framing floor

[bluebaron]

Ok in consideration to the points above and also chatting to a builder mate of mine I'm going to lay two courses of bricks and mortar my DPC/Wallplate to that.
I'll then build my studwork of that and fill the void with DPM/100mm insulation and 22mm chipboard T&G flooring. Ill lap the DPM up over the wall plate and then start my stud walls from there.

If it hadn't been for the concrete already in place I would have build a floor joist structure and raised it up on either concrete blocks or Piles.

Woody mentioned the use of noggins but I can't see the benefit of this if the insulation is tight to the walls and the flooring is glued together? Perhaps you could enlighten me?

Thanks for help, ill post some photos in a few weeks when i've started.

 

[^woody^]

I'm struggling to see the point of laying bricks?

DPMs should not lap over wallplates or any timber.

Noggins stop joist flexing vertically, insulation does not.

If you look at many of the garage conversion threads in the building section, they have examples of how to build a floor off an existing slab.

 

[bluebaron]

Hmmm I thought the whole point of this was to have no joists, so how will they flex?

im just trying to keep the timber off the ground and a strip of dpc just isn’t my going to cut it IMO.

 

[Deleted member 174758]

I was trying to find a solution for the floor which maximised the insulation and minimised the cost...

 

[bluebaron]

I'm struggling to see the point of laying bricks?

DPMs should not lap over wallplates or any timber.

Noggins stop joist flexing vertically, insulation does not.

If you look at many of the garage conversion threads in the building section, they have examples of how to build a floor off an existing slab.

I'm not getting much traction on this. all the threads i've found involve building a shed on a slab of the same size. can't find one about building of an oversized one. Ive outlined some costs and think the building of a joist system on concrete blocks on the slab seems cheapest but no-one seems to offer an opinion?

 

[Deleted member 174758]

Is it the cheapest, though? You still need to get insulation under the sub-floor, otherwise the building will be like a fridge in winter. No matter how you do it there is a need to get a DPM between the concrete or the bricks and the timber because even treated timber is hygroscopic to an extent and will wick-up moisture from any concrete or brickwork beneath it which is in contact with the ground unless it is protected by a DPM. I think part of the issue is that you are thinking of this as a glorified shed, but in reality it is a living space, and to be a living space above all else it needs insulation and to be dry. Otherwise your "customer" might as well be working in a garden shed.

Good luck with whatever you build

 

[^woody^]

Construction is construction whether its a shed/summerhouse/room or whatever.

The same principles of a firm foundation to stop movement and a suitable means of damp prevention apply, and the only difference is in the degree and detail. Likewise for the use of the building in terms of internal comfort - ie insulation, ventilation, light etc.

So whether you use the existing base to build off, or as a sub-base for new base supports is just a matter of preference and then detailing. Whether its cost effective to do any such base in timber or blocks/bricks is just one of costing, but with the awareness of any knock-one costs or implications.

So, TBH, it should be relatively simple, you've got what two, three options? Each will achieve the same required result. And as you have already got a base, then it should be even simpler to decide.

 

[bluebaron]

thanks guys, was probably overthinking it, i've gone with the floating floor.