Garage conversion process

[marchhare101]

Hi, im an amateur at this and would like to know if my proposed plan of action is in the right order etc.



I have an attached single garage with a flat roof and a concrete floor. The two outside walls are single skin brick. I will be getting a builder in to create a door into the house and also to brick up the side door and front of garage, leaving space for a window. Also will get a plasterer. The garage is two courses below the house. I will be doing this with regs.





Create doorway from house

First fix electrics



Floor

Place DPM on to garage floor

Fix joist hangers to walls and place joists (this method will be used to level the floor as i think the concrete slab is sloped).

Place celotex or similar between joists.

Lay T&G chipboard up to dpm which will run up the wall a couple of feet from the floor.



Walls on single leaf sides

Apply vapor barrier across wall

Fix base plate to chipboard floor attaching through floor joists.

Fix head plate to roof joists.

Fix studs at 400mm intervals.

Fix noggins.

Place celotex between studs

Plasterboard

Plaster



Walls house sides

Dot and Dab and attach plasterboard's

Plaster



Ceiling

Fill void with rockwool insulation

Plasterboard

Plaster



Questions. Do i screw the chipboard to the joists?

Does the DPM on the wall sit between the brick and stud wall or between stud wall and plasterboard?

At what stage do i have front of garage bricked up. Would it make sense to have that done before anything?

How does the wall DPM attach/stay in place?

At what stage do i have second fix electrics done?



Thanks in advance.

 

[noseall]

You forgot about the roof! This will need upgrading insulation wise also.

Timber floor may need venting. A better option would be to lay down insulation sheets then screed.

Leave bricking up the garage door as long as possible as this is an ideal access point. You can still do the knock through as long as you secure t'uther side with some ply etc.

First fix electrics after structural fixings/alterations.

 

[marchhare101]

Thanks for the advice. I will be doing a joist floor as a screed floor is probably beyond my capabilities. Thanks.

 

[mc99]

Glad I found this post. I have a similar project on the go.

I can echo your questions and try to advise on one point. Let's hope we get some more advice

Fixing stud to "floor"

Your plan to secure studwork to joists through floor sounds good. Stable and above the DPM under your joists. I have building regs drawings which specify DPM over the existing concrete floor, insulation and chipboard. My question is; do I fix studwork to the concrete floor through the DPM or do I build the stud on top of chipboard floor and try and secure through to the concrete below?

Vapour barrier

My drawings specify a breathable membrane against the wall. Stops water coming through the brickwork (in the unlikely event) but lets moisture out through the walls to avoid condensation.

DPM

Pretty sure the DPM goes over the existing concrete floor then up to the DPC in your outer wall. I have seen DPM joining tape.

Comments anyone ? Thanks

 

[marchhare101]

Had an interesting conversation with my BCO over the phone. He said i didn't need a vapor barrier on the stud wall just use bitumen paint. Also under the floor joists there was no need for a dpm. All i need is a dpc under each joist.
The only thing im concerned about is the roof. The BCO said i will need a warm flat roof. Now im not sure if this means replacing the roof or not.