Paul Bianchina, Any insulation works for dryer vent pipe
Q: I am running my dryer vent through my unconditioned crawl space and out the adjacent wall. I am using smooth, rigid pipe, and up between the floor joists. What type of insulation do you recommend to wrap the pipe? It’s approximately an 18-foot straight run.
A: You can actually use any type of insulation, the same as if you’re insulating heat ducts. You can use the actual rolled insulation that’s made for wrapping ducts, or just use some unfaced fiberglass. R-11 separated in half lengthwise is fine. Secure the insulation by tying it in place with nylon twine.
Since you said you’re placing the ducts up between the floor joists, if you plan on insulating your floor (always a good idea) then just make sure the dryer duct joints are sealed and then enclose the duct in the floor insulation.
Q: We need help as to how best to remove mold from the painted ceiling of a bathroom. The exhaust fan broke and the mold has accumulated and we want to remove it asap but we do not know what products (hopefully, a non-toxic product) will do the best job of removing the moss.
A: On the painted ceiling of a bathroom that has only been exposed to excess moisture for a short time — for example, just since the fan broke — what you are likely seeing is mildew, not actual mold. Any commercial mildew remover, available at home centers and other retailers, will do the job. Follow the manufacturer’s exact instructions for application, ventilation, safety precautions, and other specifics regarding how to use the product.
However, before starting any work, you first need to evaluate whether or not you’re actually dealing with mold. You can start with an internet search for pictures of both mold and mildew so that you can better evaluate the difference, and then purchase a test kit from one of the home centers that will allow you to test the material.
If mold is present, then removing it is not something I can recommend that you undertake yourself, for liability reasons. The only recommendation I could make would be to contact a mold restoration professional to have the room evaluated and properly remediated.
Also, if you or anyone in your family is experiencing any health problems that seem to coincide with when this first appeared in the bathroom, I strongly recommend that you close off that room and talk with your doctor or other health care professional before proceeding any further.
Once you have all that cleared up, you need to make sure that the exhaust fan has been repaired or replaced, and that it is venting all the way to the outside of the house, NOT just into the attic.
Have a home repair or remodeling question for Paul? He can be reached by email at firstname.lastname@example.org.