Patching and Plastering - Lath/plaster vs drywall and mold...

Out of curiosity is a lath and plaster wall more or less likely to suffer mold damage than sheetrock drywall?

It appears most of our home is lath and plaster circa '55 and we have noticed some minor mold growth in one room. Trying to guage how bad that could be behind the surface.

I would say mold for the sheetrock is actually more damaging...by virtue of the sheetrock paper. Plaster is like cement.

Is your mold behind a bed or furniture that is right up against a wall?... because that is common because heated room air can't circulate... and if you have any insulation (lack of) issue, that fact will locate this problem and cause it to mold (white froth) and/or mildew (black). Bleach will kill/make it disappear all by itself without you even rubbing on it, on the surface. But try to find the cause, like if it is a leak or condenstion due to what I said in the beginning.

We live in a brick Victorian house, which of course is all plaster, and here were our two issues with mold: First, we had some mold in the bedroom on the wallpaper...we didn't know what was going on, until we realized that the blocked gutter was leaking onto the wall, which in turn had a small hole in the mortar, which caused the wall to be damp and grow mold. Cleaned the gutter, filled the hole, sprayed some bleach on the mold, problem solved. The other, bigger issue was the bathroom. It had mold everywhere because of lack of ventilation. When we renovated the bathroom, we gutted it....and the mold was only on the surface. The lath and the studs were dry and mold free. Hope that makes you feel better!

Plaster is MUCH better regarding mold, or so I have read. Sheetrock will hold the moisture for too long, and that is when the mold comes into play. Cured plaster should not be very absorbent at all.