Hi,
Is it worth adding external wall insulation over the outside of a (presumed uninsulated) cavity wall on the ground floor only?
The house is extended on three sides and one of these is the garage (wall inside garage is the original render). Inside are the two rooms we spend most time in, so I wonder if this is low hanging fruit for insulation.
There's plenty of room to put up 2-300mm of mineral wool with a stud wall but I'm not sure whether this will be worthwhile - will heat from the inner leaf convect rapidly up the cavity anyway? Will the fact that the first floor is not insulated exteriorly just suck the heat up out of the lower masonry?
I haven't been able to access the top of the cavity due to the strange roof construction (last foot of the ceilings in the 1st floor are pitched, so can't inspect from the loft) but I assume it's open, and there's no evidence of cavity insulation having been applied in the past.
The house is extended on two more sides so I assume this is because CWI would put some rooms outside the thermal envelope, but that's another story...
The alternative is to insulate internally, but the decoration is to a good standard and it introduces all that condensation worry.
Welcome any input on what's worth doing!
cheers,
Dave
Is it worth adding external wall insulation over the outside of a (presumed uninsulated) cavity wall on the ground floor only?
The house is extended on three sides and one of these is the garage (wall inside garage is the original render). Inside are the two rooms we spend most time in, so I wonder if this is low hanging fruit for insulation.
There's plenty of room to put up 2-300mm of mineral wool with a stud wall but I'm not sure whether this will be worthwhile - will heat from the inner leaf convect rapidly up the cavity anyway? Will the fact that the first floor is not insulated exteriorly just suck the heat up out of the lower masonry?
I haven't been able to access the top of the cavity due to the strange roof construction (last foot of the ceilings in the 1st floor are pitched, so can't inspect from the loft) but I assume it's open, and there's no evidence of cavity insulation having been applied in the past.
The house is extended on two more sides so I assume this is because CWI would put some rooms outside the thermal envelope, but that's another story...
The alternative is to insulate internally, but the decoration is to a good standard and it introduces all that condensation worry.
Welcome any input on what's worth doing!
cheers,
Dave
