Crawl space encapsulation?

[s219]

Most people lack the ability to paint.

I had to convince my wife of that over and over. One time she and some sisters painted a room and it was so bad I had to leave before I said something mean. I looked at that for years and had heartburn. I can do an OK job painting if I focus on it, plus my brother was a painter for many years and taught me a few tricks. But it's hard work for me to make it look perfect so I don't enjoy it. When we built our new home the painters were awesome and made it look easy. They also had lots of good tools, many ladders, scaffolding, etc, which typical homeowners lack and can't afford to rent. That finally convinced my wife of the value of a good painter.

The sad thing about the painters is that they were always dealing with someone else's mess, whether it was dust or some other contaminant or issue. And weather was a factor too. I think they were the most under-appreciated sub contractor on the whole project but I made sure to let them know we appreciated their efforts. Some of the best money we spent on the project was on paint work.

 

[s219]

Back to topic, we have an encapsulated crawl and I love it. It's conditioned with the same HVAC as the rest of the house and stays nice and dry. I use it as a warehouse of sorts, storing all kinds of stuff down there. It's about 60% as good as having a basement. One corner of the crawl is 7' tall and we had a slab poured on that end.

The only issue to be aware of is that the liner material puts out a strong plastic smell for at least a year. If you've ever smelled a new pool liner, you'll recognize the odor. If the walls are insulated with foam, that stinks too. You may notice the odors creep into the house depending on if/how the HVAC and venting is setup and under certain weather conditions which change pressure and temperature gradients. It eventually settled down, and I don't notice anything now.

 

[Gomer pyle]

I've been out of pocket for a little while. I had a couple more companies come look at my crawl space. Both companies stated that it was not as bad as I had described to them. I've decided to trench the perimeter, add 3" of pea gravel (a local mulch company can blow it in), tie everything into my French drain, and put down new moisture barrier. I am also planning to install two fans with humistats (not sure of the spelling), the fans come on when the humidity level reaches 50%. When the weather breaks, I'm going to put some fans under the house to try and dry everything out.
I'm really interested in a full encapsulation but can't justify the cost right now.

 

[rScotty]

I've been out of pocket for a little while. I had a couple more companies come look at my crawl space. Both companies stated that it was not as bad as I had described to them. I've decided to trench the perimeter, add 3" of pea gravel (a local mulch company can blow it in), tie everything into my French drain, and put down new moisture barrier. I am also planning to install two fans with humistats (not sure of the spelling), the fans come on when the humidity level reaches 50%. When the weather breaks, I'm going to put some fans under the house to try and dry everything out.
I'm really interested in a full encapsulation but can't justify the cost right now.

There are many different ways to design a trench drain. I'm an engineer and have done several of these. Even the best way is still inexpensive and uses parts from good ol' Home Depot. Dig the trench and line it with a 3 foot wide roll of their porous goetextile cloth, lay the perforated pipe in the bottom of the trench but on top of the cloth, backfill with your three inches of pea gravel, fold the sides of the cloth over the pea gravel, and then backfill with dirt. Be sure to maintain some slope to the pipe so that the pipe can carry the collected water on out to a low spot to let the collected water spill out and drain ..... into a creek or a sump pit is fine. Doing it that way is very little extra expense, and it will move a lot more water away from the foundation.
good luck, rScotty

 

[Gomer pyle]

I haven't been on in a while. Had some surgery and threw my back out working under the house. LOL. I started trenching under the house myself, I just couldn't afford to pay their prices and after reading the post on here I fell confident I can do it myself. I have one side trenched, I just need to remove a few more rocks and roots on the drain end and I'll be ready to lay my pipe. We're having record rain fall here in TN, so I've been checking underneath even when I can't work. The center has no more standing water but the trench looks like a river(thus the rocks and roots I mentioned need to be removed to lower the trench at the positive drain). I feel like I'm on the right track.
I did a lot of research and since my floors have insulation, I either need to remove the insulation and continue using my crawl space vents or I need to encapsulate it and dehumidify. The insulation is holding the humid moisture against the wood which is giving me the high moisture numbers. Checking myself, my joist are at 12% and the crawl space itself fluctuates but right now is at 96%!!! I found crawlspacerepair.com and am going to order everything to encapsulate myself and dehumidify(everything for around $2500).
One question, can I use a Hiliti gun to nail the plastic to the walls? I know it's made to nail into solid concrete but I'm worried about busting the block???

 

[s219]

For my crawl, they shot the foam sheets to the block wall with a Hilti gun.

In the past when I have shot studs/etc into a block wall with a Hilti, I'd always aim for the mortar joints (what I was taught). But I know when the guys shot the foam sheets to the block wall in my foundation, there is no way they were aiming for joints. Couldn't have known where the joints were with a big sheet of foam in the way. I never did see what size/type nails they used. But there didn't seem to be any issues.