Replies

1. 
   DaveRicheson | Sep 03, 2010 06:20am | #1

   I have used two part anchor bolt epoxy to fill an open  joint at the wall and a concrete floor. It has been in there for two years now and hasn't moved.

   I would say your plan should work.

   A standard method of repairing cracks in poured foundation walls is to use an epoxy injection technique. The epoxy for that process is a thinner mix than the anchor bolt stuff. So you may need to pour it in slowly and maybe do it in stages to avoid trapping air pockets.

2. 
   rdesigns | Sep 03, 2010 09:35am | #2

   Epoxy will bond and seal, but will not tolerate much movement. You say there's no evidence of continuing movement, so it might be OK.

   I would go with the Sika, and save the anchoring epoxy for anchoring.

3. 
   mans835 | Sep 17, 2010 11:39am | #3

   To thin the epoxy

   When filling small cracks I usually add some solvent to the epoxy, it makes it thinner and epoxy fill the crack better.

   http://www.house-building-in-russia.com

4. 
   Clewless1 | Sep 18, 2010 09:16am | #4

   Maybe the pourable urethane (I think that's what it's called)? They use that to seal all kinds of concrete joints and stuff (e.g. for radon sealing and such).

5. 
   slykarma | Sep 19, 2010 01:17pm | #5

   movement makes the decision

   Epoxies like anchoring compounds are rigid and inflexible. You don't mention the size of the slab and whether it is on compacted grade or over framing, so we don't know the circumstances that caused it to crack in the first place. If things are still moving due to settling, slab loading or expansion/contraction, then epoxy or acylic fillers will eventually fail. Sikaflex caulks are designed for jointing concrete slabs and wall panels where movement is a given, but they won't have the hard finish you might be looking for.

   If the cracking is extensive and wide, you might try an inexpensive mix of portland cement, fine sand and a concrete bonding agent. (For fine cracks less than 1/8" wide, use a mix without sand). Wet the slab with a spray bottle and keep it damp while you apply the patch mix. Trowel it in, let it cure a few days, then gently grind off the excess. This will also be a rigid patch susceptible to failure if further movement occurs, but a lot less expensive failure than epoxy if the cracks are large. Sikaflex does a great job but will likely not match well the existing concrete for both colour and surface texture.