Heritage Restoration, Inc.

Musty basement

We have a walkout basement.  The basement is more than musty smelling.  We do use air conditioning, but I think we need more help.  Can you help?

Arleen

There are several ways to reduce the musty smell in a basement, although it depends on your house’s conditions and the level of intervention you wish to do.  Here are some things to consider:

Runoff, Gutters and Downspouts
The best way to reduce moisture quickly, cheaply, and without using electrical appliances is good water management.  The house’s grounds should be sloped away from the foundation.  Be sure all of the downspout bottoms are clear and dispensing water after the ground starts to slope away.  There are downspout extensions that help move the water away.  Sometimes it takes a bit of experimentation.

Make sure your gutters are clear of debris and water goes down the downspouts, not over the edge.  We had some good rains that have overwhelmed gutters, which is OK, but gutters should not be clogged to prevent proper water management during a normal rainfall.

Foundation Leaks
We are fortunate in New England to have a long architectural history with many foundation types.  But stone foundations have many joints that can leak.  Sometimes there is a quick fix, other times foundation re-pointing is necessary.  Sometimes leaks can be fixed from the inside, where a good mason or basement waterproofing company can take care of it.  But beware, sealing an interior of a basement can fail quickly since hydrostatic pressure, or water pushing from the outside, can cause interior repairs to fail or cause masonry more damage.

Another thing to look at is hardscape surfaces touching your foundation.  Walkways, driveways, patios and other non-porous surfaces have cracks against the foundation making an easy route to your basement.  Managing water through gutters helps, but sometimes the hardscapes must be re-pitched for proper runoff.  Trying to caulk or seal in between them are only short-term fixes.

Relative humidity and Moisture
Relative humidity is the ratio of the current absolute humidity to the highest possible absolute humidity, which depends on the current air temperature.  People tend to feel most comfortable at about 45 percent relative humidity.  If your air conditioning is one zone, the basement may need more dehumidification than the rest of the house.  So while a dehumidifier will warm the basement a bit, it will reduce the relative humidity enough to help balance the relative humidity.  Either that, or create a separate air conditioning zone with dehumidification.

You may also have many moisture absorbing materials, like couches, rugs, drywall, etc.  Sometimes the basement can be designed to allow moisture to escape better, like air spaces and moisture barriers.  You may want to consider replacing items that have excessive musty smells.

So I hope this helps.  Take a stepped approach from the easiest quick fixes to the mechanical.  It can save you time, money and energy.

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