Crawlspace encapsulation

[mellow]

For you guys that have had the encapsulation done, was it worth it? What to you made it worth it?

I have 2 quotes I am going on, one being a basic new vapor barrier and blah blah blah, and the other is the full encapsulation with a dehumidifier for double the amount.

Just looking for some real world experience if it is really worth more to fully encapsulate or is it just marketing?

Would a basic vapor barrier setup do just as good? My house was built in the late 1970's and is a rancher layout, the current plastic is about gone so it needs a new vapor barrier put down, just can't figure out if full encapsulation is marketing hype or really has benefits?

 

[mellow]

Here are my options:

1.

REMOVE DEBRIS FROM CRAWL SPACE ALONG WITH OLD VAPOR BARRIER
TREAT ALL EXPOSED WOOD WITH BORATE FOR MOLD, MILDEW AND FUNGUS
ADD UNFACED INSULATION TO EXISTING INSULATION TO INCREASE R VALUE
INSTALL NEW VAPOR BARRIER

2.

REMOVE DEBRIS FROM CRAWL SPACE ALONG WITH OLD VAPOR BARRIER
TREAT ALL EXPOSED WOOD WITH BORATE FOR MOLD, MILDEW AND FUNGUS
ADD UNFACED INSULATION TO EXISTING INSULATION TO INCREASE R VALUE
INSTALL REINFORCED NYLON MESH MEMBRANE TO ENCAPSULATE CRAWL SPACE
INSTALL DEHUMIDIFIER WITH CONDENSATE PUMP
SEAL ALL SEAMS WITH WHITE VINYL TAPE

 

[BigJ273]

I’ve been round and round with this idea for years. I finally ripped out the vapor barrier myself and put a new one down. Bought the seam tape and did it all myself. It was a lot of work, but it cost me about $300 for the supplies. They wanted $3k to just replace the barrier.
As for encapsulation, I’ve seen PLENTY of encapsulated crawl spaces with two inches of water in them. Hot, humid air is ur biggest enemy in the summer. It mixes w the cool air from the floors and creates moisture in the crawl space.
I’m also very skeptical of completely sealing up a space that has, for the past 100 years, been told to keep aired out.
Encapsulation companies are salesmen, they have a product they are trying to sell. The reality is your crawl space probably looks like every other one on ur block. And if there’s not major damage or signs of damage since the 70’s, I’d say ur prob fine. Now, if ur having major mold growth or water intrusion, that’s a completely different story……

 

[EbS-P]

For you guys that have had the encapsulation done, was it worth it? What to you made it worth it?

I have 2 quotes I am going on, one being a basic new vapor barrier and blah blah blah, and the other is the full encapsulation with a dehumidifier for double the amount.

Just looking for some real world experience if it is really worth more to fully encapsulate or is it just marketing?

Would a basic vapor barrier setup do just as good? My house was built in the late 1970's and is a rancher layout, the current plastic is about gone so it needs a new vapor barrier put down, just can't figure out if full encapsulation is marketing hype or really has benefits?

I have been kicking around the same ideas. I started tracking the humidity in my crawl space. It’s high enough that I feel like I should do something. But it won’t change one bit until I seal it and go to an encapsulated space. I don’t see the advantage yet. But my insulation is basically nonexistent for the floor over the CS. And my duct work needs addressed. So it’s likely a 5-10k$ Project. And that’s one of the last places I want to spend money if I don’t have too.

 

[EatenByLimestone]

If you decide to do the encapsulation, decide what you want to do with the space. Now that it’ll be bright white, and clean, will you be storing stuff down there? It makes a difference on what product you use. The 10mil stuff is fine if you’re not going to be walking over it and dragging boxes, but won’t stand up to abuse.

There are different features that different brands have. Reinforcing fibers, anti mold coatings, etc. choos the product you want carefully. If having the work done, ask what product they’re using. It’s mostly labor expense, don’t let them install junk.

It’s not too hard to install the membrane. The flatter the floor, the better the outcome. Like painting and finishing work, prep is key. Getting the junk out is great advice.

We use a staple gun to help hold the top of the membrane to the sill plate. Once we get it laid out like we want it, we’ll go back and secure it to the masonry better.

Don’t skimp on the tape. It’s cheap. Any leftover tape will be used for other projects. It’s good tape!

They sell the membrane in many different widths. We use 3ft rolls. They’re easier to move around in small areas and through small hatches. Dealing with wide pieces, our supplier sells it up to 12 feet wide is a PITA. Unfolding and cutting around posts isn’t fun.

Wear a tyvek and full face respirator. In addition to the mold and such you often have the fibers from fiberglass insulation floating around, along with mouse, rat, or raccoon feces, etc. it’s a nasty place.

 

[mellow]

I do have mold issues, one of the things they are going to treat. No standing water in the crawlspace which is good but the old vapor barrier is just about non existent in spots now with me being under there doing a ton of plumbing and electrical work.

The basic vapor barrier is 6mil laid down and the encapsulated is using 10mil and sealed up, it is a VERY good price for either so I am on the fence on what I want to do, I am leaning towards just encapsulating it and being done with it for hopefully a long time. I have spent my fair share of time down there so I am not opposed to someone else doing the work this time around, I have plenty of other projects that need to get done anyway.

We have to run a dehumidifier in our living room where the piano is so my kids can practice, if we don't do that during the summer the keys stick so I am hoping that if I seal up the crawlspace and run a dehumidifier down there that issue and some others will go away. I ran the numbers on materials and the price I got for full encapsulation the guy isn't making a huge amount after paying labor so I am thinking that is the way to go, just wanted to see if others have done this and it is legit.

 

[VintageGal]

Thank you for the reminder! My crawl space is sloped and crawling around down there means I have to pull the vapor barrier back up and sideways! I will never need to encapsulate mine. It gets hot enough here in the summer that everything dries out pretty good by July.

 

[mellow]

Just to follow this up, after much research and deliberation I decided to go ahead and do the full encapsulation, not crazy about spending the $$ on something I will never see unless I am fixing stuff in the crawlspace but at least it will be clean now. I am hoping we won't have to run the dehumidifier upstairs anymore with one being in the crawlspace but we will see. Hopefully this will get rid of all the mold issues we have been having as well.

It is scheduled for later this week, will take several days to complete. Just glad it isn't me doing it for once.

 

[BigJ273]

Just keep in mind that the electric to run this dehumidifiers is not gonna be cheap. I think I estimated about $100 a month when I was looking into it. That’s for 2

 

[mellow]

Just keep in mind that the electric to run this dehumidifiers is not gonna be cheap. I think I estimated about $100 a month when I was looking into it. That’s for 2

Thanks for the heads up, I am only getting one and I will see if Sense picks it up to track it, if not I will throw a smart plug down there.

 

[Poindexter]

Late to the party. I did mine about three years ago. The main thing is my wife is very allergic to mold, so I was coming at this from a mold abatement perspective with no structural issues.

1. I left the old vapor barrier on the dirt at the floor of the crawlspace. I just could not find a good reason to take it up and pass it through a joist space, and then through the living spaces on its way to the dump. Why pay for someone to release even more mold into my living area?

2. My crawlspace is +/- 600 sqft, one dehumidifier was enough for me.

3. Options are very limited when gluing plastic to concrete in a damp environment. Local all I could get is "Acoustic tile sealant" aka "black death" with a MSDS and price to match. Don't get that stuff on your skin, and don't breathe the vapors coming off it.

4. While I was down there I pulled all the (moldy) insulation out of my rim joist spaces, and I honestly don't see a difference on my heating bill.

5. The outside of my poured foundation is spray on urethane foam, the bad stuff that was technically excellent when my house was built in 1980, but over decades absorbs water, loses R value and is tricky to remove. Someday I will rent a back hoe, scrape all that crap off, spray on the new latest greatest thing and backfill, or just sell the house.

6. I have two temp/humidity sensors in the crawl space, one at the incoming water line primarily for temperature, and one near the dehumidifier primarily for RH. Maintaining RH at 40% or less to minimize mold growth is not hard now that I have effective vapor barrier.

7. I put my vapor barrier on the footer of the poured foundation, not on the sill plates. If the joint burns down tomorrow and I get to start over, I will pull the existing foundation, and put an impermeable layer across the crawl space, under the new footings and up the outside of the new pour. Then I will have a thin layer of concrete poured in the floor of the crawl space. Then backfill and frame.

 

[mellow]

Thanks, the guys are finally starting work on mine this week. They are starting by spraying down everything twice to kill the existing mold then next week will start the rehab work once the existing mold is taken care of.

 

[mellow]

Got everything done and sealed up and the dehumidifier installed.
I went ahead and installed my HS110 last night so Sense can start tracking power to the dehumidifier and it is drawing a constant 420w of power, so by my napkin calculations at my current rates it will cost me $45/month or $545/year. Quite an energy hog, but if it works to keep the mold down then so be it.

I am kind of curious, I could set a schedule to have it turn off and turn on, once I have let it run for a few weeks nonstop I will look more into that if I can reduce use during the night or if during the day would be better? My power rates are fixed day or night, short of an increase happening this month.

 

[mellow]

I will also be installing a humidity sensor down there to keep track of things.

I was thinking about just getting an inkbird sensor and throwing it down there: https://inkbird.com/products/hygrometer-ibs-th2

 

[EbS-P]

That’s quite a bit of power. What RH is it set too? Have you given any thought to a washable pre filter?

Nice work.

Waiting for the “right” time to do mine but seeing RH values over 95% makes me think it should be sooner. But it’s been this way since 1968. No real issues that I can see yet.

 

[EbS-P]

I will also be installing a humidity sensor down there to keep track of things.

I was thinking about just getting an inkbird sensor and throwing it down there: https://inkbird.com/products/hygrometer-ibs-th2

I use these. Have two week onboard storage.
Govee Hygrometer Thermometer, Wireless Thermometer, Mini Bluetooth Humidity Sensor with Notification Alert, Data Storage and Export, 262 Feet Connecting Range https://a.co/d/d7IKZhm

 

[mellow]

That’s quite a bit of power. What RH is it set too? Have you given any thought to a washable pre filter?

Nice work.

Waiting for the “right” time to do mine but seeing RH values over 95% makes me think it should be sooner. But it’s been this way since 1968. No real issues that I can see yet.

It looks to be set at around 40-45% at the moment from the installer. Once I get my hygrometer down there I will be able to make a better informed decision on changing the settings.

I am hoping that the power use will be reduced once it gets things dried out down there, I am sure the wood is holding quite a bit of moisture that will take a while to dry out.

 

[gthomas785]

There's no way the 70 will run continuously forever. I have one in my crawlspace with much crappier encapsulation and I think it ran continuously for the first week or so as everything dried out but now it cycles. Set to 50% RH. I haven't been monitoring the energy consumption but I might start doing that.

 

[mellow]

There's no way the 70 will run continuously forever. I have one in my crawlspace with much crappier encapsulation and I think it ran continuously for the first week or so as everything dried out but now it cycles. Set to 50% RH. I haven't been monitoring the energy consumption but I might start doing that.

Good to hear, I will fiddle with the RH setting once everything evens out. It would be nice to get the dehumidifier below $20/month, about the same I pay for my pool filter running 24/7.

 

[mellow]

Things are starting to level out, the dehumidifier is running for around 8 minutes then shutting off for about 6 minutes so my costs have fallen. I now have a manual probe down there to keep track of things, it hovers around 45-47% the times I look at it.

My electric costs for the dehumidifier have dropped to around $25/month since I turned up the humidity from 40% to 45%.

 

[mellow]

One thing we have noticed is we do not have the humidity in the house we once had, we have not had to run the dehumidifier in the living room where the piano is located since getting the crawlspace done.

 

[EbS-P]

Things are starting to level out, the dehumidifier is running for around 8 minutes then shutting off for about 6 minutes so my costs have fallen. I now have a manual probe down there to keep track of things, it hovers around 45-47% the times I look at it.

My electric costs for the dehumidifier have dropped to around $25/month since I turned up the humidity from 40% to 45%.

View attachment 296981 View attachment 296982

I can’t keep my house below 50 with ac running all day let alone my crawl space.

 

[Rusty18]

Looking for opinions/confirmation but is that black mold on the blocks? Though it was just dampness until I got up to it, now I’m leaning towards I need to bleach it...

 

[gthomas785]

View attachment 297119
Looking for opinions/confirmation but is that black mold on the blocks? Though it was just dampness until I got up to it, now I’m leaning towards I need to bleach it...

I'm no encapsulation expert, but if that's going to be on the outside of your barrier then I'd think you don't need to worry about it. There's tons of mold and other fungus that lives in the ground anyway and it will just come back due to the high moisture level.

 

[mellow]

Looking for opinions/confirmation but is that black mold on the blocks? Though it was just dampness until I got up to it, now I’m leaning towards I need to bleach it...

I would have a pro come and look at it and they will use the appropriate chemicals on it and be able to figure out how it is growing and how to eliminate it come coming back.