It is worth stating that "humidity" (relative humidity) changes as a function temperature and dew point. If the crawl space temperature is lowered (raised), the humidity will increase (decrease) because moisture content (dew point) of the air is the same. Just because the outside air humidity is high in low temperatures does not mean that air has a high moisture content (high dew point). I think the best explanation for increased humidity in crawl spaces after encapsulation (assuming the temperature is kept constant) is wood framing is releasing moisture into the the closed (encapsulated) crawl space (your #1 explanation); with moisture moving from the wood to the crawl space air, the humidity will increase. Over time as the dehumidifier removes moisture, the wood will slow its release of moisture into the crawl space lowering the humidity and/or the dehumidifier will work less.
I don't usually comment on RUclips videos but, I would like to shout out to these guys for spreading this knowledge, I'm halfway through a crawl space encapsulation and I feel like I actually know what I'm doing, lol! Thanks for all the work you put into this channel!
Thanks so much for the support! So glad to hear our videos have been helpful to you. Feel free to share your project with us through Ask A Ninja, we may even feature it! crawlspaceninja.com/ask-a-ninja/
This is why when I encapsulated mine, I 1st ripped everything out, soda blasted, sealed vents and ran a dehumidifier and exhaust fan for one month before starting on encapsulating. I checked wood moisture and the looseness of the soil. Worked like a charm.
Is the spike in humidity after encapsulation temporary? By the way I've been watching your videos for the last year. I find them very helpful and informative. I've recently purchased an Aprilaire dehu and a condensate pump from Crawl Space Ninja and I couldn't be happier with the speed of delivery and the exceptional customer service. Mary Beth has been my main contact.
We recommend it if you're doing an encapsulation, but you have to be careful how you install it. Here are a couple videos talking about insulating them and showing how to attach the vapor barrier to the insulation: ruclips.net/video/369yfSqPvP8/видео.html ruclips.net/video/ZzsgvkjRHfQ/видео.html
SEALING THE FOUNDATION VENTS: With a brick home would it be advisable to only seal the vents on the crawl space side. Reason being, leaving the outside vents open would allow air flow between the brick and wall sheathing.
Micheal, I've heard you mention many times take care of the humidity first and foremost right,even before installing the plastic, insulation or even the french drain? Once the humidity is under control, would the sealed vents,sealed crawl space door and a good vapor barrier on just the ground be enough to keep the humidity under control?
I just finished a DIY encapsulation. I did not start the process until the dehumidifier was installed. The dehumidifier ran for the first 36 hours non stop after the crawlspace was sealed. As time goes on the dehumidifier has been running less and two weeks later the dehumidifier is running about 50% of the time. How often should the dehumidifier have to run in a sealed crawlspace in a humid area?
That is a great question and one I do not have a definitive answer for. The best answer I have is it depends and as needed...so sorry I can't be more helpful than that. Thanks for watching.
Just giving an update. The humidity outside has been high but my crawlspace is dry and the dehumidifier is barely running. I installed an energy monitor and at first the dehumidifier was running for 10-12 hours per day. The daily runtime has been decreasing but seems to be between 1.5 to 2 hours a day now.
its funny houses that are vented never smell musty... because u can nver have musty smell with free movement of fresh air.. check houses on pillars... i only learn from British folks since there homes are built better and their homes are much much older so they know a thing or two
It is worth stating that "humidity" (relative humidity) changes as a function temperature and dew point. If the crawl space temperature is lowered (raised), the humidity will increase (decrease) because moisture content (dew point) of the air is the same. Just because the outside air humidity is high in low temperatures does not mean that air has a high moisture content (high dew point). I think the best explanation for increased humidity in crawl spaces after encapsulation (assuming the temperature is kept constant) is wood framing is releasing moisture into the the closed (encapsulated) crawl space (your #1 explanation); with moisture moving from the wood to the crawl space air, the humidity will increase. Over time as the dehumidifier removes moisture, the wood will slow its release of moisture into the crawl space lowering the humidity and/or the dehumidifier will work less.
Agreed
I don't usually comment on RUclips videos but, I would like to shout out to these guys for spreading this knowledge, I'm halfway through a crawl space encapsulation and I feel like I actually know what I'm doing, lol! Thanks for all the work you put into this channel!
Thanks so much for the support! So glad to hear our videos have been helpful to you. Feel free to share your project with us through Ask A Ninja, we may even feature it! crawlspaceninja.com/ask-a-ninja/
This is why when I encapsulated mine, I 1st ripped everything out, soda blasted, sealed vents and ran a dehumidifier and exhaust fan for one month before starting on encapsulating. I checked wood moisture and the looseness of the soil. Worked like a charm.
Thanks for sharing!
Is the spike in humidity after encapsulation temporary? By the way I've been watching your videos for the last year. I find them very helpful and informative. I've recently purchased an Aprilaire dehu and a condensate pump from Crawl Space Ninja and I couldn't be happier with the speed of delivery and the exceptional customer service. Mary Beth has been my main contact.
I have a question what do you think of vapor barrier on stone wall foundation
We recommend it if you're doing an encapsulation, but you have to be careful how you install it. Here are a couple videos talking about insulating them and showing how to attach the vapor barrier to the insulation:
ruclips.net/video/369yfSqPvP8/видео.html
ruclips.net/video/ZzsgvkjRHfQ/видео.html
What type of dehumidifier do u recommend?
We always recommend Aprilaire dehumidifiers!
Can i use a dehumidifier from Walmart? What's the best part of the crawl space to put it in?
How long should it take to get humidity down after doing an encapsulation?
It depends on what is done and if it was done properly. Ideally you will want it down within 48 hours.
SEALING THE FOUNDATION VENTS: With a brick home would it be advisable to only seal the vents on the crawl space side. Reason being, leaving the outside vents open would allow air flow between the brick and wall sheathing.
Micheal, I've heard you mention many times take care of the humidity first and foremost right,even before installing the plastic, insulation or even the french drain?
Once the humidity is under control, would the sealed vents,sealed crawl space door and a good vapor barrier on just the ground be enough to keep the humidity under control?
It would help, but those things alone will not remove existing humidity. We still recommend always having a dehumidifier.
I just finished a DIY encapsulation. I did not start the process until the dehumidifier was installed. The dehumidifier ran for the first 36 hours non stop after the crawlspace was sealed. As time goes on the dehumidifier has been running less and two weeks later the dehumidifier is running about 50% of the time.
How often should the dehumidifier have to run in a sealed crawlspace in a humid area?
That is a great question and one I do not have a definitive answer for. The best answer I have is it depends and as needed...so sorry I can't be more helpful than that. Thanks for watching.
Just giving an update. The humidity outside has been high but my crawlspace is dry and the dehumidifier is barely running. I installed an energy monitor and at first the dehumidifier was running for 10-12 hours per day. The daily runtime has been decreasing but seems to be between 1.5 to 2 hours a day now.
its funny houses that are vented never smell musty... because u can nver have musty smell with free movement of fresh air.. check houses on pillars... i only learn from British folks since there homes are built better and their homes are much much older so they know a thing or two