Additional loft insulation between rafters or qulit insulation on underside of roof

simcla

I live in a Victorian terraced house with some rockwool insulation between rafters in an unboarded loft. I want to board some of the loft and I may convert the loft at some point in the future. Should I put additional rockwool down or fit a high performance quilt insulation under the existing slate roof? ie the YBS qulit insulation

bookduck

simcla wrote: »

....under the existing slate roof?

So you don't mean the carpet type fiber-galss type matting, but like a foam spray, so what do you do when the roof leaks, how do you find that cracked tile?

You might want something on the floor for sound insulation as not to hear people walking above you.

robv_3

Would advise you to do lots of research before using any foil insulation. Its my understanding a number of councils building controls have stopped accepting them as they believe it does not meet the manufactures performance ratings( R/U values). A number of them fail the British Standard (BS) tests so the manufactures figures can not be confirmed officially. The manufactures state its because the BS tests are out of date and not the fault of there products.

Most joists in lofts are not designed to take the extra weight when storing heavy stuff in the loft. Expect to see cracks appear in the ceiling etc unless you build additional support. If its only light stuff the easiest and best performance way is to lay kingspan/celotex installation directly on the joists and place chipboard on top.

03022242

agree, do not use any type of multifoils, theyre not worth the bother