhaps cedar.  Anything 7-10 years old is pretty much GONE.  The filler pictured above replaces 1x4; does not need a sawcut, or anything fancy.
Having installed this type, and caulk, I can say that for a DIY weekend project, the guy installing this strip will be kickin' back watching football while the guy caulking will still be on his knees squeezing his gun 
30+ linear ft per minute to install is not hard to do with the rubber filler.


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## itsreallyconc

golly gee, never applied caulk - wrong material, anyway,,, this stuff works IF the jnts in good condition but that's about it to me


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## RnDGuy

I'm just using 'caulk' generically to be the tube dispensed goo of your choice.  There another whole thread-worth of debate on which goo folks 'should be using'.  Most homeowners will probably be using 10 oz tubes, with what they can find at a local store; DAP or maybe Quickrete brand.
I see a lot of 5 and 10 foot repairs, the rest of the driveway untouched, where the homeowner gave it a try, and decided it wasn't going to work for them.
Usually a combination of too much work, too expensive, or requiring more skill than the homeowner has.


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## slownsteady

...on my knees, squeezing my gun...now, that's where I want to be!


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## billhead1

Pour Sand into cracks and top off with Brick Paver Sealer, which will cure as hard as a grout joint.


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## jonathandvcrane

where can you find this product? Name/Brand? the rubber looking joint filler


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## stadry

he MAY be talking about neoprene which's generally used on hgwys, bdges, & airports or WAS until silicone came along,,, d s brown is the only source i know for neoprene joint seal - it generally comes in 500' rolls in a box OR wood drums weighing 1,800#,,, you'll also need the lubricant to install it + an install tool - you can rent that from cimline, inc.


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