Basement walls have "odd" coating on them (///AG)

SFX Group · 11-20-2010, 10:24 PM

Hi all

We have a house (found calendars of 1943 on the support beams in the basement, this is probs its build age) its concrete pour, very flat floors, no cracks, very well built.

However i notice on the basement walls there’s a very white covering, some places it falls off like a chalk based covering, others it still sticks, it’s around 1-2mm deep (1/25th = 2/25 inch deep), what is this?

Looks like an original vapour barrier maybe?

If a brush is passed over it and some will come over (due to age it appears), the walls are cold but not damp, however when touching this stuff it is nowhere near as cold as the wall that’s uncovered.

Be nice to know what this is. should i remove it all or just brush what’s loose then put over FOAMULAR (was going to use 0.5inch then 2inch studs and fill these).

What R value am i looking at hitting when doing the basement walls? The 0.5inch flat FOAMULAR is 2.5R then add other polystyrene between the studs

**oh'mike** · 11-21-2010, 07:14 AM

Often the old concrete walls were white washed with either a lime or white portland cement.

I'll let a local guide you on insulation--you are in a colder climate than me---