# Garage floor in bad shape -can you use plywood to cover the floor?



## MiniMe (Apr 5, 2018)

Hi guys

I have a small garage and the floor is 60y old, cracked and in bad shape, smaller caster get stuck when I try to move a table or anything on small casters

I just saw this picture on Kijiji which inspired my question:









Is it common to use plywood to cover the floor? (provided it is properly set)


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## Mike_in_STL (Dec 8, 2016)

Moisture barrier is advised, unless you like soggy limp plywood. It might be best to run stringers on the floor first to give you an ability to level the floor. Use pressure treated lumber. Regardless of the load of your machines, if you run stringers, use 3/4 inch plywood and not OSB.

If you run stringers, make sure that you anchor them into the concrete with the proper fastener. Use either a Ramset type powder actuated tool or use the type of concrete fastener that you have to drill out first and insert in the hole then crank a nut down to expand the sleeve in the hole.

Keep your stringers under 12 inches on center or closer depending on the load of your machines or run blocking between the stringers perpendicular them.

I put a plywood floor in my man cave on top of the sealed cistern floor where my man cave is. The cistern floor was bowled and my plywood floor is dead flat and I'm glad I did it. I used stringers and shimmed the low spots to compensate for the floor falling away from the treated 2×4s.


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## pottz (Sep 15, 2015)

well you could but the problem is your gonna get moisture trapped under it and it's gonna rot and get mold growing.you could seal the concrete first but if you have cracks moisture is still gonna get through.maybe fill the cracks too.also you could use treated plywood.
looks like mike was typing as i was.


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## controlfreak (Jun 29, 2019)

If you do I would use some type of vapor barrier and some way to deter mold growth. You should probably do some googling to see what the proper method is. Before you do that get some clear plastic several mils thick and tape a 2' x 2' piece down so that it is sealed on the edges and leave it overnight. When you return a day later you should have a better idea how much moisture is coming out of the floor. If you have water droplets under the plastic it is a wet location. Doing this wrong could be a disaster you don't want.


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## MiniMe (Apr 5, 2018)

Hmm I have not considered the moisture aspects.
It looks like below, can it still be polished and pour concrete over it?


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## LeeRoyMan (Feb 23, 2019)

I'm not disagreeing with the above said precautions, but my experience, here out west:

Maybe it's just that I had *older concrete* and live in *a dryer climate*, but I laid down about 30 sheets of 1/8 mdf in my painting area and used gorilla tape to tape them down. I just moved, but they were there for a little over 5 years, with no mold, swelling or moisture. You can see it below, there could be 100-150 coats of overspray on it but… I didn't have any problems. YMMV


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## Phil32 (Aug 31, 2018)

It could be that your concrete floor was not designed for the loads you are putting on it, and covering it will not solve that problem. A 500 lb machine pressing down on four casters ?


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## controlfreak (Jun 29, 2019)

I am thinking a leveling compound might work. I would look up some flooring and/or concrete professionals to give you any estimate. You will quickly find out if they think it will or won't work. Even if you will do it yourself let them do some leg work and who knows, you may like the price and let them have at it. The plywood may detract from the house value but a nice level smooth floor should add value IMO. Should make sweeping easier too.

I see flooring contractors level floors all the time and install floating floors over it. I call them click clack floors and I am sure a vapor barrier is still required.


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## Mike_in_STL (Dec 8, 2016)

500 lbs across 4 casters assuming even load distribution is only 125 lbs per caster. Unless the concrete is absolute trash and turning to gravel it's unlikely the floor is that bad.


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## pottz (Sep 15, 2015)

> Hmm I have not considered the moisture aspects.
> It looks like below, can it still be polished and pour concrete over it?
> 
> 
> ...


you probably could,id call a concrete contractor and get a quote on what could be done.


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## MiniMe (Apr 5, 2018)

no that is a light weight workbench 
I added the casters, they are too small for the granularity of the floor and the table gets stuck


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## MiniMe (Apr 5, 2018)

> Hmm I have not considered the moisture aspects.
> It looks like below, can it still be polished and pour concrete over it?
> 
> 
> ...


you can't trust them sorry, they will say it has to me removed and redone
if the job is too small they won't bother
I am considering renting a floor grinder or whatever it is its name and then pour the concrete myself if possible


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## pottz (Sep 15, 2015)

> no that is a light weight workbench
> I added the casters, they are too small for the granularity of the floor and the table gets stuck
> 
> - MiniMe


yeah id switch those to 4" polyurethane casters,it will make a huge difference and cheaper than the solutions given.


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## corelz125 (Sep 23, 2015)

You could pour new concrete over it like controlfreak mentioned.You can look into the self leveling cement but you would have to look into it handling the load you put on it. If you do pour concrete on top you want it rough and might have to use a concrete binding agent to help it grab the old concrete.


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## pottz (Sep 15, 2015)

> You could pour new concrete over it like controlfreak mentioned.You can look into the self leveling cement but you would have to look into it handling the load you put on it. If you do pour concrete on top you want it rough and might have to use a concrete binding agent to help it grab the old concrete.
> 
> - corelz125


looks pretty rough right now-lol.glad you jumped in you were missin all the action buddy.


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## MiniMe (Apr 5, 2018)

> You could pour new concrete over it like controlfreak mentioned.You can look into the self leveling cement but you would have to look into it handling the load you put on it. If you do pour concrete on top you want it rough and might have to use a concrete binding agent to help it grab the old concrete.
> 
> - corelz125


there is no load there, just pedestrian traffic to call it so , a ridgid table saw ts3650 is the heaviest piece there 
so I don't think that the load is a problem
I could reinforce with some rebar or chicken wire (I just read this ) . How thin can the layer of new cement be?


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## craftsman on the lake (Dec 27, 2008)

Large wheels on the tools. over 3" and 4-6" if you can. They will roll over lots of unevenness. Small wheels even on a good floor will be stopped by a small piece of wood that a larger wheel would just roll over.
Also, unless you have a really bad floor or it's still moving you can skim it. When they put porcelain tiles down they often have to use the mastic material to level the low spots before doing it. It's hard stuff like cement and sticks really good… it holds tiles down so it should stay on the floor by itself. Maybe a line, a level, and a good large, square trowel might do it???


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## controlfreak (Jun 29, 2019)

"I could reinforce with some rebar or chicken wire (I just read this ) . How thin can the layer of new cement be?"

These are two opposing items, the thinner you are pouring the less room to reinforce. Have you ever tried to get chicken wire to lay flat? It will be like cat herding. You may be able to find a fiberglass reinforced material. I know they have this for concrete but not sure how thin you can make it. Whatever you end up with don't forget that they make tints you can mix into it while it is still in the truck so wear won't discolor the finish.


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## them700project (Aug 12, 2015)

New brit workshop just did floor in his garage to level

Think it starts here


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## Andybb (Sep 30, 2016)

Don't overthink/spend this!. Looks like about 15 mins. on your knees. I'd buy a half gallon container of mortar mix or crack sealer to smooth out the floor then buy larger softer casters and call it good. I used mortar mix 8 years ago and it's still going strong. It takes a cold chisel and hammer to dig that stuff out kinda like the glue bond being stronger than the surrounding wood.


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## corelz125 (Sep 23, 2015)

Hey Pottz, yep this year I've done a lot of concrete work. It all depends on how thick you want to pour. To use rebar or wire mesh it would have to be at least 3" thick which is over kill. The self leveling cement can be feathered out where you might have high spots. Some of the mortars you really can't go to thin.


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## CaptainKlutz (Apr 23, 2014)

+1 Call several professional concrete repair companies for quotes.
Why? 
The pics show cracks, with calcification of concrete nearby, which means floor sees regular moisture intrusion. Also see several rust colored stains (possible rebar/wire exposure), and blue colored stains (copper pipe exposure). The rough crumbling surface could be due constant water exposure from bottom, or it could be due poor quality concrete. Another issue that complicates the repair is if they installed a vapor barrier underneath when it was poured. The professionals will know best way, and cheapest way to fix it.

Depending on the response from professionals, it might be cheaper to cover it up, or it might not?

FWIW: Leveling a concrete floor is not too hard. The hard part is knowing what and how to fix the substrate before you cover it up. If not fixed, the cracks open, and the damage returns over time. Best case; you just need to level the floor with leveling compound ; worst case - you have bad concrete mix at day 1 that is slowing evolving back to sand/rocks/lime and entire floor needs to be replaced.

+1 Use larger wheels. 
With rough floors, you can't use < 3" casters anymore. Even 4" are not larger enough for most heavy cast iron tools. Rockler All Terrain mobile base has 5" wheels and easy rolls over pea gravel. Unfortunately, it is about only commercially available mobile base with large wheels, unless you make your own.

Best Luck.


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## Andybb (Sep 30, 2016)

Not that it matters but I think that floor looks like it may have originally had a rougher grade of concrete that has been coated in the past.

Remember that concrete contractors will give you a contractors solution. The floor is 60 years old. After getting some estimates I'd first try the trowel and mortar mix route. If you're not happy you can always pay to have it done.


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## tblank (Apr 8, 2010)

There are a lot of products that are self leveling epoxy that is an easy do it yourself project. After cure, it will hold up to shop tools and casters as long as the wheels aren't steel. It will help in a re-sale as well. Even Home Depot and Lowe's carry them. I'd say look into it at least.


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## MiniMe (Apr 5, 2018)

@CapitainKlutz: no exposed rebar, just stains there; the floor is 60y old obvioulsy some decay is happening
The crack you see in the picture is from settlement I think. I have been watching it for 4 years no movement or agravation.
No humidity there other than probably some natural condense when colder or warmer air enters the garage in cold or warm season

I am inclined toward the solution suggested by Andybb and tblank
tblank, could you please name the products you have in mind ? I thouhg epoxy needs cement first , can I pour it over the cleaned floor ?


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## Axis39 (Jul 3, 2019)

I've used self leveling concrete many times over rough floors in prep for tile, or carpet, or even just to leave a nice finished surface in a utility room. Just the stuff you get at the big box stores works fine.

I grew up in the Mid-Atlantic, and dealt with wet basements, garages and sheds all the time. I know the pain of plywood on concrete and the mold and deterioration… Whatever you do, try to avoid OSB. It's almost as bad as particle board as far as I'm concerned.

I remember using a product a number of years ago that was plywood bonded to a black plastic that had big bumps all over it to space it up off the concrete. That seemed like a super smart idea. But, as I recall it was not inexpensive.


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## kelvancra (May 4, 2010)

A horsey mat is 1" thick by four feet wide by six feet long. They run forty each. They ARE the seal others talk about, and are even easier on your dropped tools than would be plywood. Heck, you might even be able to catch on the bounce.

Okay, probably not. However, my dropped chisels never end up with chips in the edge. My feet don't get tired after a long day.

I only have seven, but plan on at least that many more to allow my equipment to roll from the edges without a bump.

Anyway, I think it adds insulation. I know it softens the slab for both my feet and dropped tools too.


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## unclearthur (Jul 4, 2013)

Lots of tounge and groove flooring panels like this around. Vapor barrier built in. Can screw down some 3/8" ply on top to make it look better if needed. Warmer. Softer. Brighter. IMHO a much nicer feel than walking on concrete.


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## controlfreak (Jun 29, 2019)

I hadn't thought about horsey mats. My gym did the whole floor with these and they worked great. They look like the are the same size as plywood and about 5/8 to 3/4 thick. You may have a winner here.


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## MiniMe (Apr 5, 2018)

> I hadn t thought about horsey mats. My gym did the whole floor with these and they worked great. They look like the are the same size as plywood and about 5/8 to 3/4 thick. You may have a winner here.
> 
> - controlfreak


A lot more expensive than plywood
https://www.canadamats.ca/


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## Smitty_Cabinetshop (Mar 26, 2011)

Pursue wood if possible. Good advise above to get there.


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## sansoo22 (May 7, 2019)

> A horsey mat is 1" thick by four feet wide by six feet long. They run forty each. They ARE the seal others talk about, and are even easier on your dropped tools than would be plywood. Heck, you might even be able to catch on the bounce.
> 
> Okay, probably not. However, my dropped chisels never end up with chips in the edge. My feet don t get tired after a long day.
> 
> ...


This was going to be my suggestion. We use them in my gym and they hold up to dropping just about anything on them. We try not to drop the old metal plates on the floors but if I'm dead lifting 405 or better and it feels wrong it gets dropped. The rubber mats don't care and no damage to the concrete below. A few of our bumper racks are on casters and roll over them just fine. The big bumper rack holds 10×45 pounders and rolls just fine.

We picked them up from tractor supply. They are 4×8x3/4 if i recall correctly. When i redo my shop (my garage) I'm covering the entire floor with them.


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## kelvancra (May 4, 2010)

My two top heavy bandsaws, my 8" jointer and everything else roll smoothly and easily on them, since they don't compress a great deal under weight. It's amazing they work so well protecting dropped things.

I don't plan to cover my entire shop, but want at least 21 mats when they're all in.

Since my shop is on an uninsulated slab, I think these go a long ways toward isolation the shop from the big heat sink I call a floor.

P.S. Dropping fresh eggs would, probably, make a mess.


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## kelvancra (May 4, 2010)

My mats are almost exactly 1" thick. That's a lot of rubber. I'm pushing that 70 a might hard, so I'm glad they aren't 8'. In addition to being cumbersome, they'd be heavy as two or three sheets of 3/4 ply.

They, certainly, will take a lot more abuse than plywood.


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## MiniMe (Apr 5, 2018)

So the mats don't present the humidity problem that the plywood would? Do they breed?


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## corelz125 (Sep 23, 2015)

I would check the prices between the epoxy and self leveling concrete and the amount of labor involved with each one.


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## MiniMe (Apr 5, 2018)

Can I pour epoxy on the floor as it looks right now or I need to use a grinder ?


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## CaptainKlutz (Apr 23, 2014)

> Can I pour epoxy on the floor as it looks right now or I need to use a grinder ?
> 
> - MiniMe


Maybe?

1) Depends on amount of surface height variation. Epoxy is way more expensive that leveling cement. The last thing you want to do is spend usual $80-100/gal for epoxy, and end up using several gallons to fill a low spot in floor.
2) Epoxy considered a surface coating like thick paint, seldom thicker than 1/8" thickness. With epoxy the substrate needs to be clean, with no loose, or non-uniform sharp edges. Any defects telegraph through a normal thickness layer of epoxy. This is one reason that they recommend grinding older floors to same surface finish and height. 
3) Another reason for grinding old floors is contaminates. If grease/oil has wicked into pores, you must have a uniform rough surface to ensure good adhesion.

Ask a PROFESSIONAL for a quote on epoxy floor. 
They will be able to judge the cost of filling holes with epoxy .vs. leveling cement.
Quotes are free.


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## MiniMe (Apr 5, 2018)

I am not doing epoxy it is not worth it
I will go with self leveling cement. The worst thing that could happen is to fail and have some cracks in the floor
if that happens I will either do the entire floor or do something like I have seen in Costco and Home Depot
Their floor seems to have had some large cracks which they filled with some sort of resin and then the floor was polished. Would that work?


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## Andybb (Sep 30, 2016)

> I am not doing epoxy it is not worth it
> I will go with self leveling cement. The worst thing that could happen is to fail and have some cracks in the floor
> if that happens I will either do the entire floor or do something like I have seen in Costco and Home Depot
> Their floor seems to have had some large cracks which they filled with some sort of resin and then the floor was polished. Would that work?
> ...


Yes, but you want fine cement, not something with small stones. That's why I recommend mortar mix. Easy to trowel and has more adhesive properties. Just buy a cheap plastic trowel and throw it away when done.

Like this

Or this


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