How best to insulate an attic room

Recently moved into our home and are doing up the original attic room. I am unsure as the best way to insulate this area? The house is a mid terrace and the room Measurements are approx 5.5m x 6m with pitched roof that is 3m high at the apex sloping down to 1.35m at room edge. Am i best to insulate under the attic floor in between the joists and also try to insulate the sloping ceilings or just do one of these. Im not sure what products would be available for insulating the ceilings, but have heard that there is a plasterboard called kingspan which contains insulation. Any suggestions as to what would be the best optionts would be much appreciated

Reply to
sav
Loading thread data ...

Having just insulated a Victorian attic, I'll tell you what I wish I'd done from the start. Rip down the ceiling. Rip down any walls where you don't have comfortable access from the other side. Put 50mm Celotex between rafters, and rockwool between joists on the walls (if you want to keep the cost down). Plasterboard and skim.

I sort of did this but tried to retain as much of the original plaster as possible by feeding the insulation in from all kinds of crazy angles. I should have bitten the bullet, but the mess is just so awful that you really must do the whole thing in a day so you can clear up just the once. Doing it in dribs and drabs as I did, you spend an hour knocking off the plaster and two hours clearing up. Then another two hours clearing up yourself, your tools, your vehicle, your own house. Never again, even for family!

If you can afford to lose space on the inside, it's obviously much easier, but the impact on doors and window openings has to be considered. Maybe you don't have lath and plaster to contend with. Taking down PB would have been a doddle in comparison

Reply to
Stuart Noble

If you are trying to make the attic room warmer then insulating under the floor will not help you much (it may cut down noise transfer with the room below though)

Kingspan is a brand for many different types of rigid insulating board products - typically made from PIR Foam which is a very effective insulator. They also do a version pre-bonded to plasterboard (and ply etc). Celotex is another big name that does much the same. You can find alternative suppliers however that can be a good deal cheaper. Have a look at their web sites for more info. Also see:

formatting link
do the underside of a roof, you can partially fill the gap between the rafters, and then do another layer under, followed by plasterboard. If your tiles have sarking (i.e. tilers felt) behind them then you need to make sure that you leave a space behind the insulation that can be vented to the outside to keep the roof timbers in good order. Otherwise condensation can form in the space that will rot the wood. Fitting soffit vents can help as can either ridge vents or just cutting away a strip of sarking near the apex of the roof.

Here is how I did mine:

formatting link

Reply to
John Rumm

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.