Very basic design question - from 'the other side'.

[chris watkins]

It's just the same for floors (& ceilings) is it not Ermi, that's why the polythene membrane has to go into the underfloor construction layers normally before the heating goes in.

 

[bennygas]

So the good news is mike, ermi has diagnosed your problem with no call out charge, the bad news is it sounds your gonna have to spend a small fortune doing what he said, all so as you can have that L-shaped sofa.....can't talk her round to having a few bean bags and a wood burner? Never done anything with MHVR, but is it possible such a machine could change the humidity characteristics such that the temperature gradient and dew point don't intersect? (I take it your walls aren't cavity, but solid - presumably temperature gradient would be more linear/nearer to single gradient).

 

[Ermintrude]

Be a very dry cold house

 

[bennygas]

Why cold?

 

[Best]

Outside walls on non cavity houses worth considering having stud walls built in front of them if you can afford to lose a few inches of room.
Even 2x2" strong framework or bigger will do. Don't have it touching old wall & insulate the stud.

 

[Ermintrude]

Why cold?

Humidity would need to be low or if house and outside close in temp dew pt on outside face of wall. Temp grade need to be low?

 

[Ermintrude]

What was wrong with my idea then?

Dosnt shift enough moisture . If you want to eliminate it in wall need a 300kw dehumidifier ! All that is is a pump with some carbon and poly filters

 

[bennygas]

Surely there's a bit more to em than that? In the blurb I've seen, reducing condensation is sold as one of the benefits. I'd wanna be sure there wasn't a damp or water ingress issue partly cos the problem appears localised before going to the trouble of external insulating render etc. quite like the idea of the render though.

 

[Ermintrude]

Yep garden walls are brilliant for this also down pipes discharging against house at bottom. Or concrete / impermeable footways built against house. When