Lay the cut vapor barrier flat on the crawl space floor, ensuring it covers the entire area. Use a staple gun or adhesive to secure the barrier to the walls, piers, and any other vertical surfaces. Ensure a tight seal by overlapping the seams and using adhesive or tape to secure them.
Don't: Staple or Nail Vapor Barriers without Using Proper Tapes. Vapor barriers are not meant to be punctured. Once the vapor barrier has been punctured, it jeopardizes the integrity of the liner. Many vapor barriers are difficult to puncture and will uphold their resistance through heavy installation and use.
Attaching with Staples
One common method for installing a vapour barrier is by stapling it to the substructure. Begin by unrolling the construction membrane and stapling it in place. However, keep in mind that staples create small perforations in the film, which can compromise the airtight seal.
It's also important to ensure that the barrier is completely sealed so that no moisture can get through it. Using staples or tape along all edges and seams will help create a strong seal.
Either fasten furring strips to the walls and fasten the vapor barrier to that, or just use the furring strips as battens over the vapor barrier to hold it in place. Can help to wrap the end of the plastic around the batten before attaching it to the wall.
Lay the cut vapor barrier flat on the crawl space floor, ensuring it covers the entire area. Use a staple gun or adhesive to secure the barrier to the walls, piers, and any other vertical surfaces. Ensure a tight seal by overlapping the seams and using adhesive or tape to secure them.
When installing on a poured concrete foundation, use DimpleGrip Molding for the top and side edges and Super Plugs to fasten the body of the membrane to the wall. Use Membrane cap molding for angles or sloping areas. Fasten with 1 ¼” or 1½“ concrete nails. Use standard tar based caulking for seams or overlaps.
The right tape is crucial for crawl space vapor barrier installation. Encapsulating a crawl space requires 2-sided butyl tape and vapor tape for seaming panels.
The worst problem with flooding in a crawl space is when the standing water is on top of the vapor barrier. The vapor barrier prevents the water from draining, which essentially traps the water in the crawl space, constantly releasing moisture into the air.
On most projects where insulation meets the under-slab vapor barrier, we have found that the project teams elect to install their insulation first and to lay the vapor barrier over top. Various industry leaders have commented on the advantage of placing the vapor barrier directly beneath the slab.
Extend vapor retarder at least 6 inches up walls, columns, and footings. Use physical attachments where practical and necessary for long-term adhesion of vapor barrier to vertical surfaces. Overlap all seams at least 12 inches using a reverse or upslope lapping technique.
CROWN STAPLES 1/2" & 7/16”
Crown staples are made for secure fastening of plastic sheeting, vapor barrier wrap, furniture upholstery, fabric on wood frame applications and more.
The final step in installing a vapor barrier is to seal the seams with tape. This will create a complete moisture barrier and keep out drafts. Vapor seal tape comes in a roll with marked edges which makes for fast application.
No, DuPont Tyvek is not a vapor barrier. It is breathable, allowing moisture vapor to pass through it.
We don't recommend you seal your vapor barrier down to the concrete, as that can damage your subfloor.
However, if not installed correctly or if damaged, vapor barriers can actually contribute to mold growth.
Roll Out and Cut Plastic Sheets
Begin at one side of the crawl space and lay down 6-mil or thicker polyethylene plastic over the entire crawl space. Cut the sheets to size, allowing 6 inches or more along walls. Overlap the seams by no less than 12 inches and secure them together with the poly PVC tape.
The combination of a vapor barrier and gravel covering your crawl space sounds like a good idea. But it's very important in which order you install them. You need to put the gravel down first and then put the vapor barrier on top to keep your crawl space dry and free from crawl space mold.
Best Practices for Storing and Installing Vapor Tape
In order to ensure that the tape sticks well, remove any contaminates or dust prior to adhering the tape to a surface. Lastly, keep in mind the colder the environment is, the longer it will take for the bond to set.
Acoustical Sealant
It remains flexible even after curing, which makes it an ideal choice for sealing vapor barriers.
DO NOT USE DUCT TAPE for vapor barrier. If you are taping vapor barrier plastic get a construction tape like TUCK tape or some pressure sensitive tape for vapor barrier.
You can also use a Christmas tree fastener for vapor barrier, or you can even get a ram set fastener if you want to mechanically attach. If you're against mechanically attaching foam board and vapor barrier to the wall because you're concerned about putting holes in your foundation wall, you could try an adhesive.
Insulating foam sealant can be used to fill any cracks between the frame of the house and the door. Apply a new layer of caulking to the area where the window meets your siding to prevent any other leaks. A fresh coat of paint on the window frames and doors can prevent moisture from reaching the wood.