roof insulating

[andy100]

Someone has converted our loft by nailing plaster board to the roof joists etc and skimming it, not a bad job but for one thing they have not used any insulation under the plaster board.
I tried pushing sheets of polystyrene up from the bottom where there was access that was a waste of time, is it possible to inject the cavity with cavity wall insulation and can you do this yourself??.

ps the roof is not felted so would I end up with white foam oozing from all of my orifices.

Many thanks

Andy

 

[masona]

If this was done by a builder with a building permission plus drawing then they have broken the building regulation as the building inspector would've not passed it.

You cannot inject the cavity with cavity wall insulation as you must have 50mm air-flow gap at the back of the rafters.

As you said your roof is not felted so it must fairly old,so if you are thinking of replacing the roof tiles then that the time to put in insulation from the outside unless you rip off the plasterboards from inside and start again.

The only other way I can think off is batten out in front your plasterboards again with insulation then new plasterboards.

Sorry, I've not given you good news.

 

[andy100]

Thanks Masona

I think the loft conversion was done over twenty years ago.
You have confirmed what I suspected, the thought of replacing all the plaster board doesn't appeal to me somehow. I have fitted a radiator with thermostatic valve on it in the loft this at least takes the chill of it.

Many thanks

Andy

 

[masona]

Just has another thought,

You could use foam insulation wallpaper,makes the wall warm but must leave to dry at least 48hrs before putting wallpaper over it.

 

[skellem]

I used to build wooden houses in Scotland a few years back. What we used was recycled newspaper. It is shredded, treated and then pressed into a large block. What you have to do is use a special machine that pumps the newspaper through a long tube and into the cavity. It's very good because it's more eco friendly and you also only need about a 50mm hole at the top of the cavity to pump the stuff in. Beware, it's very messy and dusty!

 

[masona]

The only problem I can see here is,you will block the airflow as the timber need to breathe.

 

[skellem]

True, it would have to be some kind of rockwool insulation layed on the back of the board