Thought on floating wood shop floor

Doug Sinjem

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400
Location
La Habra Hts. CA
I'm considering putting down a wood floor in my shop. I'm doing it mostly for comfort. It kills my back and feet. I've tried different shoes and the rubber mats with no luck. I have seen a couple of shops with wood floors and really liked the overall affect they have on the shop.

I wanted to run the process by you guys and get your input.

Step 1: Lay down vapor barrier. The floor is going over concrete. There is no visqueen under the slab. So the recommended practice is to put it on top of the concrete and tape the joints to stop moisture from coming through the new floor. I am not completely comfortable doing this because I think it creates moisture putting visqueen over concrete. A gentleman from Germany recommended felt over concrete which I think I like better. But I may do nothing since I'm in CA and it's pretty dry here. What do you guys think?

Step 2: Lay down 4x8 sheets of 1/2" thick sound board(fiber board). This is supposed to give the floor some cushion and resilience.

Step 3: Lay down 1 1/8" tongue and groove OSB. This is put down the opposite direction of the sound board. It is glued in the tongue and groove and the ends are biscuited and glued. It is similair to a floating laminate floor. Nothing gets fastened to the concrete.

Step 4: Sand entired floor with a floor sander. This takes out all the markings and evens the end joints.

Step 5: Apply polyurethane or similar product. Someone recommended a product called "Traffic". It is supposed to be good for high traffic areas and has a hardener in it.

I was told by my lumber suppier to go with 1 1/8" plywood sturdy floor. But the person I'm getting my info from did his whole shop (4,000 sq. ft.) with OSB and said it's holding up really good. He was told the same thing, to go with plywood. I think by using osb you get a little more cushion and comfort. Also there is no problem with putting heavy equipment right on top of the floor.

Let me know what you guys think.

Doug
 
i`m doing a residence right now.....wood over concrete.
what i`ve done is rip trex decking in half and lead anchor it to the concrete 16"oc, in between the sleepers are pieces of 1"foam board.. then i screwed down 3/4" adventek using construction adhesive between the trex and adventek......currently i`m milling 2200sqft of white-oak into random width flooring that will be glued directly to the adventek, screwed and plugged before sanding.
here`s some "firewood" ready to pass through the machines.......

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I'd think it would work, but would still do the moisture barrier of some sort. The materials would most likely still wick moisture out of the concrete and cause some mold.

Was going to suggest looking for close-outs on laminate floor, might be able to find enough at a good price. Got to thinking that this would probably be a little too slick for a shop though, especially with dust on it.

Anyway, just my .02...Good luck.
 
I'd think it would work, but would still do the moisture barrier of some sort. The materials would most likely still wick moisture out of the concrete and cause some mold.

Was going to suggest looking for close-outs on laminate floor, might be able to find enough at a good price. Got to thinking that this would probably be a little too slick for a shop though, especially with dust on it.

Anyway, just my .02...Good luck.

Darren I may take a small piece of visqueen and tape it on all four sides to the floor and see how much moisture appears. This is what I seen epoxy guys do. If I do a vappor barrier I'm leaning towards 15# felt.

Doug
 
i`m doing a residence right now.....wood over concrete.
what i`ve done is rip trex decking in half and lead anchor it to the concrete 16"oc, in between the sleepers are pieces of 1"foam board.. then i screwed down 3/4" adventek using construction adhesive between the trex and adventek......currently i`m milling 2200sqft of white-oak into random width flooring that will be glued directly to the adventek, screwed and plugged before sanding.
here`s some "firewood" ready to pass through the machines.......

View attachment 24554

View attachment 24555


Sounds like a nice floor Tod. Did you put a vapor barrier down underneath the Trex? Just out of curiosity why are you using Trex as a sleeper?

Doug
 
what i`ve done is rip trex decking in half and lead anchor it to the concrete 16"oc, in between the sleepers are pieces of 1"foam board.. then i screwed down 3/4" adventek using construction adhesive between the trex and adventek......currently i`m milling 2200sqft of white-oak into random width flooring that will be glued directly to the adventek, screwed and plugged before sanding.

Are you needing to shim the adventek sleepers (here and there) to ensure a flat floor or is the concrete floor flat enough that you don't need to worry about it?
 
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no vapor barrier, the floor is what was left of the original house, 1950`s vintage, 8" slab on top of a mountain....trex was used for two reasons,1) it`s 1-1/8" thick and works well with the foam board, 2) it`ll never rot or be affected by insects...
as far as the floor being "flat" ....between the sleepers and the glued sheeting it`s really close, an 8` straight-edge shows less than 1/8" in the worse spots and that`s good enough for hardwood that`s sanded in place.

as far as "moisture" goes the foam and adventek are both pretty impervious and i`d rather err on the side of some breathability than chance sandwiching moisture under the floor.....

every installation is going to be different......for a shop in california i`d look into felt over the concrete, adventek not chip board! and flooring nailed directly to the sheeting.....for a shop, finishing like marty did with blo is a good idea, it`s easy to touch-up and not slick...

again every install has it`s own quirks so slab conditions, drainage, interior humidity and temp difference between inside and under-slab should all be considered......
 
no vapor barrier, the floor is what was left of the original house, 1950`s vintage, 8" slab on top of a mountain....trex was used for two reasons,1) it`s 1-1/8" thick and works well with the foam board, 2) it`ll never rot or be affected by insects...
as far as the floor being "flat" ....between the sleepers and the glued sheeting it`s really close, an 8` straight-edge shows less than 1/8" in the worse spots and that`s good enough for hardwood that`s sanded in place.

as far as "moisture" goes the foam and adventek are both pretty impervious and i`d rather err on the side of some breathability than chance sandwiching moisture under the floor.....

every installation is going to be different......for a shop in california i`d look into felt over the concrete, adventek not chip board! and flooring nailed directly to the sheeting.....for a shop, finishing like marty did with blo is a good idea, it`s easy to touch-up and not slick...

again every install has it`s own quirks so slab conditions, drainage, interior humidity and temp difference between inside and under-slab should all be considered......


Tod I'm not putting anything over the 1 1/8" OSB...that is going to be the finished floor. I also considered advantech as well. But supposedly this system works good with the osb, maybe to give it some resilience and not make it too hard.


Doug
 
Tod I'm not putting anything over the 1 1/8" OSB...that is going to be the finished floor. I also considered advantech as well. But supposedly this system works good with the osb, maybe to give it some resilience and not make it too hard.


Doug

think about clean-up........osb will flake up, heck even advantek will flake somewhat after enough abuse..how `bout baltic?
 
think about clean-up........osb will flake up, heck even advantek will flake somewhat after enough abuse..how `bout baltic?


I'm not sure it will if treated with a poly or something similiar. My friend in AZ has done a floor like this and has no problem. Then again he put 5 coats of polyurethane on it. Like I said he was pushed to go with 1 1/8 plywood but went with OSB instead.

Actually osb is more stable than plywood as in less soft spots because it's engineered. So i'm assuming if I keep it sealed and dry it should hold up.

Doug
 
Here's a couple of pics from my friends floor done with the 1 1/8 osb the first one is before it has been sanded and sealed.

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Doug, I think the " TYPE" of Sealer will be the real KEY, from my experience with OSB. I am using OSB on "some" of my shop walls and started out sanding them smooth before putting them up, but when I applied the latex primer, they flaked something terrible and required a lot of filling and resanding. I tried to find a shellac based primer to see if it would eliminate the flaking problem, but to no avail in my area. Maybe the poly will not cause the flaking "IF" you Do Not use a "water based" Poly. I will be real interested in following this thread to see how it works out for you and what method you use. Your friend's floor looks really nice, and that "might" be a possible solution for me at a later date to correct the uneven floor in some areas of my shop, as well as the COLD floor in the winter AND the wear and tear on the feet and legs from the concrete.

I like Tod's idea of using the Trex for all the reasons he mentioned, and will file that idea away.
 
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Doug, I think the " TYPE" of Sealer will be the real KEY, from my experience with OSB. I am using OSB on "some" of my shop walls and started out sanding them smooth before putting them up, but when I applied the latex primer, they flaked something terrible and required a lot of filling and resanding. I tried to find a shellac based primer to see if it would eliminate the flaking problem, but to no avail in my area. Maybe the poly will not cause the flaking "IF" you Do Not use a "water based" Poly. I will be real interested in following this thread to see how it works out for you and what method you use. Your friend's floor looks really nice, and that "might" be a possible solution for me at a later date to correct the uneven floor in some areas of my shop, as well as the COLD floor in the winter AND the wear and tear on the feet and legs from the concrete.

I like Tod's idea of using the Trex for all the reasons he mentioned, and will file that idea away.


Norman I stated the type of poly my friend used in the above post and am assuming it's not water based. But another friend recommended a water based product called "traffic" I'll see if I can find the link and post it. it is suppossed to be good stuff.

I like the idea of trex to if I was using a sleeper system. Mine is going down over 1/2" sound board. My floors are uneven and my shop/lumber carts roll around so this will correct the problem after I scarify the high spots and fill the low spots on the concrete floor. But the main reason is for cofort and to reduce the wear and tear.

Doug
 
Norman I stated the type of poly my friend used in the above post and am assuming it's not water based. But another friend recommended a water based product called "traffic" I'll see if I can find the link and post it. it is suppossed to be good stuff.

I like the idea of trex to if I was using a sleeper system. Mine is going down over 1/2" sound board. My floors are uneven and my shop/lumber carts roll around so this will correct the problem after I scarify the high spots and fill the low spots on the concrete floor. But the main reason is for cofort and to reduce the wear and tear.

Doug

Doug, "IF" you start to use ANY finish that is "water based", I would Highly Recommend that you take a fourth or half sheet of the OSB to do a sample test, and sand it and then apply that finish to it to see if it raises the flakes like it did on mine. After sanding again, I decided to try using spackling compound as an easy filler, and even that raised flakes again, and that was when I realized that it was the water that was causing the flaking problem. Kilz does make one primer that is shellac based, but I could not find ANY place that stocked that particular primer anywhere in this area, and all their other primers that are available here are water based. (you wouldn't want to use the Kilz though since you plan on a clear finish). I had another thought, I wonder if the 1 1/8" OSB that your friend used could possibly be made with a different binder than the OSB that I have. Mine is 5/8" or 7/16" (IIRC) that I over bought 18 yrs ago for a remodel project and never used and have stored it properly in a dry place and it still "looks" like the day I bought it.

What do you use to fill the low spots in your floor? I've not had very good luck getting a decent bond with anything that I have tried in the past, or it broke up if it was less than an inch and a half or two inches thick. (I know you know the materials and Tricks, since you've been in the concrete business in a BIG way).:D
 
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Doug, "IF" you start to use ANY finish that is "water based", I would Highly Recommend that you take a fourth or half sheet of the OSB to do a sample test, and sand it and then apply that finish to it to see if it raises the flakes like it did on mine. After sanding again, I decided to try using spackling compound as an easy filler, and even that raised flakes again, and that was when I realized that it was the water that was causing the flaking problem. Kilz does make one primer that is shellac based, but I could not find ANY place that stocked that particular primer anywhere in this area, and all their other primers that are available here are water based. (you wouldn't want to use the Kilz though since you plan on a clear finish). I had another thought, I wonder if the 1 1/8" OSB that your friend used could possibly be made with a different binder than the OSB that I have. Mine is 5/8" or 7/16" (IIRC) that I over bought 18 yrs ago for a remodel project and never used and have stored it properly in a dry place and it still "looks" like the day I bought it.

What do you use to fill the low spots in your floor? I've not had very good luck getting a decent bond with anything that I have tried in the past, or it broke up if it was less than an inch and a half or two inches thick. (I know you know the materials and Tricks, since you've been in the concrete business in a BIG way).:D


Norman now I understand what you are saying about the water based. I will try and find out about the binders in the osb. I know the technology has changed over the years.

As far as filling low spots there are several products that go from a feather edge to say about 1/2"....ardex being one. We have a place out here called Roseburrough tool that have several and they do ship all over the world. But Whitecap carries many different types of levelayer material and I believe they are nationwide. Also there are many companies doing what's called a "stamping overlay" they pour a thin layer of maybe 1/4" over the floor and then stamp and impression in it. most of they product come in 30# to 50# bags of powder and are mixed with water and or hardener.

Doug
 
I think trapping moisture under a vapor barrier is asking for trouble. Instead, i'd make it so that the slab can "breathe". Mold will be an issue otherwise. Just about every house has mold in it somwhere, and i know some molds are very toxic at low levels. My greater concern is that any mold when given ideal growing conditions (such as a vapor barrier over a ground slab) will take off and spread.
OSB or plywood will breathe about as well as the slab, but the poly will tend to become a membrane of its own. As your friendly neighborhood architect, i'd recommend no vapor barrier over the slab, and give the floor some form of passive ventilation (occassional vents drilled into each sleeper space). If nothing else, i'd put some vent holes, or a floor register grill at each end between each sleeper. Moisture permeates the slab everywhere, but moreso near the exterior walls (hydrostatic pressure works hardest here and always pushes vapor up at the groud slab / wall joint) and at cracks and slab penetrations.
I like the idea of trex sleepers - rot free.
Any vent holes should be located so they collect minimal trash, and configured so they can be cleaned out (removable grills or holes that can be vacuumed).
Paul Hubbman
 
I think trapping moisture under a vapor barrier is asking for trouble. Instead, i'd make it so that the slab can "breathe". Mold will be an issue otherwise. Just about every house has mold in it somwhere, and i know some molds are very toxic at low levels. My greater concern is that any mold when given ideal growing conditions (such as a vapor barrier over a ground slab) will take off and spread.
OSB or plywood will breathe about as well as the slab, but the poly will tend to become a membrane of its own. As your friendly neighborhood architect, i'd recommend no vapor barrier over the slab, and give the floor some form of passive ventilation (occassional vents drilled into each sleeper space). If nothing else, i'd put some vent holes, or a floor register grill at each end between each sleeper. Moisture permeates the slab everywhere, but moreso near the exterior walls (hydrostatic pressure works hardest here and always pushes vapor up at the groud slab / wall joint) and at cracks and slab penetrations.
I like the idea of trex sleepers - rot free.
Any vent holes should be located so they collect minimal trash, and configured so they can be cleaned out (removable grills or holes that can be vacuumed).
Paul Hubbman

Paul I do agree with you. Only problem is, I'm not putting down sleepers and have never considered it. The idea behind this floor system is to put down 1/2" sound board directly over the concrete the the osb over that. This gives it the cushion and comfort. I believe Tod threw that out there regarding a floor he was doing.

I don't like the idea of putting visqueen right over the concrete because I think it causes condensation and like you said leads to mold. That's why I was considering 15# felt in lieu of visqueen. But then again I may put nothing because I don't think I have a moisture problem. Technically the visqueen should be under the concrete covered with 2" of sand. I guess when I get ready to move forward I will have to make that call.

Doug
 
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