Crawl Space Encapsulation

[hausdok]

There is a guy there who claims he can completely seal a crawlspace and install a humidifier in an hour and you pay him $10K? Yeah, right; when pigs fly.

Go here: http://www.crawlspaces.org/

Download their information on sealed crawlspace research. Read it all and then read it again before you commit $10K to any of those guys.

I was in one today. Quiet, dry and warm. Thick white fiberglass mesh reinforced liner about 20 mils thick.

It was raining cats and dogs all day here today and the wind was howling. It dang near knocked me off the roof at one point. Inside that crawl, it was a snug 57 degrees and quiet and dry as a bone, Every ten minutes or so the silence was interrupted by the sound of the pump coming on for about ten seconds.

Very professional job. They'd removed all the pre-existing insulation from beneath the floors, closed and sealed all vents and the mud sill and rim at the perimeter. Removed the old vapor barrier and all debris, leveled the floor, added a layer of pea gravel, installed a deep sump and then installed a really heavy vapor barrier over the floor, pier pads and up the walls to about an inch from the top of the foundation wall.

A very professional sump pump installation sunk into the low spot in one corner pumped out to a bell receptor next to the foundation. The pipe that receptor is connected to runs underground to the property line and then empties into a long stone drywell at the back of the property.

The sump pump was completely sealed and the vapor barrier was integrated into the seal. There were several one-way drains in the barrier to allow water to drain through the barrier in the event they have a plumbing leak or a washing machine overflow.

There is an 8-inch long probe that extends into the top of the sump well. If water rises to the end of that probe because the pump isn't working it will sound an alarm. Several more of those probes were sunk through the barrier at the other corners and are integrated into the alarm system.

There is a large industrial grade dehumidifier that comes on automatically if the humidity goes beyond the threshold they have it set for. That dehumidifier drains via a pipe to the sump well. Every probe, every wire, every pipe that passes through that barrier is carefully sealed.

It was truly a thing of beauty.

I always do the crawlspace last because I dread the filth and the crawling and scooting and knee walking and general discomfort and effort that it requires. Usually when I come out of those I feel like I've had the snot kicked out of me by the Seahawks. Not so today. Came out clean dry and actually not smelling foul for a change.

I can't wait till this becomes SOP around here and stink hole crawls are a thing of the past.

ONE TEAM - ONE FIGHT!!!

Mike

[tim5055]

Thanks Mike, that is what all the companies say I will end up with!

[palmettoinspect]

I too hope this becomes SOP. Clean crawlspaces get me excited!

[Marc]

I don't see what an SOP has to do with. Municipalities could address moisture issues in crawls if the public would tolerate it.

Marc

[Tom Raymond]

You need to take a break buddy. Kiel was waxing on about how nice it would be if all crawls were sealed and conditioned.

[hausdok]

You're thinking about the wrong type of SOP, Marc

I'm referring to Standard Operational Procedure - not Standard of Practice.

ONE TEAM - ONE FIGHT!!!

Mike

[tim5055]

Well, a company has been selected and as soon as the septic folks finish their job connectiong us to the sewer system the crawl will be dry, with pretty white plastic everywhere.

I will follow up with pictures when they are done.

Thanks for everyone's help and support!

[Marc]

Maybe include some 'before' photos.

Marc

[tim5055]

OK Marc, here are a few before shots, but please note the great job the contractor did with the original vapor barrier.

[Erby]

Pictures way too LARGE! Maybe reduce them for easier viewing?

[tim5055]

Pictures way too LARGE! Maybe reduce them for easier viewing?

I cut them down 50%

More?

Thanks for looking.

[John Bubber]

Encapsulation is not the solution for all wet, leaking crawlspaces.

St Clair Shores MI, crawlspace-wall bowing in, multiple exterior gaps, cracks which was why and where the water entered and puddled on floor.

http://picasaweb.google.com/10104903458 ... 9188493442

Same house, some deteriorated-disintegrated exterior blocks

http://picasaweb.google.com/10104903458 ... 3328086770

The rest of this photo album, click each to enlarge if you like

http://picasaweb.google.com/10104903458 ... Crawlspace

For those homeowners who have THESE types of problems, they obviously need exterior waterproofing as NO encapsulation would stop-prevent further water from entering and would not stop-prevent further deterioration of blocks, wall.

Another point is, seems most if not all of the interior basement drainage system companies only 'n lone supposed solution for every leaky basement or crawl is, an interior water diverting system.

These self proclaimed experts rarely if ever take the time to correctly and honestly diagnose, determine how/where the water is actually entering. They don't seem to care or understand what occurs on the outside. That is incompetence, negligence.

[tim5055]

Encapsulation work has started.

Step 1, close and seal all vents. Each vent closed and a 3" think foam board is cut to fit - then foamed into place.

Step 2, Rim joist foamed and sealed around the entire house.

Step 3, the plastic is put up on all walls.

Several inches of the top of the foundation is left uncovered for termite inspection. The entire job should take 2 - 3 days. I will keep posting photos as they work.

[tim5055]

Well, here are the before & after shots. I tried to take the afters as close to where the before shots were made.

I'm happy with the outcome and only time will tell if it was a worthwhile expenditure. Watching for the past three days tells me that the company made a good profit. But, would I be willing to do it myself - no. The job took 2 1/2 days. Two guys were there the full time and two other guys were in and out. My best guess is 60 man-hours work. They worked from the time they arrived until they left, no slacking.

[kurt]

It looks like a reasonably competent job in a complicated environment. Retrofitting that crap around a lot of columns and existing mechanical (even if it's something as simple as a couple drains) takes a surprising amount of time; it's an ass kicker.

You will notice a difference. I would be surprised if you didn't.

[tim5055]

You will notice a difference. I would be surprised if you didn't.

Well, I've been watching the dehumidifier and it's pumping out quite a bit of water.

[kurt]

Of course it is. It may continue to do so. But at least you have taken the steps where a dehumidifier can start to incrementally bring RH down and keep it down. Before, running the dehumidifier was silly; there's no way you could appreciably effect RH without a vapor retarder. You will notice variation between seasons, or at least I would expect you to see some differences. How much, I have no idea. Gotta measure to know.

Understand, that little amount of concrete that allows a termite inspection will wick some amount of moisture into the place; no way around it. But, it's not likely to significantly effect RH.

[tim5055]

Of course it is. It may continue to do so. But at least you have taken the steps where a dehumidifier can start to incrementally bring RH down and keep it down. Before, running the dehumidifier was silly; there's no way you could appreciably effect RH without a vapor retarder. You will notice variation between seasons, or at least I would expect you to see some differences. How much, I have no idea. Gotta measure to know.

Understand, that little amount of concrete that allows a termite inspection will wick some amount of moisture into the place; no way around it. But, it's not likely to significantly effect RH.

I'm already looking for a RF thermometer/humidistat so I can watch the temperature difference between the crawl and the house. I'm told that with "leakage" in the ductwork they will eventually get "close". I'd like to know what close is

[Marc]

Regardless of the exact measure of benefit, you should realize a significant ROI when you next move. That's a very clean crawl. It tends to invite you in.

Marc

[tim5055]

I'm already looking for a RF thermometer/humidistat so I can watch the temperature difference between the crawl and the house. I'm told that with "leakage" in the ductwork they will eventually get "close". I'd like to know what close is

OK, I have the thermometer/humidistat running in the crawl. It may take a day or two to settle, but what RH should I be shooting for in the crawl? Once it gets there I can dial back the dehumidifier as the dial on it just says dryer with an arrow to the right.

[hausdok]

If it's a new tight house, maybe 55% or less. If it's an older, draftier house, look for less than 50%.

[kurt]

That'd be about what I'd guess. At this point, it doesn't matter. You've made as much improvement as anyone ever makes. The RH is going to be whatever it is.

Find out and tell us; it's useful nerd data.

[tim5055]

That'd be about what I'd guess. At this point, it doesn't matter. You've made as much improvement as anyone ever makes. The RH is going to be whatever it is.

Find out and tell us; it's useful nerd data.

I guess you can consider me one of the nerds. I purchased THIS weather station as well as an additional temperature/humidity sensor for the crawl. It gives me the information I wanted and allows me to stream it tot he web where I can look at it on my smartphone.

As of right now this is what I show (purple is outside/green is crawl)

[hausdok]

I think you might want to dial back the humidifier. At 40% you might end up with interior humidity traveling to the crawl. I think you want to be somewhere near 50/50 with just a tad toward the dry side in an older crawl.

Personal opinion based on not a whit of science. Just seems to work for me in my locale. If I were practicing in S.C. or Texas or California, I'd probably revise my opinion after I'd been living there long enough to figure out what I think is working.

ONE TEAM - ONE FIGHT!!!

Mike

[tim5055]

I think you might want to dial back the humidifier. At 40% you might end up with interior humidity traveling to the crawl. I think you want to be somewhere near 50/50 with just a tad toward the dry side in an older crawl.

Personal opinion based on not a whit of science. Just seems to work for me in my locale. If I were practicing in S.C. or Texas or California, I'd probably revise my opinion after I'd been living there long enough to figure out what I think is working.

ONE TEAM - ONE FIGHT!!!

Mike

Thanks!! Right now the sensor is just sitting on a shelf by the door to the crawl. Prior to encapsulation there was no mold in this area, so I assume my crawl has several micro-climates. I'm moving the sensor to the area that had black mold under the insulation and on the joists and see how the readings change.