DIY Crawl Space Guide: Vapor Barrier Removal Week 8

Timing is everything when it comes to successful crawl space encapsulation, especially when tackling old vapor barriers and hidden debris. This deep dive into Week Eight of our Crawl Space Repair Challenge reveals why patience pays off and rushing could sabotage your entire project.

Most DIYers and even some contractors make the critical mistake of ripping out old vapor barriers on day one. I'm showing you why this strategic delay actually accelerates your overall project success. By maintaining that old plastic during the initial drying phase, your dehumidifier can focus exclusively on reducing wood moisture (targeting 15% or less) rather than fighting a losing battle against constantly evaporating soil moisture. The existing vapor barrier also provides a cleaner work environment, protects your equipment, and prevents excessive dust during early repair stages.

The removal process itself addresses one of the most common complaints in crawl space work – that mysterious "cat pee smell" that sometimes develops after encapsulation. I explain how hidden contaminants beneath seemingly clean plastic (from old plumbing leaks to organic matter) can create this issue, and why complete removal is non-negotiable. You'll also learn the critical window between removing old materials and installing new ones to prevent re-contamination of dried structural wood.

Your timing doesn't end with removal, though. I share strategies for maximizing efficiency during the drying period, including installation of foundation insulation barriers and water management systems to maintain momentum in your encapsulation project. Whether you're handling this as a DIY weekend warrior or vetting professional contractors, understanding these strategic timing elements transforms your crawl space from perpetual problem to permanent solution.

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Episode Transcript

Speaker 0 (00:00):
Hey, michael Church, crawl Space Ninja.
We are on week eight of theCrawl Space Repair Challenge and
today I want to go overremoving old vapor barrier and
debris that is located under thevapor barrier.
What is the importance of thisstep in the Crawl Space
Encapsulation Project?
Some things we'll be coveringin this video include why am I

(00:20):
asking you to wait this long inthe Crawl Space Encapsulation
Repair Project before you removethe vapor barrier?
Some people want to remove thevapor barrier as a step one and
I'm having you wait, so why am Iasking you to do that?
What are some things that youneed to know before removing
that vapor barrier and debris?
Preventing cat pee smell why isthat important?

(00:41):
The timing of not waiting toolong between removing the debris
and the next step, and thenmaking use of your drying time.
I encourage you, if you havenot already, make sure you check
out week two and week three ofthis video series.
They go hand in hand with thisvideo and I know that we're on
week eight.
I'm not saying it takes youeight weeks to get to this step.

(01:03):
If you're doing crawl spaceencapsulation, we're just taking
each of the steps and making anew video for each step.
This could be done in as littleas four days.
We do 2,000, 3,000 square footcrawl space encapsulation
projects in a short amount oftime.
But most people can't get itdone in that amount of time
because, of course, we've gottwo to three ninjas doing it and

(01:24):
we've been doing it for a longtime.
So if you're looking to DIYthis project yourself, this is
the steps that it would take inorder to do that.
Or if you're looking to hire acontractor, these are the steps
that we recommend that are takenduring the encapsulation
process to make sure that it allgoes very smooth.
Why wait until now to remove thevapor barrier?
Why wait until now to removethe vapor barrier?
Well, basically, we needed thewood to dry out.

(01:44):
As I talked about in week twoand week three, part of the
phase one process is gettingthat wood to dry.
So I want all of that wood todry out.
Another thing is leaving thatplastic down gives that
dehumidifier the ability to dryout the wood without drying out
the soil.
If I was to remove the plasticon phase one, day one, then that

(02:06):
dehumidifier is going to befighting to dry the soil and the
wood and normally there's morewater in the soil so the wood
takes longer to dry.
It's also going to make thecrawl space less dirty so that
you can crawl around and dothings.
If it's a really dry crawlspace, for example, you're going
to be kicking up a lot of dustif you don't have that plastic
down on the ground.
So leaving that plastic doesmake it less dusty in the crawl

(02:30):
space and it's going to protectyou.
If you do have a flooded crawlspace, if it's real muddy down
there, that plastic is going tohelp protect you as you maneuver
and do some of the stepsinvolved in encapsulating the
process and, believe it or not,it'll actually keep that
dehumidifier clean, which isreally nice.
So if you've got thatdehumidifier that we talked
about in step two and three ofthe process, then you want to

(02:53):
make sure that filter staysclean so that that dehumidifier
gets that crawl space dry andworks efficiently.
So these are some of the reasonswhy you would want to leave the
vapor barrier in place up untilthis moment.
Before you remove that vaporbarrier, I want you to make sure
that the moisture levels in thecrawl space are in good shape.
I would like for that humidityto have been kept under 60% up

(03:17):
until this point so that itcould dry out that wood, and I
would like to see that woodmoisture level around 15% or
less.
This is actually too high at53% that's pegging my meter,
which is why we've started theprocess of getting the crawl
space dry up until this point.
So make sure you check themoisture readings in the crawl
space before you remove thatvapor barrier, because once you

(03:39):
remove it, that dehumidifierthat's been working for a little
bit is going to try to dry theground.
This is one of those phaseswhere you can avoid that cat pee
smell that we hear everybodytalking about so much.
So basically, as you can see inthese two images, I've got a
nice looking plastic on the leftand I've got bare dirt on the
right.
So if you were to put new vaporbarrier over this old plastic,

(04:03):
even though it looks really good, there could be debris, there
could be some wood trapped underthis plastic.
Perhaps you had an old plumbingleak that you were unaware of
from the washing machine andthat gray water made it down
into the crawl space on top ofthe old vapor barrier.
So I would rather you removethe old plastic and any debris

(04:24):
under that plastic that couldgrow mold or bacteria, because
that could also cause a that wasoriginally installed in the
crawl space or one that's beenin there long enough to get
something on top of it, like Imentioned, where the washing

(04:50):
machine flooded or maybe ananimal died in there or
something like that.
So make sure you get all ofthat vapor barrier and the
debris under it out as part ofthis process.
Don't leave the dirt exposedtoo long.
In other words, after you takeout the vapor barrier, I want
you to move to the next phase inthe crawl space encapsulation,

(05:12):
which will be next week's video.
As soon as you pull that vaporbarrier out, we're going to move
to week nine's video, so I'lllet you know when that video
comes out.
I'm not going to share with youwhat it is yet, but don't wait
too long, because if you leavethat dirt exposed and that
dehumidifier has been installed,trying to keep that crawl space
dry, that dirt could actuallyre-infect the wood.

(05:36):
Now it won't look as bad asthis picture here.
I'm using this more fordramatization, but basically you
want to make sure that youremove that plastic before
moving to week nine's video, butdon't leave too much time left.
We were installing insolebarrier while that old vapor

(06:06):
barrier was installed.
So the dehumidifier is workingand drying out the crawl space.
We had some time.
We're utilizing our time well.
We are going ahead andinstalling that insole barrier.
Now, this particular crawl spaceon the left did not have a lot
of high wood moisture levels, sowe left the insulation between
the joists have a lot of highwood moisture levels, so we left
the insulation between thejoists.

(06:27):
That was per the homeowner'srequest.
We didn't see a lot of mold, sothey wanted to leave that
fiberglass in place, so that wayit could be a benefit to
insulate the subfloor as well asthe foundation walls.
Once we sealed the vents andthen, obviously on the right,
you could go ahead and startinstalling that water management
system using that Hydrawaysystem on the right.

(06:47):
So there are some things thatyou can do in order to maximize
your time while the crawl spaceis drying out.
So these are some good thingsthat you can do.
As I've mentioned in many of myvideos, we've got our book Crawl
Space Repair Myths Bustedlocated on Amazon.
If you get a chance to checkthat out.
If you'd like to do aconsultation with me, you can do

(07:08):
that at buymeacoffeecom and, ofcourse, we hope you'll like and
subscribe to our channel.
Let me know down in thecomments what you think of this
series so far.
Really appreciate your feedback.
I'm Michael Church with CrawlSpace Ninja.
We hope you make it a happy andblessed day and we'll see you
later.