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installing a vapor barrier

Crawl Space vapor barrier provides information about crawl space insulation.

Here’s a simple step-by-step guide to installing a high-quality crawl space vapor barrier in your home. These are general guidelines that will apply to all crawl areas. If you require additional assistance with more specific issues, please call us at 877-379-7658. In the following example, we’ll use a 12 mil crawl space vapor barrier.

Step 1: Examine your crawl space
Before beginning any work in your crawl space, you should evaluate all locations, conditions, and issues. This will help you subsequently understand what you’re up against.

Lighting is the second step.
Crawl Space LightingYou might not think that adding lights in your crawl space would be beneficial, but if you want to address your crawl space difficulties, good lighting will be a helpful tool in your efforts. Depending on the current state of your crawl area, I would recommend installing temporary lighting first and then wiring in a permanent solution once all moisture and water issues have been rectified. Crawl Space Light is a video about a crawl space work light that you could find handy.

Step 3: Clean up and preparation
Remove anything that isn’t dirt or linked to the house before installing a crawl space vapor barrier. Crawl spaces are frequently used as a dumping ground for construction and remodeling material; all of it must be removed to minimize odor, mold, and punctures. No matter how solid the crawl space vapor barrier is, sharp materials such as crushed rocks, broken concrete, and metal debris may cause punctures if they are not removed. If it cannot be removed or is simply too huge or many to remove, a protective underlayment such as the Felt 550TM can be used to protect your investment.

Step 4: Measure the size of your crawl space.
You can make educated guesses about what you need to save time, but when it comes time to spend your money, you must be precise. To obtain a good idea of what you’ll need for water control, start with a crawl space vapor barrier and a crawl space dehumidifier. You will require the following details.

the whole length of your foundation walls
the total height of your foundation walls
the location of your crawl space’s lowest point
the location of your crawl space access
your access’s size
Do you have any issues with water? Have you ever seen ANYTHING standing in the crawl space? Are the foundation walls stained?
Is there air conditioning in your house?
Do you have foundation vents to the outside in your crawl space?
Make a drawing of your crawl area using this information. This graphic will help you plan and execute your crawl space project.

Step 5: Choose a Product

Refrain from making Step 5 the first step. Here’s why: instead of making the products fit the crawl space, choose products that solve the crawl space. Most people are concerned about cost, but if you choose a crawl space vapor barrier based solely on price, you will get what you paid for. Worse, you may overpay for a low-cost product believing it to be superior because a reseller refers to an 8 mil thick vapor barrier as a 20 mil thick vapor barrier to make their pricing appear CHEAP. Our proposal presupposes that the reader wants their work to last as long as possible, that product quality is important, and that outcomes are essential. The recommendation can be found at this link: Vapor Barrier Selection. Now it’s time to get grizzly and address the problem under your house. The following are the final five installation steps…

Crawl Space Liner Installation at Home
6th Step: Tools
I’m sure you already know this, but I’ll say it again: having the correct tools makes ANY endeavor so much easier, faster, and less expensive. Consider the following tools:

shovel for crawl spaces
pick axe for crawl space
knives for crawl spaces
blades replacement
100-foot tape measure
drill with a hammer (not a drill with a “hammer” feature)
saw that reciprocates (for plumbing work, cutting roots and buried debris)
driver of screws
hammer
wire staples
GFI electrical cords
Lights for Crawl Spaces
respirator
organic mold remover
broom for crawl spaces
small vacuum cleaner
Paper towels for heavy workshops
Step 7: Build the foundation walls
This is the area with the biggest variation in installation processes from one provider to the next. I’ll explain how we do it, and then you can compare it to the numerous different variations. Some of the alternative approaches appear to be faster and better on paper, but they do not work in practice. My sample crawl space will be a rectangle, 30 feet wide, 60 feet long, and 4 feet 3 inches high, with 12 Mil GuardianLinerTM installed. In the technique we advocate, you will install the walls first, but you must first decide out how your flooring will lay. Facts:

In our case, the crawl area is 30′ broad.
The GuardianLinerTM is 13’4″ long “wide.
The floor seam should overlap 10-12 times for the greatest effect.”
To cover the floor breadth we will need 2 pieces of GuardianLiner™ with a width of 13’4″ side by side
We can cover 25’8″ with 13’4 + 13’4 = 26’8″ without the 12″ lap seam “of floor width with two GuardianLinerTM pieces
We have a crawl space that is 30′ wide and 25’8 deep “crawl space vapor barrier to be installed on the floor
We are 4′ 4″ short of covering the complete width of the floor after subtracting 30′ from 25’8″.
Here’s why we need to know the floor layout before we start cutting the walls: now that we know how short our floor piece is from reaching all the way across the crawl space, we can make our wall pieces longer to cover the missing floor piece. We recommend hanging the wall pieces like wallpaper, in other words, the 13’4″ x 13’4″ x 13’4″ x 13’4″ x 13’4″ x 13’4″ x 13’4″ x 13’4″ x 13’4″ “The width will be at the top and bottom. Instead of one giant component, you will have numerous smaller bits to manage. The length of the wall section will be equal to the height of the wall (minus 3) “termite inspection gap)+ floor overlap + whatever the short floor piece is

Our wall height is 4’3″, minus 3″ for the termite inspection gap, and we are left with; 4′ wall height+ 2’8″ floor piece we are short + 12″ floor lap= 7’8″ wall lengths. Wall seams should be 4″ to 6″ overlap (between each wall component). This will not be an even number, but this is how you calculate how many wall components you need.

Our crawl area is 30′ wide and 60′ long, thus our perimeter is 180′ around it. To determine how much crawl space vapor barrier to cut, divide (13’4″ minus 4″ overlap) by 180′, which equals 13.8 wall pieces. You will cut 14 7’8″ wall sections, and because we left 4″ for the wall overlap and there is extra, you can make the wall laps wider than 4 inches ” (you have the extra material in the 14 pieces).

Make ALL of your cuts outside and then bring them into the crawl space; it’s much easier, faster, and cleaner. Before you cut, consider this: If the floor is 2’8″ shorter than the ceiling, “On the sides, shorten the length by the same amount at both ends. Here’s why: with a flat crawl area with the same wall height all around, you can make all the wall sections the same length (here 7’8”) “) without having to make adjustments at both ends with a shorter piece.

It doesn’t matter if it’s from the floor or the walls because you’re going to seal it with seam tape. Another reason is that the greater the distance between your tape seams and the foundation wall, the easier it is to tape. It will be much easier for you to seal the seams if you tape 2’8″ away from the foundation wall all the way around the crawl space, so your floor pieces would be 54’6″ long in this case. This will leave a 2’8″ space at the ends, matching the 2’8″ gap on the sides.

Another thing to think about before you cut is cutting both floor pieces first, then making the wall pieces from what’s left over. In our example, we want two 54’6″ long floor sections made from one piece (no splices), which will require three 13’4″x75′ long rolls of GuardianLinerTM to finish if done correctly. If you first cut ALL of the wall parts, one of your floor halves will be in at least two pieces, not just one. Here’s how it works: 14 7’8″ wall sections “Long equals 108′ of material.

You will obtain 9 wall pieces from one complete roll and 5 wall parts from another roll, which will require 38’4″ “from the 75-foot roll That roll is now 36’6″ long, and you need 54’6″, so take the 20’4″ from the other floor piece (75′ long minus 54’6″ = 20’4”) and tape it to the end of the other floor piece to get the length correct. It’s not a major concern in terms of function because you’ll tape the two together, but when it happens, you’ll kick yourself for not cutting the floor pieces first.

Brush (not wire brush, simply sweep) the foundation wall at the top where the crawl space vapor barrier will be attached to remove loose dirt and spider webs. Install the Foundation Seal TapeTM along the foundation wall’s perimeter. If the foundation is really wet, you may need to use Poly Caulk. After the wall pieces have adhered to the Foundation Seal Tape and the flooring have been attached to the walls, the Foundation PinsTM can be installed. Installation videos for Foundation Seal TapeTM and Foundation PinsTM may be found at the bottom of this article.

Floor (Step 8)
There isn’t much else to say here. One advantage of splitting the crawl space vapor barrier floor width shortage to equal amounts on each side is that your center seam will meet at your row of support columns, making cutting around them much easier. Keeping the vapor barrier pieces square to the crawl space and removing your shoes can make cleanup easier later. Here’s a video showing how to build a crawl space vapor barrier in real-time. Simply click here.

Step 9: Tape
Taping a Crawl Space Liner
The Waterproof Seam TapeTM is designed to operate with the aforementioned crawl space vapor barriers and will not come loose when exposed to water, which is critical because many “crawl space tapes” do. Take your time and sure to tape the crawl space vapor barrier square to the crawl space.

Step ten: Condition the air
Dehumidifier for Crawl Spaces
Conditioning a crawl space can be done in a variety of methods; the key thing is to DO IT. Conditioning a crawl space is a reason the crawl space is required to be encased, therefore don’t skip this step to save money. Would you buy a pool and not fill it with water because it was not included in the price, or would leaving it out make the pool less expensive? Conditioning can be accomplished utilizing either a high-quality crawl space dehumidifier or your existing air conditioning unit. Both options have advantages. Obtaining a moisture management plan for your crawl space is the best approach to determine which is ideal for your property.

Crawl Space Makeover can assist you with professional crawl space vapor barrier installation.

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