Vent fans to the outside to keep cold air out of bathroom

Q. Do you have a bathroom fan that you like? I've got a late 1950s ranch. Two full baths back up to one another - both 8-by-8. We have not remodeled yet, but plan to this year.

I hoped to get the old one replaced now, though, as cold air from the attic is pouring into the house because of how poor the existing fan is.

It is NOT ducted anywhere and just exhausts to the attic, currently.

A. Do both bathrooms have fans? You mention only one fan. If both are discharging into the attic, they should be individually ducted to the outside.

The cold pouring in is due to the lack of adequate venting of the fan, not the fan itself.

Unless you feel that you can do it yourself, you should have a contractor install proper ducting to a gable wall, and I suggest that you use these instructions:

• Do not vent through a gable vent, a ridge vent, a soffit vent or through the roof in a cold climate.

• Install a 4-inch 90-degree PVC hub or an adjustable metal connector to the fan exhaust (if you use the PVC hub, you'll have to cut a short section of the recommended Schedule 10 or 20 PVC pipe to fit both into the hub and the bell-end of the pipe).

• Use Schedule 10 or 20 PVC drain pipe (4-inch diameter, 10-foot long with a bell-end).

• Connect the first section of pipe - bell-end facing the fan - to the short piece of pipe attached to the hub and, if needed, additional sections of pipe to a gable wall.

• Cut a 4-inch hole in the gable as low as possible in order to keep the pipe run as flat as possible and preferably with a slight slope to the outside by placing small wood blocks of decreasing thickness under each section of pipe.

• Connect the pipe to a hooded wall jack (avoid plastic louvered jacks as they have a tendency to break in the cold).

• Snug 4-inch thick fiberglass insulation to each side of the pipe and place another layer of insulation over the pipe to keep it as warm as possible for the length of the run.

That should do it without having to replace the fan if it is satisfactory otherwise. But if you feel that you need to replace it, get a whisper-quiet one in a bath specialty shop.

Q. I have a third floor walk-up attic that had been finished (floor, ceiling, windows, electric), but not insulated. The plan is to have a more usable play/study/storage area. Electric heat will be used to condition the space. Sloped ceilings on both sides. A knee wall will be along one side for storage while the other side will be as is. Collar ties exist at the ridge. The peak ceiling is about 6 feet in the middle of the room.

Currently there is a soffit and ridge vent, but they will be covered by the foam. The windows on the gable ends are opened and closed as needed.

Most of the drywall pieces need to be cut down as the windows are too small for boom delivery of the drywall and can be installed without problem, but the full height wall/ceiling is where the question comes from. That is where we'd like to have something other than drywall with a seam in the expanse.

A. When you say that the ceiling is finished, it does not jibe with the rest of your description so I'll assume that the collar ties are visible and that there is no ceiling finish.

Why would you make the ridge and soffit venting no longer functioning by insulating with what I assume you mean sprayed foam?

I would suggest that you install ready-made full width baffles along the entire length of the rafters or, for additional insulation, tack 1-by-2-inch wood strips to each side of the rafters tight to the roof sheathing.

Tack 1-inch thick or thicker XPS rigid insulation to the rafters under the wood strips. This will keep the ventilation system working as it should for moisture and temperature control and the health of the roof covering.

Complete the full rafter insulation with Roxul mineral wool from the wall plates to the collar ties. Do this even on the side with the knee wall so the storage will be inside conditioned space.

Insulate the collar ties with R-32 Roxul. Unfortunately, the low ceiling height does not permit the application of rigid XPS to the bottom of the collar ties.

To avoid having to cut the drywall to be able to get it into the attic, you can choose any type of wood paneling. You will not need to staple a plastic vapor retarder since the XPS and the Roxul in the rafter spaces will control most of the moisture migration, as will the Roxul on the ceiling.

Q. I had a driveway reinstalled on Dec. 4, 2016 (timing was probably poor).

The contractor promised two inches of blacktop over a stone base (he later mentioned that he used crushed concrete for the base). Water runs across the driveway in a few places, it does not sit for more than one day. In each of the places where the water runs over there is a white chalky looking sediment on the driveway, this started the first day after installation. My guess is it is lime from the crushed concrete coming to the surface. The blacktop appears to be a little coarse to me.

Do you think there is a solution to the problem? I was considering having the driveway sealed in hopes that it would color the stains and protect it.

I have phoned the contractor but he still has not looked at the problem and I am not sure he is going to be able to help.

A. A properly constructed asphalt driveway should consist of 6 to 8 inches of crushed stones, a 2-inch layer of bottom course and a 1.5-inch layer of surface course and it should be properly compacted. It should not be done in cold weather.

It does not seem that it is what you got.

The white, chalky residue is normal; it is caused by mineral salts or calcium carbonate leaching from the soil as a result of water runoff. It could also be from the lime in the crushed concrete. Time will take care of them.

Seal-coating should not be done on new asphalt until it has turned a light gray, indicating that the oils have evaporated. This may take two or more years depending on the driveway's exposure to the sun.

Seal-coating is best done in a thin application, and should not be done again until signs of wear are apparent.

At this point, it is probably best to have an experienced seal coating contractor look your driveway over and tell you if he or she would recommend the application of a finer layer of asphalt or if seal coating will be sufficient to seal the present asphalt.

You may also want to consult with another asphalt contractor for his/her take on the present condition.

When ready to apply a seal coating, try to get a coal tar sealer, which is still available in some locations even though it has been banned in a number of cities and some states as an environmentally unsafe product.

You will have to find a seal coating contractor who still uses it. It is the most durable sealer for asphalt, lasting some five years - longer than the more environmentally safe sealers that have only a two- to three-year life expectancy. It is the sealer used on most airport runways as it offers the best protection against jet fuel emissions.

As an alternative, you may want to look at asphalt emulsion sealers, but be aware that they do not stand up as well as coal tar pitch-based sealers to the UV rays of the sun and petroleum-based spills, such as gasoline and oil leaks from automobiles, etc.

• Henri de Marne, a former remodeling contractor turned columnist and consultant, is the author of "About the House with Henri de Marne" (Upper Access Publishing). He continues to take questions from readers for this column and his website, www.henridemarne.com. Email questions to aboutthehouse@gmavt.net.