Advice for old concrete

[Merbesfield]

I have a old 24x24 garage that I am rehabing for my shop space. It is a basic residential detached garage. The concrete is old and spalling quite bad. I also have to add a thin layer, about 1.5” to zero where the floor was poured too low at the entrance. I have researched how to do the addition that will supposedly hold up and bond to the old floor, but what I am not sure about is how and what to finish the floor with once this is done. Can anyone make recommendations on coatings or whatever options I might have? Again, the concrete is old and very porous at this point.

PS. Thanks in advance.

 

[tncatadjuster]

What is the thin layer composed of? Pics always help.

 

[Merbesfield]

I haven’t don’t the thin layer yet. If I recall it is an epoxy based concrete that first requires a bond coat to be applied to the old concrete than apply the leveler. I did the research and then put it in the file until my crews have time to do the work. As for pictures, really nothing to photograph other than a real ugly garage. At this point I am just doing my research and making plans. This is a small garage out back of my home. My main shop is behind my office. This garage/shop is more of a parking garage that needs some TLC.

 

[tncatadjuster]

Ok, then the leveling compound will have guides for top coating. No way to help until that product is specified.

 

[DHC-2]

I had the same issue. Deteriorating concrete surface, and a high spot in the middle of the floor of nearly 1.5"
I used dry pack, adhered to the floor with thinset for the areas down to about .75", self-leveling cement for the rest, followed by porcelain tile.
I also did an antifracture membrane, but that may have been overkill.

 

[Merbesfield]

I had the same issue. Deteriorating concrete surface, and a high spot in the middle of the floor of nearly 1.5"
I used dry pack, adhered to the floor with thinset for the areas down to about .75", self-leveling cement for the rest, followed by porcelain tile.
I also did an antifracture membrane, but that may have been overkill.

How has it held up? How long has it been done? I assume you used the AF mat over the repairs and under your tile? You process sounds similar to what I am considering. What is “dry pack”. I am in the Hardscape Construction business and we have always used AF mat when mortar setting pavers over interior concrete but I am not experienced at having to level floors especially old failing concrete. One that I had was to overlay my old concrete with a sand set paver to avoid having bonding issues.

 

[Armorpoxy]

We carry these products referred to as Self Levelers. We are a master distributor for Laticrete Drytek.

Generally speaking for them to work well you need to prep the floor well (grinding or shot blasting), prime with your manufactuter's bonding primer, and then lay out the material.

The way to control the height since it's very difficult to control visually is to 'pin' the floor by putting in small plastic pins for every 50 sq ft or so (we carry these) and you trim the pins down to the level you want. You set the pin heights with a laser and measuring apparatus. When you apply the leveler you bury just up to the top of the pins submerging them. Attached is a photo of one of the floors our www.prep-crete.com Insallation Divsion pinned prior to pouring out 29,000 sq ft of leveler.

Then you can coat over the leveler.

 

[Merbesfield]

We carry these products referred to as Self Levelers. We are a master distributor for Laticrete Drytek.

Generally speaking for them to work well you need to prep the floor well (grinding or shot blasting), prime with your manufactuter's bonding primer, and then lay out the material.

The way to control the height since it's very difficult to control visually is to 'pin' the floor by putting in small plastic pins for every 50 sq ft or so (we carry these) and you trim the pins down to the level you want. You set the pin heights with a laser and measuring apparatus. When you apply the leveler you bury just up to the top of the pins submerging them. Attached is a photo of one of the floors our www.prep-crete.com Insallation Divsion pinned prior to pouring out 29,000 sq ft of leveler.

Then you can coat over the leveler.

Thanks for reply. My concern is the prep of the old floor. It is in really bad shape and I’m not sure I would ever hit solid concrete. It appears as though the concrete is deteriorating and crumbling. I haven’t tested anything to see if it gets more structural as I chip down. I was also thinking there must be some sort of densifier like there is for soft punky rotted wood. Something that can be poured on and absorbed into the concrete prior to adding a layer. Then the decision would be what to cover the floor with. A thinner porcelain tile or a thicker paver brick. I like the idea of porcelain but not if the substrate isn’t structurally sound enough to bond to. If not sound I could lay a thicker concrete paver over the entire floor. I am in the paver business so that would be easy, but rolling floor jacks or mechanics chairs around on lots of joints doesn’t sound very nice. Prefer smooth, so for this reason plain concrete works well.

 

[Garage Flooring]

I have a old 24x24 garage that I am rehabing for my shop space. It is a basic residential detached garage. The concrete is old and spalling quite bad. I also have to add a thin layer, about 1.5” to zero where the floor was poured too low at the entrance. I have researched how to do the addition that will supposedly hold up and bond to the old floor, but what I am not sure about is how and what to finish the floor with once this is done. Can anyone make recommendations on coatings or whatever options I might have? Again, the concrete is old and very porous at this point.

PS. Thanks in advance.

Thanks for reply. My concern is the prep of the old floor. It is in really bad shape and I’m not sure I would ever hit solid concrete. It appears as though the concrete is deteriorating and crumbling. I haven’t tested anything to see if it gets more structural as I chip down. I was also thinking there must be some sort of densifier like there is for soft punky rotted wood. Something that can be poured on and absorbed into the concrete prior to adding a layer. Then the decision would be what to cover the floor with. A thinner porcelain tile or a thicker paver brick. I like the idea of porcelain but not if the substrate isn’t structurally sound enough to bond to. If not sound I could lay a thicker concrete paver over the entire floor. I am in the paver business so that would be easy, but rolling floor jacks or mechanics chairs around on lots of joints doesn’t sound very nice. Prefer smooth, so for this reason plain concrete works well.

As I think you have realized, if you never hit good concrete neither the leveling compound nor the epoxy may hold. If you are going to do a coating, I would highly suggest you have a professional give you an estimate on the repairs. Best case, you are able to utilize them. Worst case you have a better idea of exactly how bad it is.

If you decide not to repair it; go with a floor covering. I will need some pics to make a suggestion

 

[Brett K]

As I think you have realized, if you never hit good concrete neither the leveling compound nor the epoxy may hold. If you are going to do a coating, I would highly suggest you have a professional give you an estimate on the repairs. Best case, you are able to utilize them. Worst case you have a better idea of exactly how bad it is.

If you decide not to repair it; go with a floor covering. I will need some pics to make a suggestion

I will likely be using this product on my floor in the future. How durable is it and how thin can you feather it around the edges. I have a small area about 6’ X 8’ that needs to be filled about a 1/2 inch. There is also a slight slope to the doors. Would that give me a problem in keeping the product where I want it?

 

[Slowgsr]

Why not break out the old concrete (easy for any crew).

Then repour? I did this to 1/2 my shop and my house garage. Gave to a chance for proper subgrade, I put foam insulation & poly, and rebar. Then a repour. Now its all epoxied and beautiful.

Concrete is cheap for what it is.