Crawlspace Help

[MRM]

I was planning on doing complete sealed and adding a dehumidifier. Try to do exactly what they were going to do for 1/4 the price.

This is it. The dehumidifier you want is 800+
There is a concentrate they sell at hd you mix with bleach and water. Hose all the wood down for the mold.
I'm closing on a house next month and I'll be doing the same thing.
I got some of the encapsulation tarps cheap from a deal on here. It's been a while, but, maybe there are some left.

If you are on a septic tank, I'd either put a filter on the washer discharge or run it out to the yard (unlawful.).

 

[ADAduckhuntr]

Keep in mind it needs to breathe even with the plastic barrier down. Leave about 12” all the way around the edge open so it can exhaust to the vents.

The vented crawlspace is the problem!
If your floor (the barrier to the conditioned space) isn't perfectly sealed (air and vapor), you'll eventually be in trouble.
Read the building science links.

Signed,
Your friendly neighborhood LEED AP

 

[MRM]

I found an old pm. I sent him a message to see if he had any of those tarps left.

 

[ADAduckhuntr]

https://www.buildingscience.com/documents/insights/bsi-015-top-ten-dumb-things-to-do-in-the-south

See #10

 

[Just1more]

https://www.buildingscience.com/documents/insights/bsi-015-top-ten-dumb-things-to-do-in-the-south

See #10

Makes since. They do things different these days than years ago. My current house has a fully encapsulated attic. Hottest day of summer it was 84 degrees up there.

 

[Wolf six]

what about adding vapor barrier to the floor joists

 

[coolformula]

I have a TON of documents if you want to PM me on this subject. Case studies and info.

Get a RH meter. Aslo Get the meter to stick into the wood for the RH of the wood as well.

Get a remote RH and temp meter to constantly monitor before and after the remediation work.

Full encapsulation here runs 7 to 15k. If you can find people you and do it much cheaper, buying your own things. I would go with at least a 8MIL VP.

Don't buy the 150 dehumidifier it won't work or work for long. You want a santa fe or something in the upper PRO line like that.

This is a huge business. The buildings codes in some states have changed, but not in TN/GA/AL

I doubt homeowners will pay for these repairs, but it could depending on your policy.

You may need a sump pump as well if you have major issues.

Put all gutters underground 10 feet from the house with pop up valves.

Fix any grading issues if you can.

What got me into this was one day a, at a family event, we get off the couch, we hear a LOUD crack. Go under the house and quite a few floor joists were broken in half like tooth picks. House was 40+ years old and very crappy vapor barrier. Water/humidity had rotted the wood.

It blows my mind in 2020 we have not updated the building codes. If you talk to builders who been doing this for a long, most will tell you you need a vented crawlspace, run away from these people.

 

[Willhangfire]

There is a lot of darn good info in this thread! I've been dealing with crawlspace moisture issues for 33 years. I've read articles by supposed experts that say to open vents in warmer months and close them in Winter. Some say keep them closed all the time so its hard to know what is good advice. Encapsulating it is an expensive proposition and would pay for hundreds of months of electric bills running a dehumidifier. I'm thinking I'll install a Crawlspace fan with a built in humidistat to start with and see if that does the trick.

 

[Brennyss]

With what material it's better to cover the walls in the crawlspace, can someone tell me?

 

[ADAduckhuntr]

With what material it's better to cover the walls in the crawlspace, can someone tell me?

Rigid (XPS) insulation board.
Read the building science links.