Concrete crack patching before Epoxy

[detroitreds]

I have a 1. 5 car garage. The floor was painted with low grade concrete paint.

I would like someone's opinion on the process i should follow.

The paint is peeling off and the concrete slab has cracks (hairline and 1/4"). In my area, we have access to Rustoleum epoxy concrete repair. I plan on buying Epoxy-Coat.

Should i fill the crack, sand floor, etch and paint with Epoxy-Coat? Would the Rustoleum repair kit work well? Some complaints are that the concrete patch shows through the paint... But i don't know which paint is being used.

 

[LegacyIndustrial]

Grind, fill, grind, coat.

 

[pauls_workshop]

I have a 1. 5 car garage. The floor was painted with low grade concrete paint.

I would like someone's opinion on the process i should follow.

The paint is peeling off and the concrete slab has cracks (hairline and 1/4"). In my area, we have access to Rustoleum epoxy concrete repair. I plan on buying Epoxy-Coat.

Should i fill the crack, sand floor, etch and paint with Epoxy-Coat? Would the Rustoleum repair kit work well? Some complaints are that the concrete patch shows through the paint... But i don't know which paint is being used.

The Rustoleum patch kit is good stuff. You can mix it with silica white sand about 3 or 4 to one to stretch it out and fill in the cracks. If you grind it after filling, it will match your existing floor perfectly and won't show through much at all. If you want it truly perfect, you could go over with a final thin skim coat without the sand. Do this after the grinding on it if you do. You could also just use the epoxy-coat to do the filling as well if you had enough left over to use it for that purpose. - Paul

 

[jasonvt]

The Rustoleum patch kit is good stuff. You can mix it with silica white sand about 3 or 4 to one to stretch it out and fill in the cracks. If you grind it after filling, it will match your existing floor perfectly and won't show through much at all. If you want it truly perfect, you could go over with a final thin skim coat without the sand. Do this after the grinding on it if you do. You could also just use the epoxy-coat to do the filling as well if you had enough left over to use it for that purpose. - Paul

Is the rustoleum patch kit (Im assuming you mean the epoxyshield 100% solids patch) is good to use to fill in hairline cracks as well as expansion joints before using epoxy-coat? E-C recommends just using latex caulk to fill these, but I keep reading that isnt the best idea.

 

[detroitreds]

Is the rustoleum patch kit (Im assuming you mean the epoxyshield 100% solids patch) is good to use to fill in hairline cracks as well as expansion joints before using epoxy-coat? E-C recommends just using latex caulk to fill these, but I keep reading that isnt the best idea.

Yes, you are correct that I meant the epoxy shield 100% solids patch. You are also correct that Epoxy-Coat recommends a flexible acrylic caulk.

And the reason for my original question is because of the confusion you talked about.

 

[jasonvt]

I am leaning towards using DAP or whatever is at Lowes acrylic latext caulk for the expansion joints. I will also pick up a box of the epoxyshield to fit a couple hairline cracks and a few divets I have noticed. Ill apply both of those after degreasing and etching

 

[Shea]

Is the rustoleum patch kit (Im assuming you mean the epoxyshield 100% solids patch) is good to use to fill in hairline cracks as well as expansion joints before using epoxy-coat? E-C recommends just using latex caulk to fill these, but I keep reading that isnt the best idea.

Latex caulk for contraction joints is generally not a good idea. It is too soft and will shrink over time causing depressions where your contraction joints are. You don't want to use the RustOleum patch kit either because it does not have any flexibility. Filling in contraction joints can be a little risky and doesn't always work well in the long run. Most good contractors will fill them if asked, but will not warranty it. Here is an article explaining about the risks of filling your joints.

If you want to fill them in, use a 100% epoxy or polyurea with an elongation factor of 50% or more. The elongation factor is what will make the joint filler more flexible and be able to move with the floor. There are some polyurethane fillers by Dap I believe that fit the bill as well. I know that Legacy makes a product that people have had great luck with that will fill in your hairline cracks and works for contraction joints as well.

 

[pauls_workshop]

Is the rustoleum patch kit (Im assuming you mean the epoxyshield 100% solids patch) is good to use to fill in hairline cracks as well as expansion joints before using epoxy-coat? E-C recommends just using latex caulk to fill these, but I keep reading that isnt the best idea.

Yes, meant the 100% solids epoxyshield patch. It is good for the hairline cracks or other voids in the floor. I would not fill in any expansion joints with anything solid and would not epoxy on top of them. I don't think that is a good idea and could cause the epoxy on top to crack eventually. - Paul

 

[LegacyIndustrial]

Latex caulk for contraction joints is generally not a good idea. It is too soft and will shrink over time causing depressions where your contraction joints are. You don't want to use the RustOleum patch kit either because it does not have any flexibility. Filling in contraction joints can be a little risky and doesn't always work well in the long run. Most good contractors will fill them if asked, but will not warranty it. Here is an article explaining about the risks of filling your joints.

If you want to fill them in, use a 100% epoxy or polyurea with an elongation factor of 50% or more. The elongation factor is what will make the joint filler more flexible and be able to move with the floor. There are some polyurethane fillers by Dap I believe that fit the bill as well. I know that Legacy makes a product that people have had great luck with that will fill in your hairline cracks and works for contraction joints as well.

 

[CamarosRus]

I have left over Arizona Polymer crack filler from my job, if anybody local wants to contact me..........

 

[retfr8flyr]

Alpha Garage also offers a good product for small cracks and expansion joints called IntegraFlex 1921. It has enough flex to handle the expansion and contraction of the concrete. I will be using it on my floor.


Earl

 

[pauls_workshop]

Alpha Garage also offers a good product for small cracks and expansion joints called IntegraFlex 1921. It has enough flex to handle the expansion and contraction of the concrete. I will be using it on my floor.


Earl

There are products that can handle the expansion and contraction of the concrete in the joints, but there aren't any products that can stop the much harder and more rigid coating of epoxy above it from cracking when the concrete under it moves. It all depends on alot of variables, but epoxy can crack when used over expansion joints, even if a compliant material is used under it that in itself can handle the movement of the joints. People that want to do this should just be aware that it could crack if done.

 

[Zmw]

My garage joints were already filled with some type of concrete patch yrs ago and all the joints are cracked and junks are coming out. I have washed and gotten rid of all the loose pieces. I assume my only options are to caulk the areas that are cracked, or remove all the concrete patches myself. About 90%+ of the joint area is still filled with the path, but cracks run along the entire patched area.

Caulk over it once prep work is done and epoxy on top? Best course of action?

 

[LegacyIndustrial]

HD821 is a very good option to all of these.
Elongates but is hard.

http://legacyindustrial.net/cart/hd821-crack-sealant-gel-style-p-94.html

 

[houstonfloorcoatings]

Do not use caulk or anything flexible to fill in any cracks, holes, or pits before applying epoxy. Anything that is flexible will cause a crack in the epoxy when weight is applied, (when you walk or drive on it.) After repeated traffic, the epoxy will crack and chip away from the flexible filler underneath.

Spend a little extra money and use an epoxy crack filler.

Rustoleum makes a good one, so does Sherwin Williams, it's called GP3500.

 

[Zmw]

The previous owner filled all expansion joints with a concrete patch and I am now chiseling that out the best I can. But, it will not be perfect nor 100% even. Some of the patch stuff is really in there, and some is cracked and falling out.

Would you guys recommend I chisel as deep as I can and lay a small layer of caulking in the joint to try and get some uniformity? Or just leave it be and epoxy the joints as is. I am not sure either approach will give a 100% perfect look, I just want the best long term option.

 

[LegacyIndustrial]

Caulk will shrink.

 

[Air_Cooled_Nut]

HD821 is a very good option to all of these.
Elongates but is hard.

http://legacyindustrial.net/cart/hd821-crack-sealant-gel-style-p-94.html

I see 1 and 2 gallon but not 1/2 gallon as offered for the kit: "Please choose half, one or two gallon quantity below."

 

[LegacyIndustrial]

Sorry. We eliminated the 1/2 gallon unit. Customers complained it was never enough.
We will remove that verbiage.

 

[Armorpoxy]

We carry a Crack Repair 2 Part Epoxy Purty that works great to fill hairline an expansion cracks and joints. If your slab moves though the coating on top could develop a slight crack.

http://www.armorpoxy.com/mm5/mercha...de=A&Product_Code=AI-FP818&Category_Code=FREP

 

[bigbadktm]

You can make your own crack repair epoxy by using a 100% solids epoxy and mixing in silica flour. Make it to about the consistency of toothpaste all the way to peanut butter depending on your needs.

 

[LegacyIndustrial]

You can get the silica flour in the baking aisle, near the silica sugar.

 

[dcs Inc]

Silica sugar.... that's a good one. Epoxy thickeners are used all the time by installers. Instead of paying the extra for a ready made thickened epoxy, installers will mix their own.

 

[LegacyIndustrial]

For most folks the silica flour is an Internet-only item. It can be found in the normal places, eBay, amazon, etc... "Fumed silica"

 

[dcs Inc]

Actually they are two different products. Silica flour is produced by grinding silica sands or quartz to a fine powder. Fumed silica is a by-product of industrial furnaces. Cab-O-Sil is one I've used. It's a PIA to mix because of it is super light and fluffy making it hard to mix. Silica flour is easier to handle.

When Elite Crete installers have the need to thicken epoxy, they use our Cellulose Thickener and silica sand. Much easier to use and mix and you get great results.