Refurbishing a 1900s house that has been empty since 2004.
The roof is pitched slate over batten ( and that's it!). There is no loft insulation at all, so am going to fill in-between ceiling joist and over with 300mm of loft insulation. However the external walls have an open 50mm cavity.
Do I need cover over the cavity with the loft insulation provided it will leave a 25mm gap between top of insulation and roof, or should I cover over/fill the top of the cavity with 50mm PIR?
The internal side of the external walls will all be fitted with 72.5mm of insulated plasterboard if that makes any difference.
Thanks in advance for any help.
Jo
The roof is pitched slate over batten ( and that's it!). There is no loft insulation at all, so am going to fill in-between ceiling joist and over with 300mm of loft insulation. However the external walls have an open 50mm cavity.
Do I need cover over the cavity with the loft insulation provided it will leave a 25mm gap between top of insulation and roof, or should I cover over/fill the top of the cavity with 50mm PIR?
The internal side of the external walls will all be fitted with 72.5mm of insulated plasterboard if that makes any difference.
Thanks in advance for any help.
Jo
