improving insulation and dormer refurb in an 80's house

[Tirglas_7]

Hi

we have just purchased a 1980's house with large front and rear dormers, and i'm hoping for some advice from the experts please.




were having quotes on getting the dormers done in epdm with new plastic cladding at the minute , but the quotes seem to vary wildly, with detail on whats being done a bit vague.

i have asked for improved insulation, but as the dormers are being done should i be specifying a certain standard to them? and what would be a good setup for improved insulation?

i've read up on cold/warm roofs. i take it the dormers will probably be cold roofs at the min? should i be requesting/should they be advising to convert to a warm roof?

where i can access the void in the eves i can see the rest of the roof is currently insulated using foam/polystyrene sheets/tiles. could this be further insulated by inserting rockwool or similar? or am i asking for condensation or other problems?




where the rest of the roof slopes at the ends inside the dormer bedrooms, and the flat portion of ceiling overhead between the two large purlins/beams that run the length of the top floor, could kingspan plasterboard be installed from underneath?
obviously this would decrease room space, but as the rooms are pretty big, if it is effective at improving insulation i could live with any losses.





thanks in advance, any other advice or recommendations welcome and appreciated

 

[noseall]

Your quotes will vary because the interpretation of work needed by each contractor will vary.

Have the renovations designed and specified by a techie bod as they will likely need to meet latest standards. The work needs to be carried out by experienced trades who are familiar with controlling the migration of moisture etc. There's more to just bunging in Celotex.

 

[Tirglas_7]

Many thanks for the reply.

By techie bod, are we talking an architect?

 

[noseall]

Many thanks for the reply.

By techie bod, are we talking an architect?

Architect would be overkill, but you get the gist. A technician would suffice.

 

[Tirglas_7]

Ah ok, this is sounding more complicated/expensive than I first thought. I'll have to do some more digging then:-/

 

[John D v2.0]

When you say it's insulated at the moment, that insulation is about as good at keeping the heat in as a coast would be tied around your waist.I think that insulation is just for show.
You could do wors than just supporting it properly and making sure no gaps.

 

[Tirglas_7]

Thanks for the reply

Do you think there is any benefit to overboarding using insulated plasterboard on top of the existing plasterboard?

Or should I bite the bullet, pull down all the plasterboard and install cellotex/kingspan between rafters/joists then fit new plasterboard?