Building Suspended Floor Frame

[tjhdexter]

Not really done a lot of DIY before but I've been clearing out the shed (outhouse) and am looking to turn it into a bar/reception area. First thing I want to do is build a suspended floor so I can insulate underneath as the existing floor is concrete. Would also be useful for putting carpet/laminate down. Have a rough idea of how to build the frame just not sure what type of wood I would need to do it? Any advice would be appreciated.

Thanks,
Tom.

 

[Burnerman]

Well Tom, you can't be sure that the floor of the outhouse has any damp proof membrane down there.....it's possible to paint one on though, using Permagard products or similar.
Any timber needs to be pressure treated, maybe 50mm wide and a thickness to suit. The gaps there can be filled with Kingspan slab insulation.
On top of that you can use a waterproof chipboard (22mm) followed by laminate if you wish but any damp issues must be dealt with properly.
John

 

[tjhdexter]

Well Tom, you can't be sure that the floor of the outhouse has any damp proof membrane down there.....it's possible to paint one on though, using Permagard products or similar.
Any timber needs to be pressure treated, maybe 50mm wide and a thickness to suit. The gaps there can be filled with Kingspan slab insulation.
On top of that you can use a waterproof chipboard (22mm) followed by laminate if you wish but any damp issues must be dealt with properly.
John

Thanks for the reply that's really helpful! Didn't realise I would have to damp proof the floor as well. Leads me on to other questions but not really for the wood work section. I will bare all of this in mind!

 

[Burnerman]

No probs Tom.....the thing is, you can get water vapour coming through the floor which would normally dissipate without you knowing. Trap it and you get a musty smell so you need to seal it first. Permagard products form a sort of plastic coating across the concrete that keep damp at bay.
John

 

[tjhdexter]

No probs Tom.....the thing is, you can get water vapour coming through the floor which would normally dissipate without you knowing. Trap it and you get a musty smell so you need to seal it first. Permagard products form a sort of plastic coating across the concrete that keep damp at bay.
John

Yeah that makes sense I'll definitely give it a coat of the paint-on membrane. Another question is do you have any advice for fixing the timber together? More precisely on the inside of the frame. I know what one should look like just not sure how to fix the wood together. Thanks again.

 

[Burnerman]

It's best to construct a frame that goes right around the inside of the room, and at that point you can instal cross pieces - joists if you like - and the spacing of these depends on the final flooring you decide upon. Any joins in the flooring should rest on a joist to prevent bounce.
Any timber should be screwed down to the concrete floor...you don't need Rawplugs these days, there are special screws available which will go straight into concrete floor providing the correct size hole is drilled.
You'll need a SDS hammer drill to do this, of course!
There's no real need to joint the floor timbers together, screws forced in at an angle will do fine.
Food for thought?
John

 

[foxhole]

I would use ply as chipboard is only available water resistant , not water proof and have seen it fail quite often. I would screw frame to wall and not thru floor which would breach the damp coarse.

 

[Burnerman]

If you don't fix to the floor you can expect some bounce......after I'd drilled the pilot holes I removed the joists and recovered them with Evercryl.
I've found some coated weyroc (22) that I haven't come across before....it seems to have a plastic coating which is tough as hell. Obviously it depends on state of the OP's outbuilding, but I'd take a really good look at the door at the same time.
John

 

[foxhole]

I sit timber on floor , bit of adhesive, no bounce.

 

[tjhdexter]

The outhouse is in generally good condition but obviously need some TLC. Can get quite damp and cold in there but I wouldn't say it gets wet in there.

 

[Burnerman]

Before you do anything Tom, make sure the roof is in good nick.....is it flat and felted, perchance?
John

 

[tjhdexter]

Before you do anything Tom, make sure the roof is in good nick.....is it flat and felted, perchance?
John

No John it's neither unfortunately. I already have some waterproofing liquid in a tin (I'm guessing it's quite thick in consistency) which was bought by my father as there is a section of the roof by the doorway to the outhouse from the kitchen that leaks some times. Don't know much about it or how to apply it, though. The roof is slanted and not sure how to describe it but it looks like corrugated metal.