Attic Conversion in Double Hip Roof

TimHorton

Have an attic with 700 sq ft of usable space , At one end I want to create a small office for starters. Its a double hip roof and the hip timber is making the framing quite awkward , What is the best way to deal with it ?

mickdw

TimHorton wrote: »

Have an attic with 700 sq ft of usable space , At one end I want to create a small office for starters. Its a double hip roof and the hip timber is making the framing quite awkward , What is the best way to deal with it ?

Do you mean the way it sticks down further than the rest if the timber?

TimHorton

mickdw wrote: »

Do you mean the way it sticks down further than the rest if the timber?

Exactly - I do not want it exposed , I am looking for suggestions on how to insulate/frame around it.

mickdw

TimHorton wrote: »

Exactly - I do not want it exposed , I am looking for suggestions on how to insulate/frame around it.

Some will actually slab around that shape giving a clean enough finish but takes abit of work as it needs to be perfect.
You could counterbatten the rafters - will allow you to install extra insulation thereby hiding that hip rafter. Something like 2 x 2 battens would work.
Insulated slab would also possibly hide it.

jack of all

Counter batten it and introduce an air tight membrane while you're at, the void created by the battens will create an ideal service zone for electrical and allow you to maintain air tightness. You'll need to think about insulation and ventilation of the roof space in the pitched ceiling section though, so tread carefully.

sydthebeat

Looks like 5 x 2 rafters (125 x 44)

By the time you properly insulate, maintaining a 2" (50mm) vent gap.... You won't see that hip rafter at all.

I'd suggest 75mm board between the existing rafters and a 62.5 insulated plasterboard under. That would hide the hip.

Calahonda52

The hip rafter makes continuous roof space ventilation a bit tricky.
What material is the roofing felt

TimHorton

sydthebeat wrote: »

Looks like 5 x 2 rafters (125 x 44)

By the time you properly insulate, maintaining a 2" (50mm) vent gap.... You won't see that hip rafter at all.

I'd suggest 75mm board between the existing rafters and a 62.5 insulated plasterboard under. That would hide the hip.

Was looking at this option, 62.5 will come up short of the hip, Maybe if I counter batten this will bring me clear of the hip and introduce service area - I will also maintain 50mm vent air gap. Would this be possible, I would also like add Air Tight membrance on the warm side of the 75mm board. Is this recommended?

TimHorton

Calahonda52 wrote: »

The hip rafter makes continuous roof space ventilation a bit tricky.
What material is the roofing felt

If I leave the 50 mm Air Gap I presume I am ok? , The house was built about 15 years ago so I assume its breathable felt.

Calahonda52

TimHorton wrote: »

If I leave the 50 mm Air Gap I presume I am ok? , The house was built about 15 years ago so I assume its breathable felt.

the 50mm is between the felt and the rigid between the rafters which will be the exact shape so airtight