Attic insulation

mccarthy.087

Hi everyone, just looking from advice from anyone who has maybe converted an attic into a liveable space recently.

Aporox 3 years ago I got my attic roof rafters spray foamed and now I’m getting around to start convert it to a livable space. My question is what thickness of insulated plasterboard should I go with on top of the spray foam. Is a 30mil insulation plus 12mm plasterboard sufficient or should I go thicker?
I was planning on putting 70mm PIR in the knee wall with the insulated plasterboard on top of that also.

MicktheMan

Where is your air tight barrier & what is your airtightness strategy?

Calahonda52

Is there a ventilation baffle behind the spray foam?
what type was it, open or closed cell?
is it done from eave to eave including the ridge board?
what happening at the eaves?
whats the plan for the ceilings behind the knee walls?
whats the plan for stopping wind passing under the attic floor and chilling the ceiling below?

mccarthy.087

MicktheMan wrote: »

Where is your air tight barrier & what is your airtightness strategy?

WelI was just going to run with using the spray foam along with the Foiled backed PIR board taped at every joint as my air barrier. I already have the ceiling below taped with an air tightness membrane.

Calahonda52

How are you meeting the Fire regs?

mccarthy.087

Calahonda52 wrote: »

How are you meeting the Fire regs?

Have roof window in each of the rooms in the attic which meet fire regs height and width opening. Have a fully wired fire alarm system and have my stairs positioned directly inside my front door provide the quickest access to the outside.

Calahonda52

mccarthy.087 wrote: »

Have roof window in each of the rooms in the attic which meet fire regs height and width opening. Have a fully wired fire alarm system and have my stairs positioned directly inside my front door provide the quickest access to the outside.

2 or 3 storey?

mccarthy.087

Calahonda52 wrote: »

2 or 3 storey?

Bungalow