Insulation plasterboard

[Ssan diy]

I was thinking to dot and dab the insulation board on to my wall in my extension but my walls are already plastered but i need more insulation as its freezing out there in the winter

 

[phatboy]

If your wall is flat you could mechanically fix insulated plasterboard to the existing wall, would save a few mm compared to dot'n'dab.

I assume the extension is old? Are you sure the roof is adequately insulated? A lot more heat is lost via the roof than the walls

 

[Ssan diy]

The cieling is t&g at the moment i was going to put some insulation in the joists and just plasterboard n skim it

 

[phatboy]

Is that the inner skin of a flat roof? There lies your biggest heat loss if so! 100mm or more Celotex or similar would resolve it. If you have the headroom go over with 15mm insulated plasterboard too to reduce any cold spots.

Add what you can to the walls, but even a little will help a lot.

 

[Ssan diy]

Yhh i was going to put the loft roll up there

 

[Ssan diy]

When u say mechanically fix the plasterboard to the walls you mean the nail anchors