General advice for garage project

[dmills27]

Hi all,
Was hoping to get some advice on a project I am undertaking whilst I have the time. I have a detached garage that I am planing on converting to 3 separate rooms (two home offices, and storage room) I want it all to be insulated as best as possible and will be adding some IR electric heaters.
I need a couple of pointers to get going.

floor - planning on a floating floor (on top of dpm) with 50mm jablite like this : https://www.diy.com/departments/jab...ation-board-l-2-4m-w-1-2m-t-50mm/26826_BQ.prd

will this be ok to simply lay 22mm chipboard on top? Worried about the rigidity/ compression. (The slab is level)

Walls - I am going to use timber studding with insulation for sound and thermal. Shall I use 3 x 2 or 4 x 2? What’s recommended?

also is it best to build the walls, and then lay the floor, and if so if I drill into the concrete through DPM is this ok?

Or do I attach the walls to the floating floor (worried walls will move if floor moves this way??)

thanks in advance!

 

[Deleted member 174758]

Do the walls first, then the floor.

Jabolite Jabfloor is used in screeded flooring so it should be OK to have a chipboard board floated on top providing you glue the joints (D4 flooring or PVA adhesive, NOT Gorilla or polyurethane glue). I'd suggest getting a P5 (moisture resistant) board if possible

Stud wall can go directly onto DPM and fixed through. If you are concerned about water migration you could always run a couple of beads of silicone sealant along the bottom of the frames before raising them into place to give additional sealing. TBH, though, I wouldn't bother about it.

For maximum soundproofing the thicker the better. Mineral wool slab (as opposed to roll) is effective at a reasonable price. I'd also consider using sound block plasterboard (the lilac coloured board) instead of ordinary grey boards. Ideally you want an air gap between the outside walls and the back of the insulation/frames

Have you considered what you are going to do about the ceiling? If this needs boarding that job should ideally be done before the walls go in