DIY Crawl Space Encapsulation on a Budget: Project Overview

Project Length: 1 Week

Total Cost: $2025.21

Project Cost Breakdown:
All supplies were purchased from Amazon, Lowe's, and crawlspacevaporbarrier.net. 

• 3M 6000 Series Half Facepiece Respirator, Medium $25.21
• 3M Standard Hard Hat $9.98
• AWP Nylon-Cap Knee Pads $10.98
• Pactiv Extruded Polystyrene Foam Board Insulation  $16.98
• Rust-Oleum 15-oz Black Flat Spray Paint $5.27
• Dow Great Stuff Gaps and Cracks Insulating Foam Sealant 12-oz (5 cans) $18.40
• Warrior Roofing 30 Lb Felt Quality Roof Deck Protection (4 rolls) $75
• Blue Hawk 75-Pack 4-in Steel Landscape Fabric Pins $9.98
• Foundation Seal Tape™ for Crawl Spaces (2 rolls) $51.98
• 12 Mil Vapor Barrier for Crawl Spaces, GuardianLiner™ (2 rolls) $500
• Hilti TE 10 rotary hammer drill (purchased from local pawn shop) $50
• Bosch 1/4-in x 4-in SDS-Plus Drill Bit $16.76
• Crawl Space Foundation Pins $19.99
• Encore Plastics 5-Gallon Lowe's Bucket with 2-in Plastic Bucket Lid $4.06
• Waterproof Seam Tape™ for Crawl Space Vapor Barrier (3 rolls) $98.97
• Premium Polyurethane Caulk (4) $27.20
• Crawl Space Dehumidifier | Compact Air Plus $999
• Basic Connections 25' 16/3 Extension Cord $9.68
• Gardner Bender 50-Count 3/4-in Plastic Insulated Cable Staples $2.78
• Oatey 8-fl oz LO-VOC PVC Cement and Primer $8.48 
• LASCO 3/4-in Dia PVC Sch 40 Adapter $.46
• LASCO 1/2-in and 3/4-in Dia PVC Sch 40 P-Trap $2.07
• LASCO 3/4-in Dia 90-Degree PVC Sch 40 Slip Elbow (3) $.90
• LASCO 3/4-in Dia PVC Sch 40 Coupling (7) $1.89
• Charlotte Pipe 3/4-In x 5-Ft 480 Psi Schedule 40 Pvc Pressure Pipe (6) $12
• Kobalt 1-5/8-in PVC Cutter $11.89
• AMERICAN VALVE 120-in L Galvanized Hanger Iron $2.83

Resources:

Crawl Space Encapsulation: The Method by Energy Vanguard 

DIY Crawl Space Encapsulation on a Budget: Day 7 - Install Drain Line

Supplies:

• Vise-grip
• 3/4" PVC threaded connector
• 3/4" PVC trap
• 3/4" PVC elbow (3)
• 5' x 3/4" PVC pipe (6)
• 3/4" PVC connectors (7)
• Oatey 8-fl oz LO-VOC PVC Cement and Primer
• Kobalt 1-5/8-in PVC Cutter
• Hammer drill
• Bosch 5/8-in x 12-in Round Hammer Drill Bit
• Great Stuff 
• Scrap piece of vapor barrier
• White seam tape
• Level
• AMERICAN VALVE 300-in L Galvanized Hanger Iron
• Scissors
• Staple gun

The PVC section at Lowe's is a bit overwhelming for a novice like me, but there was a knowledgeable employee that was able to help me find everything I needed for the drain line. When I got home, I began piecing together 5 pieces of the 5' long 3/4" PVC pipe by applying the primer and cement according to the instructions. I then screwed in the threaded connector using my vise-grip. From there I connected an elbow, drain trap, and the long section of pipe to take the water from the dehumidifier outside.



Lowe's did not have a 12" x 1" drill bit in store, so another helpful sales associate in the tools department talked me into getting a smaller drill bit and making a series of holes in order to get the opening I needed to put the drain line through the foundation. I selected the drill bit that was on clearance and ended up spending about 30 minutes drilling. The hole looks really good, smooth, and surprisingly round from the exterior. While economical, this method was a terribly inefficient way to drill a 1" hole.

After I drilled the opening in the foundation, I fed a piece of pipe through into the crawl space. Before connecting it, I cut a scrap piece of vapor barrier to cover the space around the hole and a cut a star in the middle of the scrap piece to put the pipe through. I then connected the pipe using the primer and cement. I sealed around the hole from inside the crawl space using Great Stuff. After that dried, I used the white seam tape to apple the scrap piece of vapor barrier to the wall and seal around the pipe.

I used a couple of PVC elbows and short sections of pipe to lead the water away from the foundation.

Finally, I cut sections of hanger iron to support the pipe from the dehumidifier all the way down to the end of the house. I fastened the hanger iron to the joists using a staple gun, and I used a level to ensure that there was enough of a slope all of the way down.

DIY Crawl Space Encapsulation on a Budget: Day 6 - Install Dehumidifier

Supplies:

• Compact Air Plus- Crawl Space Dehumidifier
• 25 ft outdoor extension cord
• cable staples
• hammer
• power drill and drill bit
• 5 gallon bucket

This was the one day when I had to get help from my husband. I knew there was no way I would be able to lift the dehumidifier in the crawl space in order to hang it from the joists. Before I asked for his assistance, I chose the most central, yet convenient location for the dehumidifier. I plugged in an extension cord and tacked it up along the joists as I stretched it over to the other side of the crawl space. I will eventually have an electrician come and put an outlet close enough to the dehumidifier to eliminate the need of an extension cord, but since we already had outlets down there for the previously installed vent fans, I am putting that off for a little while. The last thing I did was install the hang kit that came with our dehumidifier. It was then time for my husband to do the heavy lifting.

I know that a drain line should be installed, but I also know that it will probably take me a long time to do it given that I have zero plumbing experience. I am getting nervous about the humidity in the crawl space since I sealed it up. The hydrometer that I have down there shows the moisture level has risen to 80%. I used the vinyl hose that was included with the dehumidifier, tied it in a knot to form a trap, and put the hose through a hole in the lid of a 5 gallon bucket.

DIY Crawl Space Encapsulation on a Budget: Day 5 - Seal Vapor Barrier

Supplies:

• Waterproof Seam Tape™ for Crawl Space Vapor Barrier (3 rolls)
• Great Stuff foam insulating sealant 
• Pactiv Extruded Polystyrene Foam Board Insulation (Common: 1-in x 4-ft x 8-ft; Actual: 1-in x 4-ft x 8-ft)

My project today was pretty straight forward. I used a little more than 2 rolls of the white seam tape and sealed the walls, the walls to the floor, and the floor to the piers. As I stretched out the tape, I pressed it firmly into the surface to ensure a good seal.

Sealing the corners of the piers was very time consuming and required a lot of tape. One reason it took so long was because the duct work runs along side the piers, making it very difficult to work around them. The reason it took so much tape was likely due to my lack of skill and also the unevenness of the ground. The ground around each pier is several inches lower than the rest of the crawl space floor.

The last thing I sealed was the wall around the air conditioner. Our house was built in the 1950's, before central heat and air. Because of this, a huge hole was later busted out of the foundation in order to install the ductwork. The hole is 2-3' tall and wide, incredibly messy, and has two huge ducts going through it. I noticed that I could see light coming in from outside where the air conditioner meets the house, so I sealed as much as I could with Great Stuff. I then used a leftover piece of foam board to fit the opening and filled the remaining gaps with Great Stuff. Finally, I used some scraps of the vapor barrier and seam tape to make it as airtight as possible.

DIY Crawl Space Encapsulation on a Budget: Day 4 - Fasten Walls And Lay Floor

Supplies:

• Hammer drill
• 1/4" masonry bit
• Crawl Space Foundation Pins
• Rubber mallet
• Retractable safety knife

This is the part of the process that I was most nervous about. First of all, a cordless hammer drill is an expensive piece of equipment. Second, they have a lot of power. Third, I would be putting 70 holes in my foundation with this thing. I ended up getting a very used Hilti TE 10 Rotary Hammer Drill for $50 at a pawn shop. I was shocked at how easy this thing was to use. In fact, I had those 70 holes drilled and the walls fastened in place with the foundation pins in less than an hour.

I began at the far end of the crawl space and drilled holes every two feet at the top of the vapor barrier along the foundation tape. I fastened each corner with two pins, one pin on each wall about one foot from the corner. I tapped the pins in with a rubber mallet.


Laying the floor was difficult because of the size of the sheets (13' x 45') and the fact that I was working alone. I rolled the first sheet to the far corner of the crawl space and unrolled it. The vapor barrier was folded in half, so after I unrolled it, I had to unfold it.

I went through the same steps with the other sheet on the opposite side of the crawl space. In addition to unrolling and unfolding, I also had to cut the vapor barrier so that I could later seal it around the piers.

DIY Crawl Space Encapsulation on a Budget: Day 3 - Cut Vapor Barrier, Hang Walls, and Wrap Piers

Supplies:

• 12 Mil Crawl Space Vapor Barrier, GuardianLiner™ (2 rolls)
• Tape measure
• Retractable utility knife
• Sharpie 
• Tape
• Hard bristled brush
• Foundation Seal Tape™ for Crawl Spaces- Made in the USA! (2 rolls)

Today I finally worked on installing the new vapor barrier. The first few hours were spent during the day rolling out two huge 13' x 75' sheets of plastic and cutting them to fit the space. Of course, I already knew the dimensions of my crawl space, so I drew up a plan. My crawlspace is 25' x 45' with five piers running down the center. I cut 45' off of each roll, giving me two sheets 13' x 45' to cover the floor on either side of the crawl space. I cut the remaining 30' of each roll into 6 4' strips. I used 5 of these to cover the walls, and I cut the last one into 6' x 4' sheets to wrap the piers. I made sure that each piece was cut generously enough to allow for a 12" overlap.

I was incredibly nervous to cut into this expensive material, so I triple checked every measurement. As I made each cut, I labeled the piece, rolled it up, taped it, and set it aside. When all pieces were cut, I put them all into the crawlspace for later.

Hours later, after my kids were in bed, I went back to work. I used a hard bristled brush to remove dirt and dust from the foundation walls.

I then applied black foundation tape to the walls 3-4" from the top of the block. Most resources that I found online recommended this gap in order to allow for future termite inspections. Finally, I carefully applied the vapor barrier to the block. I left about an inch of the vapor barrier above the tape so that I could later add some caulk. I recognize that using both caulk and foundation tape is overkill, but I couldn't choose between the two.

The foundation tape came with a paper backing, and I only removed a short section of the tape at a time.  It was pretty difficult to manage the 30' long sections. It was easier to keep the material straight if I worked with 3" or so at a time, but I often rushed through and ended up with some wrinkles. Also, as I adhered the vapor barrier onto the foundation tape, I used the back of my utility knife to make sure it would hold.

I wrapped the piers in much the same way except that the sheets had to be cut at each corner.

DIY Crawl Space Encapsulation on a Budget: Day 2 - Prepare for New Vapor Barrier

Supplies:

• Garden rake
• Retractable safety knife
• Landscape fabric pins
• Warrior Roofing 30 Lb Felt Quality Roof Deck Protection (4 rolls)

My goal for the second day of this project was to prepare for the new vapor barrier. This was a very dirty job but not at all difficult. It was pinned in place, but I easily removed it and pulled it out of the access door, and had it taken off with the trash. I then raked the entire crawl space to clear rocks and other debris using a regular garden rake. This was difficult, and I still wasn't pleased with the results several hours later.

I decided at the last minute to pick up some felt paper to lay under the new vapor barrier. I had seen underlayment used in several online tutorials and noticed different types available on several crawl space product suppliers' websites. It is typically recommended for crawl spaces that will have a lot of traffic or be used for storage. I chose to use Warrior Roofing 30 Lb Felt. I do not know how this product differs from the felt underlayment that is manufactured specifically for crawlspaces, but I felt that it would provide cushion and protection. Furthermore, having the felt on the floor would provide a nicer and much cleaner work environment until I laid the floor down. This task was quite simple. I rolled the felt to the far end of the crawl space, pinned one end using landscape fabric pins, rolled it out, and repeated until the entire floor was covered.

DIY Crawl Space Encapsulation on a Budget: Day 1 - Seal Vents

After a musty smell began to work itself up from the crawl space and into our home, we knew that something had to be done. We got estimates from three reputable companies that specialized in crawl space repair. Prices ranged from 5-8k. While we weren't happy about the expense, we were especially frustrated that each company had very different recommendations. After spending countless hours researching the problem and various solutions, I decided that I'd just take care of it myself. I am going to publish my progress so that others may benefit from my experience.

Gear:

• Petzl E91 Tikkina 2 Headlamp
• Hard hat
• Safety goggles
• 3M 6000 Series Half Facepiece Respirator, Medium
• Long-sleeved t-shirt
• Jeans
• Kneepads
• Rain boots 

I only needed to see what I was looking at, so a headlamp was sufficient. The hardhat was a must because we have nails sticking out all over the ceiling of the crawl space. I only wore the safety goggles when using Great Stuff. I used a good respirator because it is musty in the crawl space and I am going to be working in the dirt after I remove the current vapor barrier.  I wore long sleeves and jeans because it's a dirty job. The kneepads made the job much more pleasant since I spent most of my time crawling. Finally, I wore my rain boots because they could be easily hosed off.

Supplies:

• Pactiv Extruded Polystyrene Foam Board Insulation (Common: 1-in x 4-ft x 8-ft; Actual: 1-in x 4-ft x 8-ft) 
• Flat black Rustoleum 
• Great Stuff Insulating Foam Sealant

I purchased 1 sheet of foam board from Lowe's and spray painted one side with flat black Rustoleum. From inside the crawl space, I started at one end and made my way around removing screens and vent fans and noting the dimensions of each opening.

As I made my way to the back of the house, there were several unique circumstances. One opening was covered with plumbing including a drain line from the water heater that exits the home through the crawl space vent. The other unusual opening was partially covered with an extra floor support that prevented me from being able to remove the current vent screen from inside the crawl space. 

After getting measurements, I went outside and cut the foam board with a retractable utility knife and labeled each one. Before going back under the house, I sealed the two previously mentioned openings from the exterior. Despite taking measurements first, nearly every piece of precut foam board had to be trimmed. After fitting it in the opening, I sealed it with Great Stuff insulating foam sealant.

It turns out that Great Stuff is a mess! I should have practiced using it in the crawl space. Instead, my first disaster is clearly visible for all to see. I am still not sure how I will clean it up, but I am sure that it is sealed.

Most of the openings had two screens, one inside and one mounted outside. As mentioned earlier, I removed all of the interior screens that I could access, but I left all of the exterior screens. From the exterior, the foam board is completely unnoticeable.

Unfortunately, one opening does not have an exterior screen, and of course that is the opening with Great Stuff smeared all over it. I don't expect the black painted foam board to last forever, but I do think that it will last long enough until I can afford to purchase vent covers that can be easily installed over the openings. Eventually I will get something like this for all seven openings: Large Outward Mounted Vent Cover (13" x 21")