What is a good basement dehumifidier that I can install in a 750 square foot basement?
GBA Editor
| Posted in General Questions on
Besides the basement being musty my upstairs rooms in my 4 story brownstone also have that musty smell. I believe the basement air is being drawn up (stack effect) in the both the old non-working fireplaces ( 2 per floor) and in the annular space between the exterior brick and plaster walls. Should I also blow in insulation in this annular space and seal the fireplaces?
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Search and download construction details
Replies
First, find the source of the moisture and eliminate that if possible. Exterior grading? Roof runoff with inadequate or absent gutters and downspouts? Leaky foundation walls? Uncovered earthen basement floor?
Once you've reduced or eliminated the sources, then tighten up the entire structure from the top down and seal the unused fireplaces to control stack effect air movement. You might find that you don't need to run an energy-consuming dehumidifier at that point.
Basement floor is concrete and the walls have a concrete skim coat over the old stone foundation. Both are in good shape. House is attached on one side. The other long side has a brick face ( roughly 40' x 40') that meets a concrete sidewalk - there's a slight gap here (mostly less than 1/2 inch - but I've added concrete here at a 45 degree angle to let the water drain to the sidewalk, then a driveway and their drains. I don't think that's the cause of the water problem - but I certainly could be mistaken. Flat roof drains directly to sewer via exterior downspout - no water leaking here. Basement just has that damp feeling without an obvious source of water.