Hello. Looking for some advice. Recently moved into a granite home built in 1888.
The lady I bought off told me the attic had been insulated during her time but never got the chance to look until moving in.
Having stuck my head in, there is shrivelled up rockwool over parts of the joists max 100/50mm thick (A on the diagram). I wanted to see what others on the forum with more experience would do.
The Joists (A) are 42cm wide and 22cm deep and the rafters (B) are 17cm deep and 40cm wide. The walls (C) of the internal attic room are old lath and plaster.
I have no issues getting my hands dirty. Rather then removing and replacing the rockwool with new and thicker amounts would I be best the remove the walls of the attic room and insulate with 120mm PIR board between the rafters and 25mm under them to create a cold roof?
I have access through a friend to cheap PIR boards which is why I am leaning that way.
Then it would allow me to plasterboard where the old internal walls were with a comprehensive insulation of the whole roof?
Any advice on alternatives welcomed. Thanks in advance.
