Shop floor/screw or nail subfloor?

[Joe Cowan]

I am installing a wooden floor in my shop this weekend. It will be 2X4 sleepers, rigid foam and 3/4" Advantech subfloor. I bought screws but my carpenter, that will be doing this, suggests using an air nailer to attach the subfloor. My sleepers will have a strip of 1/2 ply (really 7/16") to help build it up to meet the same height of the surrounding rigid foam and will end up being 1 15/16" thick. Will this 1/16" difference create a squeaking floor over time as the nails slip up and down? Will the rigid foam compress enough as we work on it to make the heights even? Should we use construction adhesive? Am I showing that I have a female side by worrying about such a small thing?

[Alan Trout]

I always screw subfloors and use subfloor adhesive. It is the only way to minimize squeaks and pops. Most guys do not like to screw and want to use ring shank nails because screwing the floor takes more time.

Good Luck

Alan

[Darren Almeida]

Screwing the floor will take more time, but it is the right thing to do. I used stainless, square drive screws. You will need to pre-drill the advantek - it is very dense.

I had my nephew help me put the floor down, and his time was limited. We used a nail gun to nail down just the corners and center of the plywood. Then after he left, I went back and drilled and screwed the whole floor by myself. You could do the same thing with the carpenter.

I used 1.5" foam so I didn't have to worry about plywood shims. So I can't help you there.

Good luck.

- darren

[Joe Cowan]

Screwing the floor will take more time, but it is the right thing to do. I used stainless, square drive screws. You will need to pre-drill the advantek - it is very dense.

I had my nephew help me put the floor down, and his time was limited. We used a nail gun to nail down just the corners and center of the plywood. Then after he left, I went back and drilled and screwed the whole floor by myself. You could do the same thing with the carpenter.

I used 1.5" foam so I didn't have to worry about plywood shims. So I can't help you there.

Good luck.

- darren

I wish I could find the 1 1/2" here in my town. That is what I would do.

[Gene Howe]

I wish I could find the 1 1/2" here in my town. That is what I would do.

Do they stock 3/4? If so, double it with a few beads of construction adhesive between. Can't your local guys order 1 1/2" for you?
I'd travel a few miles for 1 1/2", were it me.

As has been said, screwing it is the way to go.

[Chris Friesen]

Use subfloor adhesive and screw it with self-drilling self-countersinking screws.

Lee Valley carries the Robertson brand, which are far superior to the flooring screws at the Borg (they kept snapping off on me). I'm sure there are other places to get decent ones as well.

[Bob Riefer]

+1 on using screws - side benefit is that replacement later, or lifting a sheet for any reason, is much easier

[Michael Heffernan]

I used Advantech for the flooring in my shop. I used star drive outdoor deck screws from HD, no construction adhesive. Screwed it down every 8" on each sleeper. No pre-drilling. No squeaks either.
If you ever need to replace a board, don't use construction adhesive. Screws should work just fine.

[Joe Shinall]

Can't help you with the floor but I can answer your very last question. YES!!!

Sorry, couldnt help it.

[Michael Heffernan]

Joe,

I just re-read your post.
Are you saying that you are putting in 2" rigid foam in a 1-15/16" deep sleeper bay? If so, I don't think that's a good idea. Rigid foam insulation board is not meant to be compressed. You may have potential problems with the decking coming loose and having a slightly uneven floor.
Better to go with 1-1/2" foam board or use 5/8" ply strips to build out the sleepers. Or you can even get 2x3s and rip them down to slightly wider than 2" and frame them on edge.
Better to have a little space between the foam and the deck.

I am installing a wooden floor in my shop this weekend. It will be 2X4 sleepers, rigid foam and 3/4" Advantech subfloor. I bought screws but my carpenter, that will be doing this, suggests using an air nailer to attach the subfloor. My sleepers will have a strip of 1/2 ply (really 7/16") to help build it up to meet the same height of the surrounding rigid foam and will end up being 1 15/16" thick. Will this 1/16" difference create a squeaking floor over time as the nails slip up and down? Will the rigid foam compress enough as we work on it to make the heights even? Should we use construction adhesive? Am I showing that I have a female side by worrying about such a small thing?

[Joe Cowan]

Joe,

I just re-read your post.
Are you saying that you are putting in 2" rigid foam in a 1-15/16" deep sleeper bay? If so, I don't think that's a good idea. Rigid foam insulation board is not meant to be compressed. You may have potential problems with the decking coming loose and having a slightly uneven floor.
Better to go with 1-1/2" foam board or use 5/8" ply strips to build out the sleepers. Or you can even get 2x3s and rip them down to slightly wider than 2" and frame them on edge.
Better to have a little space between the foam and the deck.

Yes, it will be a 1 15/16" thick sleeper with 2" foam between them. Too late to change as it will be delivered to my home at noon today. I am thinking that when I screw the ply to the sleepers, it will actually pick the sleepers up off the concrete by 1/16th inch and then the compression of the foam with the weight of the flooring, will settle it back down to the concrete. I know compression hurts the R value of the insulation, but this small amount will not hurt much and it will still be much greater than what I had before.

[Chris Friesen]

Yes, it will be a 1 15/16" thick sleeper with 2" foam between them. Too late to change as it will be delivered to my home at noon today. I am thinking that when I screw the ply to the sleepers, it will actually pick the sleepers up off the concrete by 1/16th inch and then the compression of the foam with the weight of the flooring, will settle it back down to the concrete.

Actually, I'd second the notion to use 5/8 ply. foam board doesn't compress well so you'll put extra pressure on the subfloor/sleeper joint every time you stand right over a sleeper.

Do it right the first time.

[Joe Wiliams]

Since the materials are already on the way... Maybe put a layer or two of felt paper or another material over the sleepers to make up the difference?

[Joe Cowan]

I stressed myself trying to come up with something to add to the 1/2" ply to build up the sleepers. Then I read this forum again and realized I had temporary brain damage. Just go out and get some 5/8" ply and use that. How simple. We started yesterday morning about 8am and finished around 5:30. Very easy and looks great. The only thing I do not like is the step down in front of my 8' garage door. I have my planer in front of the door and use this space to mill long boards. This up and down (and breaking some ankles) will get old after awhile. I am thinking of taking a hardwood 2X8X8 or 2X10X8 and putting appropriate angles on each side along with hinges on one side and creating a flip down ramp that will come up when the door is down and rest against the vertical side of the interior door face, and lay down when the door is up and give me a more gentle slope to come in and out of the shop. Any ideas would be appreciated.