Caulking/Sealing Concrete Expansion Joints

[Bird]

I have concrete driveways that I guess are 18 years old. As I guess is common, they were built with wood (1 x 2?) in the expansion joints. That wood has rotted and much of it is missing. So dirt, leaves, grass clippings, etc. gets in the cracks. Yesterday I noticed a pedestrian sidewalk at an outlet mall that has some kind of gray, rubbery stuff in the joints. Can someone tell me what that stuff is and where to get it, or tell me something better to use?

 

[kenstrac]

We used silicone in the expansion joints but the joints were 1/4-3/8 wide, you have a good size gap to fill in I would try a place that sells asphalt driveway supplies and see if you can get the asphalt crack sealer that they uses on roads that is very rubbery and seems to hold up to the environment its used in very well.
Or you could dig out where the boards were and get some Trex rip it into strips 2" wide place them down in the groove2" leaving 1/4 space between slab 1/8 on each side and seal with silicone on each side that would reduce the cost of the silicone that you would have to purchase.

 

[Erik_in_Hoyt]

stuff the crack with foam backer rod, then pour crack sealer over it -- Lowe's, Home Despot, etc... all sell these types of product.

 

[tommu56]

as most have said backer rod then 1/4 to 3/8 below surface and find a self leveling product like this

http://www.quikrete.com/PDFs/DATA_SHEET-ConcreteCrackSeal.pdf

You don't want to fill the whole crack with product just the top over the backer rod check at a masonry supply to see what they have if they have the rod they will sell the compound.

tom

 

[Bird]

I had not thought about the backer rod. The cracks I'm talking about are just over 3/4" wide, 2.5" deep at least, with two of them 16' long and 3 at 8' long. I saw some tubes of sealer at Home Depot that said "rubberized" but also said it was for asphalt drives, so I didn't know whether it would be OK for concrete or not. And of course, for regular caulking gun type caulk, I don't know how many tubes it would take, but a bunch, I'm sure.

 

[Scooby074]

Ive filled gaps with sand, then sealed with Sikaflex for concrete.http://www.sikaconstruction.com/con/con-repair/con-repair-sb.htm

There are other products out there designed for this purpose, but ive had good luck with the Sika. This is on a driveway that gets plowed in the winter as well.

Your issue is the width. 3/4"+ is getting pretty wide for a caulking type product.

 

[Bird]

Your issue is the width. 3/4"+ is getting pretty wide for a caulking type product.

Yep, and I did actually measure it and it's a good 3/4" or better. And since posting the first post in this thread, I blasted the debris out of the worst one with water and then measured the depth in several places. It's actually more than 3" deep. I think I saw that Sika brand at Home Depot today, but as I said, I just didn't know what to use.

 

[tallyho8]

They usually use 1X4s here when they pour the concrete. If you clear the cracks you could probably hammer treated 1X4s (3/4X3 1/2)back in.

 

[Bird]

They usually use 1X4s here when they pour the concrete. If you clear the cracks you could probably hammer treated 1X4s (3/4X3 1/2)back in.

Yeah, that thought occurred to me, too. The one with all the board missing right now is the space between the garage door apron and the driveway, and it appears that they drove nails in the original board, so there are a few nails spanning the gap. Of course there aren't many and it shouldn't be a big deal to cut them out of there. I just hate to put another board in there to rot.

 

[kenstrac]

Yeah, that thought occurred to me, too. The one with all the board missing right now is the space between the garage door apron and the driveway, and it appears that they drove nails in the original board, so there are a few nails spanning the gap. Of course there aren't many and it shouldn't be a big deal to cut them out of there. I just hate to put another board in there to rot.

That's why I suggested Trex earlier.