Opening the perimeter concrete joints

[doge]

I'm prepping my garage for an epoxy and am wondering the best way to remove the stuff that is in the perimeter joints. I think these are contraction joints as they seem to be filled with the same stuff that seperates the driveway and garage. There is also some concrete in these joints in some spots.

Is there something I can attach to a multitool to remove it? Or maybe an angle grinder?

Also how would I smooth down the rough concrete around the edge of the garage?

I'll get some pics up in a few hours. Thanks for any help.

 

[boobag]

hammer and chisel big chunks smooth. then scraper to get remaining loose stuff.

 

[doge]

Sent from my SAMSUNG-SM-G900A using Tapatalk

 

[Armorpoxy]

Hi,
Unless these are cleaned out with a hand grinder kr a combination of tools it won't look great when coated.

Suggest you clean them out and then fill and smooth with a cementious filler product or something like our Crack Repair Epoxy Putty.

As everyone states here the secret is in the prep to get a good job.

 

[Shea]

The horizontal joint in the picture is an expansion joint with compressible fiber board in the joint. The vertical one is a contraction joint.

Expansion joints allow for expansion and contraction of two different concrete slabs or structures in order to prevent cracking, chunking, or other stress related issues from being too close together. They can be filled with a flexible joint sealer like SikaFlex but not coated. Just dig out some of the fiber board and then fill the joint. You can use a chisel of small angle grinder to clean up the edges if you want.

Contraction joints encourage cracking within the joint instead of across the surface of the slab. Those can be filled with a hard filler that has good elongation (slightly flexible) and then coated over. The filler needs elongation in case more cracks form in the joint. It will help prevent the epoxy coating from cracking directly above it.

You can read more about the difference in the two joints and what to fill them with here.

 

[doge]

Thanks for the help, I went and bought a small grinding wheel for the horizontal joint and a diamond cupped wheel for the real rough concrete.

I'm using the diamabrush to prep the smooth concrete, dap 3.0 concrete sealant for the expansion joints, and a concrete patch kit for the contraction joints. I won't coat the sealant as you recommended.

Also I looked online for 7 inch variable speed angle grinders and couldn't find much, but I did see a lot of variable speed polishers. Can I just use the diamabrush on a polisher?

I'll post some more pics later tonight when I start.

 

[tncatadjuster]

I just coat over them with epoxy filler.

http://www.acepoxy.com/acepoxy.com/Garages.html#10

 

[Shea]

I'm using the diamabrush to prep the smooth concrete, dap 3.0 concrete sealant for the expansion joints, and a concrete patch kit for the contraction joints. I won't coat the sealant as you recommended.

Keep in mind, if there is any movement or new cracking within your contraction joints, a concrete patch kit is just going to crack as well and telegraph it right through your coating. Concrete patch kits are not flexible at all, just like concrete, and will crack.

 

[doge]

Keep in mind, if there is any movement or new cracking within your contraction joints, a concrete patch kit is just going to crack as well and telegraph it right through your coating. Concrete patch kits are not flexible at all, just like concrete, and will crack.

Good advice, I think my concrete is done cracking it's almost 10 years old and from what I read so far it probably won't crack anymore. But for the outside joints I think might be moving as there is a lot of space at different spots so that's why I went with the dap.

I only started grinding with the diamabrush and so far so good. Really easy to control and low dust. I bought the bag for my vacuum and no dust is escaping.


Sent from my SAMSUNG-SM-G900A using Tapatalk

 

[LegacyIndustrial]