Sleepers - I need some guidance please

[Glen Blanchard]

I will be putting 2x4 sleepers (wide side down) under a sub floor in my new shop. I have a few questions about the sleepers.


Should I place them 12" or 16" on center?
I will have a perimeter piece about 6" from the walls to which the joists (I suppose they are considered joists) are fastened. Is this sufficient or do I also need cross-members running perpendicular (creating a grid-like structure) between the joists as well? If so, what spacing should I use?
I don't plan on fastening the sleepers to the concrete, but what is the preferred method of fastening the sleepers to each other? Will simple brads suffice until the sub floor is screwed to the sleepers?
Will it matter if I place the 4x8 sheets of plywood sub floor parallel or perpendicular to the joists?

[Gene Howe]

[QUOTE=Glen Blanchard;1425937]I will be putting 2x4 sleepers (wide side down) under a sub floor in my new shop. I have a few questions about the sleepers.

[LIST=1]
Should I place them 12" or 16" on center?
Depends on the strength of the floor above and weight of tools.
I will have a perimeter piece about 6" from the walls to which the joists (I suppose they are considered joists) are fastened. Is this sufficient or do I also need cross-members running perpendicular (creating a grid-like structure) between the joists as well? If so, what spacing should I use?
I would use them about every 3 feet.
I don't plan on fastening the sleepers to the concrete, but what is the preferred method of fastening the sleepers to each other? Will simple brads suffice until the sub floor is screwed to the sleepers?
Toe nail w/ #16 framing nails. A nailer is helpful.:D

Will it matter if I place the 4x8 sheets of plywood sub floor parallel or perpendicular to the joists?
No. But, stagger the seams.

[Aaron Wingert]

I'd glue the sleepers down with construction adhesive. I don't see any need to attach the sleepers to each other, as the subfloor will secure them in place when it is attached. I'd also glue the subfloor to the sleepers in addition to screwing it. Plywood orientation shouldn't matter, just keep the long edge over the sleepers. In a shop I wouldn't consider going wider than 12" oc (using 23/32" subfloor) simply because of the point loads your tools will inevitably put on the floor. I believe I'd add extra sleepers at the locations where my heavy tools like tablesaws and heavy benches would sit.

[Adam Strong]

If you are going to have heavy machinery on the floor, spacing them 12" OC would not hurt, but placing them 16" OC would suffice using 3/4 sheeting for the floor. (Between 12" centers you would have 9" open, between 16" centers you would have 13" open.)

Why place your perimeter so far out from the wall. 1" is plenty for expansion and will support the floor all the way to the wall. At 6" your sheeting would curl down toward the wall if an real weight is placed on it.

Joining the framing should be approached like any other framing project. This framing is going to see moisture which will warp the structure and make a wavy floor. Unless you intend to use a half lap and glue on all intersections, brads will not be strong enough. The easiest methods would be pocket screws or toe nailing (using screws or nail gun).

If you are using tongue and grove sheeting, blocking between the members is not necessary. If you are not using T&G, the sheeting needs to be supported on all edges, and the joints should be staggered.

[Rob Fisher]

I will be putting 2x4 sleepers (wide side down) under a sub floor in my new shop. I have a few questions about the sleepers.


Should I place them 12" or 16" on center?
I will have a perimeter piece about 6" from the walls to which the joists (I suppose they are considered joists) are fastened. Is this sufficient or do I also need cross-members running perpendicular (creating a grid-like structure) between the joists as well? If so, what spacing should I use?
I don't plan on fastening the sleepers to the concrete, but what is the preferred method of fastening the sleepers to each other? Will simple brads suffice until the sub floor is screwed to the sleepers?
Will it matter if I place the 4x8 sheets of plywood sub floor parallel or perpendicular to the joists?



1. Either will work but 16" O.C. should be fine. If you will have a lot of heavy equipment go with 12" O.C.

2. As someone else mentioned 1" from the wall should be fine. 6" is probably too much as the plywood could sag.

3. I agree that you should NOT attach the sleepers to the concrete below if this is not a climate controlled space. This will allow the sleepers and subfloor to expand and contract with temperature and humidity change. I would glue and screw the subfloor to the sleepers and that should be sufficient to hold the sleepers together.

4. Typically subflooring goes perpendicular to joists. Still need to stagger the seems. If T&G, no support needed under the none joist edges. If it is just square edge ply you should put blocking under all none supported edges.

Rob

[russell lusthaus]

I would put a moisture barrier (plastic sheeting) between the sleepers and the concrete floor, with the sleepers merely resting on the plastic - no nails going thru the plastic.

Possibly also consider laying in between the sleepers rigid insulation.

[Glen Blanchard]

I would put a moisture barrier (plastic sheeting) between the sleepers and the concrete floor, with the sleepers merely resting on the plastic - no nails going thru the plastic.



Yeah, I forgot to mention that I will be placing a plastic barrier down first.

[Joe Cowan]

I just finished. Vapor barrier, dry 2X4 pt cut to lengths no longer than 4', mostly 3'. No tapcons or nails. I put them on 16"centers and with the 3 1/2" width down, this makes it closer than a typical 2x4 wall with the edge carrying the load. I put rigid foam in between each to the same height as the sleepers, then Advantec 3/4" subfloor, then red oak 3/4" flooring. I did find that I needed to screw the end of the sleeper into the bottom plate of the stud wall, as it seems to want to rise up at the ends. I noticed this after screwing down the subfloor. I just popped a screw through the subfloor, through the sleeper and into the bottom plate.

[Glen Blanchard]

I just finished. Vapor barrier, dry 2X4 pt cut to lengths no longer than 4', mostly 3'.

Joe - Why did you limit the sections to 4'? Warped boards?

[Joe A Faulkner]

Joe, I'm still weeks away from starting on my floor. I'm curious, how much of a gap did you maintain between the subfloor and your walls?
What about the sleepers that run parallel to the walls, are they held of the wall at all?
Did you caulk the gap?
Did you glue the subfloor to the sleepers or just screw it down?
I assumed from your earlier posts that you did not toe nail the sleepers to each other correct?
How about your hardwood installation, did you put anything down between the subfloor and the hardwood?

[Tom Godley]

May I ask why you did not want to attach the 2x to the concrete?

[Rob Fisher]

May I ask why you did not want to attach the 2x to the concrete?

In an unconditioned space, leaving the 2xs "floating" allows them to expand and contract, due to seasonal temperature and humidity changes, without affecting the subfloor and finish floor above. This is also one of the reasons to have the 2xs be 4' or less. The smaller they are the less each individual piece will expand and contract. Seasonal movement is easier to handle locally rather than pushing it all to one side or the other.

Rob

[Gary Venable]

I put mine 16" on center and have used it for some time with heavy tools on mobile bases and had no issues at all. I also did not attach it to the concrete underneath as the weight of the floor and the tools have kept it in place for me with no issue there either. I used T&G plywood for the top and attached everything together with deck screws. It has been very nice and worked very well.

Gary