Flooring Problem

[drsung]

New guy here. Great Forum. I have a slight builder mess up in my garage and I would like some advice on the best way to fix it. I had a wall separating my 3 car garage. When they poored the slab they poured the footing for the garage wall all the way across without realizing there was a door. So, after construction, they busted out the footing for the door. What I have now is an uneven mess. It's a garage and no big deal, but I would like to know the best way to "smooth" it out. I have posted a pic below. I would like to even out the high spots and the "fill" the low spots with something and smooth it out. Eventually, I will epoxy over the entire thing. There is probably 1" between the lowest lows and highest highs. What's the best tool to sand the high spots? Grinder? Belt Sander? Air Chisel?

What should I use to fill it in? Would something like this work?

Here is what it looks like now:

 

[rlitman]

I would call the 800 number on the back of that container, and ask for their advice.
They'll recommend the best product from their line, and how to apply it.
Then report back here.

Seriously, I'll sometimes be standing in the HD aisle when I make the call.
The company's rep will almost always know more about the product (and the whole line, in case there's something two bays down that's better for your application) than anyone working in the store.

 

[Edger]

You need a hand held diamond grinder like these http://www.situp.com.au/Hoverhood Dust Shroud.html to level the high spots then **** out all the dust from the area and fill with epoxy grout/patching compound to level and then diamond grind it all again after it hardens.

The first time you grind expect dust to go everywhere because the surface is not level so you will only get a partial vacuum seal.

It will be very difficult to grind the edges especially the corners because it is not a long flat wall, so they must be chipped down a little (half an inch from the wall) and filled to exact level. You can use an old chisel and hammer.

If you have to rent a diamond grinder take it from lunch time one day to lunch the next so the epoxy will dry overnight before the second grind. Make sure you get an epoxy that will harden in a few hours. There are a few suppliers on these forums. Patching epoxy usually hardens much faster than an epoxy floor coating.

 

[CaptainRay]

I spent $800 on a high quality epoxy and regret it... I don't think I'll ever do epoxy again, it tends to come up. If your cement draws moisture epoxy won't stick very long.
Snap together plastic/rubber floor covering looks good and it will to solve my problem. Best company I found so far and very good customer reviews and excellent prices.
http://www.rubberflooringinc.com/gar...loc-tiles.html

Here's what Jay Leno had to say about epoxy...

 

[LegacyIndustrial]

Grind that threshold smooth, grout the low spots, grind again and done, done, done.

 

[drsung]

Grind that threshold smooth, grout the low spots, grind again and done, done, done.

What type of "grout" for the low spots?

 

[ConCretin]

Most cementitious and epoxy products don't 'feather out' well. I'd cut 1/4-1/2" deep down both sides and chip out some concrete to create a vertical edge to contain the patch. You can knock down any high spots at the same time.

You could use a diamond blade in a circular saw or grinder to make the cuts and an electric chipping hammer to remove the concrete - both can be rented.

Clean the area well and wet it down for a couple hours before applying the patch material. You want the substrate saturated but with no standing water.

I'd use a cementitious product rather than an epoxy. Epoxies tend to create a vapor barrier and can lift whereas cementitious materials breathe. The choice in materials is more about color match than anything else. We've found the products by Ardex come as close as any and work well. The product you suggested is probably fine as well.

Mix a small batch of patch material a little loose to create a slurry. Scrub it into the substrate followed immediately by the final coat of material to bring the area to grade. Trowel smooth and your done. Keep the patch moist for a few days just like you would cure a slab.

It might sound like overkill but you won't do it twice.

 

[Cryo Gal]

Easy, 3 part polymer concrete repair. Feathers smooth easily and takes coatings if you wish.
https://www.partsmaster.us/SitePages/Products.aspx?Code=05252005

 

[LegacyIndustrial]

We have a product that will outperform a cementitious product in a high traffic area like that threshold. Polymers live in a world that is less than 1" thick. Cement based products are generally weak when used this way.

http://legacyindustrial.net/cart/epoxy-concrete-patch-2-gal-hd110-p-81.html

 

[ConCretin]

I don't want to pick a fight with anyone or put anyone's product down, but unless I knew that my floor had a good vapor barrier I wouldn't use an epoxy.

We've repaired tens of thousands of square feet of bridge decks and parking garage slabs - mainly with cementitious products. The compressive strength of most products will be greater than the concrete underneath.

Every manufacturer I've ever seen (including epoxies) recommend a min 1/4" 'edge' on any repair. I wouldn't trust a feathered edge to hold.

Epoxies tend to be expensive and tricky to use for a diy'er. They obviously have their place but the OP has a simple problem and needs a simple fix.

 

[ForceFed70]

Too bad this wasn't caught before the slab was poured.

 

[LegacyIndustrial]

Pick away. I agree with you if we were coating the entire surface and it lacked a VB. This is a small area. Our products do work on bridge decks and highway transitions, they are flexible.

 

[harvero]

Bondo and similar products work great on concrete floors.

 

[ConCretin]

Pick away. I agree with you if we were coating the entire surface and it lacked a VB. This is a small area. Our products do work on bridge decks and highway transitions, they are flexible.

Fair enough.