Answers to Attic Questions #1

The corner of an old, dimly-lit attic with a couple windows on the near wall.

Part of being a DIY-er is knowing when to seek expert advice. The following questions cover everything about attics, from ventilation to access doors, and each one received an expert answer. Find out if your answer is on the list.

Q. I have two turbines on my roof and only one rotates. The builder said it doesn't matter since the soffit is ventilated all the way around the house. He said most builders do not do this, which is true because I went around town and checked for myself. Hot air rises and will escape through the turbine, but I want to be sure it doesn't require a new turbine.

A. That is why code is doing away with them here. When you need them in the summer, there is no wind, so it's just an open hole in the roof. They let rain in. If a storm is coming, you have to take then down and cap the hole. A power vent fan on the t-stats is all you need. They move a lot more air, wind or no wind.

Q. I am trying to insulate the attic of my detached garage. I'm putting up 3 1/2 inch insulation that does not have a vapor barrier and then putting up 4 mil plastic sheeting. The only ventilation is a window at each end, which I open in the summer. I plan to heat it with a small electric heater just when I'm up there in the winter.

I put the insulation up without the plastic and got moisture behind it, so I took it down and let it dry out. I wonder if I need to add some venting or if I'll be all right if I just don't take the insulation all the way to the peak, which is up there about 12 feet or more.

A. Check at home improvement centers. They carry a foam rafter vent that you have to put up first. You can't put insulation up there and let it touch the roof boards. You have to have vents in the overhang. After the insulation is up, you need to have the V/B over it, then drywall.

Q. I am planning to put in an attic floor. There is loose-fill insulation in the attic now. I'm not sure whether it is cellulose or fiberglass, but it looks white like cotton. Do I need to remove the loose-fill insulation, put in the insulation batts, and then install the floor?

A. There's no need to remove old insulation unless it's moisture damaged. If it is still nice and fluffy, I would just leave it there and put your floorboards right over it. If your house is older, it probably is cotton; if it is newer, it probably is fiberglass.

Q. My attic has blown insulation in all but the part that is located above the garage. Is there any added benefit to putting some insulation above the garage? Is there any reason I shouldn't?

A. It's not a heated or cooled area, so it doesn't really need it. The walls between the house and garage should have insulation in them to separate the two areas. Adding insulation above the garage would have very little effect at all, and would probably be a waste of money. A better approach would be to add a layer over the existing insulation in the attic.

Q. Whenever my attic fan is on, a foul smell comes from the shower drain in the master bathroom. On the same floor, a second bathroom does not have this problem. How do I remedy this?

A. If the shower drain trap has dried out, pour a half-liter of water into it. If there's no trap, plug the drain - or tear in and install a trap under your shower.

Q. While on the floor, I'd staple a sheet of Tyvek wrap to the structure, then lift and shim the bottom in place about 1 inch from the concrete walls. I feel this would create a small air barrier, and having the paper on the side facing the concrete would give me something I can rest the R-13 insulation against. Install wallboard, tape, etc. Does this sound right? Does it matter what side of the paper faces the living area?

A. A material should be placed between the insulation and the concrete wall, which is known as a moisture barrier. The sole purpose is to prevent the insulation from touching concrete. Typically, the two best products for this are either tarpaper or 6-mil poly, which is fastened to the concrete. Make sure that this material does not extend above the exterior grade level. Tyvek is an exterior house wrap, which has a completely different function.

Q. Can anyone help with how to install a pull down attic ladder?

A. Are you replacing an existing one or adding a new one? Either way, it will help greatly to have at least two stepladders (6 foot will do) and three adults to perform the installation - one in the attic and two down below. The instructions that come with the unit should provide measurements. I recommend the 6 inch deep steps as being more supportive, since many folks carry a load up or down these things.

Continue on to part 2 for more attic info, or visit our Community Forums for more answers to your home improvement questions.