On (the inside of) an external wall, is there much benefit to foam backed boards? Construction is stone in places, brick in others.
What about party walls?
Generally speaking of course.
On (the inside of) an external wall, is there much benefit to foam backed boards? Construction is stone in places, brick in others.
What about party walls?
Generally speaking of course.
What are the wall constructions?
Any insulation already in them?
Jim K
yes. If the stone has no other insulation.
Probably not, since the temperature differential across them will be small.
Yes, but beware interstitial condensation (with any form of internal insulation).
Short version: The air inside a house usually has more water vapour (measured in grams / cubic meter) than the air outside. The vapour level through the thickness of the wall will gradually fall to the level outside. If you insulate inside, the temperature will fall steeply to the outside level, so the temperature may fall below the dew-point in the middle of the wall.
Solutions are: A really vapour-tight vapour barrier. Using an insulation that can wick the condensate away.
Unlikely to be worth it. The other side of the wall will be pretty warm anyway (and no wind on it).
/ Short version: The air inside a house usually has more water vapour (measured in grams / cubic meter) than the air outside. The vapour level through the thickness of the wall will gradually fall to the level outside. If you insulate inside, the temperature will fall steeply to the outside level, so the temperature may fall below the dew-point in the middle of the wall/q
And?.........
Jim K
... and you get condensation. Regular soaking in liquid water is damaging for most building materials (particularly wood and lime mortar.)
(I had mistakenly assumed that didn't need saying).
- show quoted text - ... and you get condensation. Regular soaking in liquid water is damaging for most building materials (particularly wood and lime mortar.)
(I had mistakenly assumed that didn't need saying). /q
Mmm I believe the jury is still out on all this.
France has, so I've read, internally insulated millions of houses with no apparent interstitial ill effects according to their equivalent of our BRE.
Jim K
not really
trivial to do
NT
/> Mmm I believe the jury is still out on all this.
not really
trivial to do
NT/q
Gee definitive stuff there...
Jim K
If the foam has a closed cell sructure it is not a problem. If it is air permeable, there may well be a problem. Many foams are aluiminium foil covered to prevent interstitial condensation.
/If the foam has a closed cell sructure it is not a problem. If it is air permeable, there may well be a problem. Many foams are aluiminium foil covered to prevent interstitial condensation/q
Indeed.
It's hard to imagine a habitable solid walled room that would not 'suffer' interstitial condensation according to the definitions promulgated here.
Jim K
Maybe you'd had a few too many when you (mis)read those 'definitions promulgated here.'
/Maybe you'd had a few too many when you (mis)read those 'definitions promulgated here.' /q
Er.., no dear....
Anything constructive to add today?
Jim K
I think its pretty much covered already. Troll on.
NT
/I think its pretty much covered already. Troll on.
NT /q
I'll take that as a 'no' then (once again).
Why do you bother posting? you don't add anything?
Who's the real troll?
Oh and f*ck off, feel better now?
Jim K
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