Moldy Crawlspace in an old house. What's the best way to paint this area? Get rid of musty odor?

Greetings.


I have a house built about 1890.  It's not a gracious old mansion or anything particularly special. It was built on brick piers with 6X6 oak beams running between the piers.  It has no basement and the clearance between the ground underneath and the oak beams is between 12 and 30 inches. 

My question for you is if there's an Earthpaint product or products that you'd recommend to seal the beams against further moisture damage.  If so, I'd appreciate any thoughts on what to use and what kind of preparation I'd need to to do.  I'm thinking that I might also apply Lime Prime to the beams for protection against mold.  And I'm unsure of whether I'd need to clean the wood before applying Lime Prime.

I plan to put 6 mil plastic in the crawl space for a vapor barrier as part of insulating the crawl space.  Of course there is no vapor barrier between the brick piers and the oak beams.  And as a result over the years, there has been some damage to the beams from moisture being wicked up through the brick and mortar support piers. Ideally, I'd like to raise the support beams enough to insert a moisture barrier.  But I'm still researching the feasibility of that. 



Thanks for any advice and assistance you can offer.

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Hi xxxxx, 

If the crawlspace / basement area is very moldy, musty, dirty, then we get extension poles, cover up safely, and blow it all out with a 3500 psi pressure washer and 15* nozzle.

Try not to introduce too much water, let the air do most of the work and the heavy water particles cling and carry debris out an exit or to the floor. (A compressor can theoretically be used without introducing water but this is very, very dirty and impractical). If the space was bigger you could use a broom...

Dry with a few fans and fresh air <14% m.c. 
Replace any rot or make structural repairs. 

For low to ground crawlspaces we usually spray Lime Prime on everything; ground, beams, walls, everything. Just to clean it all up.
Then we take it a look at it all and see what we are dealing with. On old homes, the crawlspace can have a big effect on the overall smell of the house. This is another reason we might consider coating the entire crawlspace well with Lime Prime. 

We don't always apply a sealer over Lime Prime in basements, crawlspaces. That depends on the space. Lime Prime is engineered to permit vapor transmission (breathable) and not trap moisture. Often, we want the wood to breath but if it's wicking moisture then sometimes it is best to put a sealer to reduce the woods' ability to wick moisture. 

If that is the case, then we try to dry the wood <12-14% moisture content then we spray the wood and masonry with Lime Seal x 2 coats to create a waterproof seal over Lime Prime. Never seal wet wood. It will rot. It it's wet (>16-18% m.c.) coat with Lime Prime, let dry and come back to touch up after it's dry. This way it dries out safely.

That's a good solid finish for an area that has constant moisture exposure and high mold susceptibility.

A couple affordable tricks of the trade that might come in handy. If the crawlspace floor is dirt it tends to attract mold, moisture, critters and odors. 

Bentonite Clay - cheap and effective to spread on dirt floors to help keep them clean of odors and reduce moisture damage.

Pond Liners -  holds up better than regular plastic.

So, a moldy, close to the ground crawlspace finish schedule would look something like:
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1. Clean as desired to allow Lime Prime to adhere and penetrate. 
2. Lime Prime everything. ( 2 coats on severe areas)
3. Lime Seal x 2 coats (if wood is wicking moisture)
4. Spread Bentonite on the dirt
5. Lay a pond liner over the bentonite. 
6. Make sure air can circulate after doors are closed. 

Hope this helps.
Best wishes,
Tom

Sample pints are recommended for creating a finished sample in advance.