Condensation/Frost on foundation

[leftylespaul]

Hi all,

I recently developed the basement of my new home and just before the plastering stage, I noticed frost and condensation on the warm side of the foundation. I'm afraid to plaster and paint the walls as I expect mould could grow. I attached 1 inch ridgid foam and also built and insulated an additional wall with traditional insulation. The ridgid foam has signs of condensation and the pink insulation is damp in places. Can anyone provide insight into my dellima? I cannot see any cracks and there appears to be a tight seal between the sil plate/gasket and the foundation.

 

[noseall]

I'm pretty sure your building codes will be different from ours in the UK.

However, cold is cold no matter what.

1" of insulation does seem very lean and would not satisfy building codes this side of the pond.

Also, basements are naturally damp places so specific treatment is required for these locations. To bring these spaces up to spec' the work is both involved and expensive.

Are you a Gibson fan?

 

[roboughton]

Having wathced that Mike Holmes guy fix many a dodge basement in Canada he alwats seemed to tank the basments but I think you need to look up some advice from guys your side on the correct codes. That Mike guy was always going on about how the Canadian builders were just trying to rip people off by not installing the correct things.

 

[JohnD]

it sounds to me (assuming the house is already built and you are just finishing the bare basement) that warm moist air from the house has met the cold walls and caused condensation and damp.

I don't see how you would get actual frost on the inside walls of a basement already. Are the inside surfaces below 32F?

You will have to dry it out. If the walls are very cold that will be difficult, but a dehumidifier eft running with all doors and windows shut wil do it, and will also deliver some dry heat. Once you have got the walls dry, you can reinsulate and board the walls. You wil need an impermeable vapour barrier to prevent the warm moit air from the room being able to touch the cold walls. Rigid foam insulation resists damp better than pink glass wool. You will probably need to strip off and discard any wet insulation.

Canadian materials, building techniques, construction codes and climate are very different from the UK (this is a UK website)

 

[leftylespaul]

Thanks for the reply guys.

Yes, its a new house with an unfinished basement and yes, it was approx 19F here during the past few days--very cold.

The frost is only at the top of the foundation where it meets the sil. I guess the rest of the foundation is under the freezing point.The funny thing is that there is a section of the same wall in a laundry area that has no signs of frost whatsoever.