Q: About covering exp/contraction joints in garage floor shop

Patrick Here's a few links of you.

I have used all of these products with great results.

Dave

I filled my expansion joints by stuffing an appropriately sized foam backer rod into them - about 3/8" down, running the full length of the joint, then just running a bead of caulk. It worked just fine, and was dirt cheap.

Rob

Check with your paint manufacturer. I got some epoxy paint and I believe, I haven't checked, tells me what to do for joint coverage. You want to make sure that whatever you're using is compatible with the paint.

Check their website, it might help.

MJ Wallace

I didn't see any mention of how big the slots are but if you're talking about those 1/4" crack stoppers just paint the floor first and then fill them with your choice of something in a caulking gun. Butyl rubber would be my choice but dont get any on ya.

The reason for painting first is that, IME, butyl rubber, latex caulking and RTV will all eventually lose their grab if applied direct to the concrete.

If you mean something wider than 1/4", just rip some scrap lumber to size and lay it in. You dont need a lotta strength unless the joints are really wide. Paint over it and you're done.

Other things that would work would be thinset, plaster of paris and Ardex. This last is a thin, pourable, self-leveling compound for building up floors, but it would work well in this situation. Expensive tho, $38 for a 55# bag that will do 10 sq ft to a depth of

I've been doing mine with leftover saltillo tile grout. seems to be working fine.

Good call. I completly forgot about grout. I might also mention that none of the products talked about so far will, in any way, interfere with the joint and keep it from doing what it's sposed to.