we just put a roof on the house this summer and new siding as well. The upstairs room is unheated and we did not insulate or cover the walls (no sheetrock or wall panel of any type). We are in Portland, Oregon and this has been an exceptionally wet winter and cold as well. Moisture has been collecting on the tips of the roofing nails that protrude through the osb decking and now we are seeing a large presence of mold on the under surface. Is this understandable in light of not heating or do we need to ventilate better or close the remaining air gaps that exist at joints of wall to roof sheathing? if we insulate are we merely going to trap the future condensation in the remaining space or will that solve the condensation problem? Thank you so much for your help and your time!

Travis,
Read ALL of my Condensation and Ventilation columns as fast as you can.

Thanks for your web site which has been very helpful. Here's my question: We are building a new home in Florida. It is not under roof yet and we are in the rainy season. What do we need to do to prevent mold until the house is sealed? Again, thanks.

Dear Tim,
My problem differs enough from most to require this email. I have built a port-e-chohere/deck using 2x10 beams (3 2x10 per beam). The builder did not use treated wood, but explained that quality paint would be as effective. Nevertheless, after mold ate the supports beams in three year I had to rebuild the supports. The actual decking material is in great condition, but the substructure supporting woods seem to have beem eaten. In some cases it was as if the cellulose had been eaten out of the wood. It was not gree, black, or damp... just brittle.

Three months after replacing the beams I noticed the nold growing again. Some is black and grows outward and react like a pollen on a flower, easily blowing into the envirobnment when touched. Another type grows from between two pieces of wood and llie a mushroom. I have used a product from Home Depot and that seemed to work for a month or two, but the mold returns. Oh yes, by the way, the home is on the Brazos river outside of Houston, so it almost always damp.

I suppose this is going to be a an ongoing concern that will require monthly treating of color/water 50/50 and then a mildecide. The problem is, the mildecides seem awfully expensive to have to use every month (the porte-chchrere sunstructure is about 26 x 20).

This is an exterior problem, so no health issue (unless the supports give way and people get hurt!).

By the way, tha e paint was Behr and I added extra over-the-counter mildew protection. Doesn;t seem to have helped much. The last place I cleaned the black powery milder from the paint came right off (only the pressure from a standard sprayer from a garden hose)

I value your suggestions.

Regards,
Dennis

I have a damp basement. The water is entering up through the floor. The walls are dry except where water has wicked up from the floor. Even when no water is visible, the worn paint patches effloresce.
We have a very high water table here.

I had a foundation company visit and look over the basement. He said my only problem was the size and depth of my sump pump - that the pump allowed water to rise until it touched the underside of the floor slab and then the water soaks up through the concrete.

A new sump dug, and a new pump with back up will cost me abou $2500.00. I will gladly pay this if it will fix the problem. It almost seems too simple. What is your take on this?

(There is no visible water around window wells or on walls. I have cleaned and repaired gutters, raised the ground level near the foundation to ensure a dro in grade away from the house, dug a swale to carry water from between houses into my front ditch)

Thanks

Phyllis

We have mold on the drywall in our basement. We are going to remove the wall board completely but I would like to kill the mold before we start tearing it out. Would spraying it with bleach do the trick?

I have mold growing behind a brick veneer. I have moisture barrior paper and weep holes. It is on a wall that had several appentics working on it, i amwondering if the cause couldcome form to much mortar being dropped behind the wall.What are your thoughts?