Q. A lot of us with older homes (100 years) are getting energy audits with recommendations to blow in cellulose into the empty exterior wall cavities. I have read that without a vapor barrier moisture can be trapped in the walls, leading to mold and wood decay. Do you have an opinion on this?
A. I think that what you have heard is mostly an old wives tale. Thousands of houses have had insulation blown in without incident, mostly because old houses are so leaky that there is little or no chance for water vapor to build up to cause the insulation to take on water. Even vinyl- and aluminum-sided houses don’t have the problem.
But in some cases, water vapor builds up in tight houses until it forces its way through the inside wall surface, the vapor barrier and insulation, hitting the back of the cool sheathing, then condenses into water which then goes through the sheathing and forces itself through siding, pushing the paint right off.
The vinyl siding people found a cure: Take off the siding, and install sheets of 3/8-inch-thick Styrofoam on the sheathing, and put the siding back on. The insulation keeps the sheathing warm enough to prevent condensation of the water vapor. There might always be water vapor in the insulation, but it cannot condense because the sheathing is warm. It’s the only cure.
The ongoing problem is evident from the dampness in basements and the musty smell, caused by mold. The cure is simple: ventilate all cellars and basements.
Q. My 1955 Cape style house has a brick front, with the bricks are pulling away from the wall. My father, who discovered the problem, said the brick will likely need to be replaced. Is it possible to take off the brick and just put siding on the sheathing?
A. Taking off the brick is a given. The bricks were laid along the wall and secured to the sheathing by brick ties, aluminum or steel strips, with one end nailed on the wood sheathing and the other mortared into the brick. The ties in your house were either broken or never installed. I think it was the latter. Putting siding up instead of new bricks is unlikely to work well because the surface of the sheathing is not in the right place for siding. So, replace the brick. The best brick to use is a water-struck or tapestry brick. Go to a brick yard and ask the owner or a knowledgeable the salesperson which bricks would be best for your house.
My nonstandard height storm and screen door needs replacement. Do you know if it is possible to cut off about 2 inches from the bottom of an aluminum storm door? Any other suggestions?
A. I don’t think you can trim an aluminum storm door, but since you imply that you haven’t bought the door yet, why not buy a wood storm and cut it to fit. The Brosco catalog, where you can see such doors, says you can cut 2½ inches off the bottom, and some off sides if necessary. The wood door can be stained or painted and in my opinion works and looks better than any aluminum one. The only alternative: Rebuild the entrance to accommodate the new door.