Q&A on how to dry out & fix up a wet crawl space, set#2.

The article series gives three key steps to get water and moisture out of a building crawl area following water entry, storm flooding, or a sewer backup. Here we summarize a safe and effective approach to removing water from a wet or flooded crawl space.

Q&A: How to Dry Out a Crawl Space Quickly

These questions & answers on the Step by Step Guide to Drying out the Crawl Area were posted originally at CRAWL SPACE DRY-OUT PROCEDURE so be sure to review that article too.

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On 2018-12-30 by (mod) - A rat chewed through a water pipe in my crawl space - dry out?

Adam

My very best crawl space dry-out advice is given in the article CRAWL SPACE DRY-OUT PROCEDURE, better organized and more complete than if I try to write it again off-the cuff.

Remove the wet materials, pump out standing water, use fans, dehumidifiers, heat to dry the space.

Inspect for and remove mold contamination or other contaminants if appropriate (such as sewage)

Please please take a look, then let me know what was unclear or what questions remain.

On 2018-12-30 by Adam - how do i dry it out?

A rat chewed through a water pipe in my crawl space and when i found the leak there was 2-4 inches of water on the ground and the insulation was saturated. i fixed the leak and plan on removing the wet insulation and vapor barrier and replacing them once things are dry. my question is though,

how do i dry it out? putting a fan under the house seems like a good idea but I am unsure what else to do.

On 2018-08-26 by Klein - flood seeped into the crawl

Our crawl space has been encapsulated with a few layers of plastic professionally.

We recently had a flood in our laundry room and it seeped into the crawl. The water has gone through the seams of the layers and we don’t know how to dry it out. We are concerned about mold growing between the layers of plastic. Any suggestions?

On 2017-09-05 by (mod) - why venting increases crawl area moisture

Because warm moist summer air (depending on where you live) entering the cooler crawl space actually adds moisture through those little vent openings without ever ventilating enough to dry out the area,
current best practice is to seal the crawl space,

ix any sources of water entry

put down 6 mil poly

and perhaps run a dehumidifier

or dehumidifier + fan to dry out the area

On 2017-09-05 by Ken

We have a four foot dirt crawl space under our home....and three small vents that we open in the summer months to allow outside air into our crawl space under our home.

However, our crawl space is still damp. Is this a good idea...or should we seal these three vent holes up ?

On 2017-06-09 by (mod) - If you're going to put down concrete in the craw

Skip

If you're going to put down concrete in the crawl, it might make sense to

dry out the area, exhausting air to the outdoors

then
have a cleanup company apply a sanitizing spray to the surfaces
then

cover the ground with 6 mil poly before you add the concrete.

That will perhaps slow the concrete cure and temporarily drive more moisture into the crawl area but the slab cure is not, in proper concrete installation, dependent on getting rid of water by having it soak into the soil.

On 2017-06-09 by skip

My crawl space is unfinished and has gravel, I was affected with level 3 sewage water (backed up from the city due to flooding in the area).

I have already emptied it and de-contaminated the whole area and wanted to know should I remove the gravel and put cement or just put cement on top of existing gravel without removing the gravel.

I want to avoid future problems down the road. Please let me know what is the best thing to do?

Thanks in advance Skip

On 2016-09-04 by Anonymous

Thank you for your advice!

On 2016-09-03 by (mod) - freezing door locks in Minnesota: tried spraying lock antifreeze in the door knob but that didn't work.

I'd look more carefully at the lubricant being used in your lock.

When using a lock de-icer, as it's also a solvent, it's important to re-lubricate the lock afterwards; for years I used a dry spray graphite powder; some folks soak the lock in WD40 - that's been reliable for me too. Be sure to wipe off any excess lubricant that runs out of the lock as some can damage door or other surfaces, particularly painted surfaces.

A lot of articles on freezing building door locks suggest covering the lock with something: a plastic baggie, a tennis ball, an outdoor hose bibb protector, or other kludgy solutions.

I don't like these as it ought to be possible to prevent a lock from freezing or to choose a lock model and lubricant that avoid the trouble.

Figure this, thousands of those locks have been sold and installed on homes, most likely including in your area. If others are not having the lock freeze up problem, let's ask "What's different at this home?" - lubrication issue? unusual interior moisture levels? wind-blown rain and snow in this location?

(If so then locks facing the winter ought to be giving more trouble); lock model? Some door locks include a metal shield to help keep moisture from entering the lock through the keyhole; temperature? Does the storm door leak?

re freezing winds blowing into the entry door space between storm and main door? What sort of door is installed? Metal, uninsulated, or solid wood or insulated?

A storm door ought to eliminate wind-blown rain / snow as an issue, but not if it's drafty.

Perhaps part of the trouble is your specific lock brand and model. If you decide to try different lock brands or models, check with the manufacturer about their product and ask about the lowest-temperature at which the lock is expected to operate properly/

In a freezing Minnesota climate some people including at a home in our family are using Kwikset (912?) battery-operated door locks or with the Yale Zigbe Control-4 door lock; even if the tumbler were frozen the indoor batteries and lock mechanism will open the door when the proper combination is pressed.

On 2016-09-03 by Maria

Last winter I tried spraying lock antifreeze in the door knob but that didn't work. I carried a blow drier around so that I could get into the house. I even took the door knob apart every couple days so that I could bake them in the oven to dry them out.

After I took them out of the oven I would spray a lock lubricant into them so they wouldn't dry out too much. I installed new knows and in a matter of days the same problem happened. I have a storm door infront of the main door with the kno s freezing up. Any other solutions?

On 2016-09-02 by (mod) - locks do freeze - STP lock antifreeze.

I don't know, of course, who's included in the "no one" but certainly I've heard of locks freezing up; even wind-blown snow or rain can get into and freeze a lock.

Stop by your auto supply store and pick up some STP lock antifreeze. Try a shot of that in your door locks. Be sure to wipe off any runout of the antifreeze.

On 2016-09-02 by Maria

I live in northern Alberta, Canada. I bought this house about 1.5 yrs ago and last winter I had problems with my door locks freezing up. It was to the point where I could put my key in the lock. I don't have a lot of moisture in the house.

This year I put in exhaust fans in the bathroom and above the stove. I also have a dehumidifier running all the time. My crawl space is mostly a dirt floor with a small area of concert where the furnace sits on. It has been raining a lot the past month and I noticed that along 2 of the walls there is some damp soil downstairs.

I have a fan running down there all the time to dry it up. What can I do now that will prevent the door locks from freezing up again this winter?

Along the one wall with the damp soil has a large outside deck along it and the otherside has a driveway.I have had about 4 or 5 different trades in here looking at what might be the problem and no one can come up with an answer.

No one seems to of heard the of this problem before.

On 2014-12-01 by (mod) -

Ok

On 2014-12-01 by SEGeorgia

Thank you for the information! After rereading my post I realized I omitted the information indicating the fiberglass batting is actually up under the floor, not on the ground with the vapor barrier-apologies for the confusion.

It is falling down in some places, probably from the moisture, so new insulation and placement will be important too. The pest company did not give us copies of their photos but I will send you ours as soon as I get a respirator and check it out for myself.

On 2014-11-27 by (mod) -

Really? Fiberglass placed on the ground? That's not a great idea - it invites moisture and mold contamination in the fiberglass and loss of insulation value. Most builders place fiberglass up under the floor. In sum: we want

- new clean dry insulation under the floor not on the ground

- a solid poly vapor barrier over the dirt surface

- steps outside to keep water away from the foundation - roof gutter repairs, downspout extensions, sloping grade away

If the area is truly moldy it may need to be cleaned and sealed (the floor framing system) before insulating there.

None of the work is technically difficult and almost anything you do will be better than what you describe. If you like use our CONTACT US link to send me some photos and I'll comment further.

On 2014-11-27 by SEGeorgia

We bought a 2007, 2-story home with a sloped, open crawl space 6 months ago in Southeast Georgia. It has an earth floor and cinder block walls with a height varying from 2.5 feet to 8”. It has yellow fiberglass batting and a loose vapor barrier on the ground. I think the square footage is about 1500 SF.

The home inspector told us there was some moisture in the crawl space and to add gutters as well as buried pipes to direct the water away from the house. We did this immediately.

After extensive rainfall this month, we had a national pest control company inspect the crawlspace. They showed us numerous photos of moisture problems, possible mold or “mold like” substance on the floor joists and fungus on the sill under our master bedroom.

They also said the wood and wall in that area were so wet they were sweating.

They wrote down their options on a piece of paper. The cheapest one was to remove/replace insulation and vapor barrier, treat/protect wood and install sub floor insulation for just over $10,000.

To encapsulation with dehumidifier would be around $16,000 (electrician not included). They did not have a printout or a sheet of any kind for these services and wouldn’t tell us the cost break down of materials or labor.

Are these price points or method of quoting typical?

I would like to do some of this myself given these prices. If anyone could provide suggestions on what I can do on my own and what I should leave up to the professionals,

I would greatly appreciate it. I have very little knowledge of carpentry work but not afraid of grunt work. Thanks!!

...

Continue reading at CRAWL SPACE MOISTURE BARRIERS or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see these

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• CRAWL SPACE DRYOUT - home
  • CRAWL SPACE DEHUMIDIFICATION
  • CRAWL SPACE DRY-OUT PROCEDURE
  • CRAWL SPACE GROUND COVERS
  • CRAWL SPACE MOISTURE BARRIERS
  • CRAWL SPACE SEAL & SANITIZE
  • CRAWL SPACE WATER ENTRY STOP
  • CRAWL SPACE WATERPROOFING

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