Solid Wall Outrigger Conversion

[S1066]

Hello,

I’m after some advice please… I have a solid wall construction outrigger, previously used as a utility room but due to lack of ventilation has formed mould and damp internally.

My plan is to turn this into a downstairs toilet (same as the room directly above), I am going to create stud walls, backed with a breather membrane, filled with foiled backed insulation and finished with plasterboard. I also need to raise the floor height to line up with the existing house.

- Firstly am I ok just wiping down the walls with vinegar before commencing work, or do I need to strip it completely?

- Any better ideas for construction method?

- I assume it’s best to raise the floor and mount the studs directly to the new floor?

- Any ideas how to run services through it?

- How do I build around the window, or is it best just to build up to it?

Many Thanks

 

[noseall]

Hello,

I’m after some advice please… I have a solid wall construction outrigger, previously used as a utility room but due to lack of ventilation has formed mould and damp internally.

My plan is to turn this into a downstairs toilet (same as the room directly above), I am going to create stud walls, backed with a breather membrane, filled with foiled backed insulation and finished with plasterboard. I also need to raise the floor height to line up with the existing house.

- Firstly am I ok just wiping down the walls with vinegar before commencing work, or do I need to strip it completely?

- Any better ideas for construction method?

- I assume it’s best to raise the floor and mount the studs directly to the new floor?

- Any ideas how to run services through it?

- How do I build around the window, or is it best just to build up to it?

Many Thanks

line DPM on the floor and lap up the walls.

Insulate and screed the floor.

line DPM up the walls.

Trap 50mm PIR insulation against the walls with a 50mm x 50mm stud frame.

Fill the stud frame with PIR.

Fix Duplex boards etc.

 

[S1066]

line DPM on the floor and lap up the walls.

Insulate and screed the floor.

line DPM up the walls.

Trap 50mm PIR insulation against the walls with a 50mm x 50mm stud frame.

Fill the stud frame with PIR.

Fix Duplex boards etc.

Thank you @noseall, top tips and certainly seems less work.

So it’s ok to an attach PIR directly to the wall as long as it’s over a breather membrane/DPM? I had in my head I needed a stud wall sitting off the face, acting as a type of cavity I guess?!

Cheers

 

[noseall]

Thank you @noseall, top tips and certainly seems less work.

So it’s ok to an attach PIR directly to the wall as long as it’s over a breather membrane/DPM? I had in my head I needed a stud wall sitting off the face, acting as a type of cavity I guess?!

Cheers

No need to fix the insulation - just trap it in.
No air gaps needed with the above method. In fact, foam any gaps and foil tape any inso' joints.

 

[S1066]

Brilliant thanks again @noseall.

Just to clarify - breather membrane against the inner brickwork, 50mm PIR (tape joints), build a stud against it (fixed to the floor and ceiling I presume), fill with PIR and finish with plasterboard. If bringing water through the boards do I just seal around the pipe work? I’ve seen gaskets that slip over pipes and tape to the insulation - is that overkill?

Floor - build up with grano, DPM lapped up onto new wall, PIR then lay boards on top (like a floating floor)?

 

[S1066]

Also how to I approach the window reveals?

 

[noseall]

Also how to I approach the window reveals?

Up to you really. You'd frame the studs out so that the header, sides and sill, mimic the masonry aperture size, then add plasterboard - which can be dabbed foamed or mechanically fixed to the masonry. It looks as though there could be enough meat on those frames to allow a wee bit of insulated plasterboard to be fitted into the reveals.