Damp house? Check your heating system

Q: In your response to the homeowner who was experiencing sticky wood surfaces and sagging floors, you stated that high humidity could be the reason, and that several factors could cause the humidity, such as blocked attic vents. Your piece did mention heating equipment (such as heat/hot water boilers) as a possible source, but not effectively.

The humidity situation could also be caused by infiltration of exhaust gases from heating equipment into the living areas. This can cause deadly dangerous conditions, particularly to sleeping persons.

A friend of mine had a similar moisture situation 20 years ago in a house he purchased. The professionals he hired couldn’t find the cause. Eventually, he located it himself: Critters nesting in his chimney had blocked the exiting gases, causing them to back up into his home. Additionally, in cold climates, snow can block exhaust vents; building specifications in the Northeast were only recently changed to prevent this kind of occurrence.

Another danger I believe needs attention is crumbling chimney stacks. In the Northeast, many “oil burners” have been converted to gas. These gas heaters are routinely hooked up to the pre-existing brick chimneys. Gas exhaust is cleaner, but more chemically corrosive and “wetter” than oil exhaust. It also condenses earlier than oil exhaust, leaving chemical deposits on the upper half of the chimney that break down the mortar and bricks much faster.

“Critters” and debris-blocked chimneys are just two among a litany of “quiet” problems that can develop in any home. I hope these are worth considering. — Rich L., Quincy, Mass.

A: They are definitely worth considering! Rich, thank you for bringing this potentially life-saving information to readers.

HOME TIP: Summer is a good time to schedule a chimney inspection and cleaning — a maintenance item that should be done annually.