Moisture Barrier Systems “Clean Crawlspace Systems”

Groundwater is a significant source of ambient moisture in many homes. This vapor can travel throughout a home’s envelope creating condensation in the crawlspace, living space, and attic. Moisture barriers, otherwise known as vapor retarders/ barriers are installed over the earth’s surface in crawlspace areas and below slab foundations. The purpose of this installation is to reduce or prevent ground moisture from getting into the air and impacting the structure.

The most simple and inexpensive barrier is 6 mill plastic laid over the earth. This is a requirement in new and remodels construction in most building jurisdictions.  Where it is not required, good building practices should incorporate a barrier for all earth floor crawlspaces. Often the plastic is simply laid out to cover the earth with no attachment to foundation walls. This can be somewhat effective, though you run the risk of the barrier moving and being pulled away from areas of the ground.

Sealed Moisture Barrier in Lake TahoeA sealed moisture barrier provides a much more effective and durable solution. This is more frequently becoming a requirement for new home construction where ventilation is limited due to fire restrictions. A sealed barrier is preferred if the crawlspace floor has a steep slope, if there are known groundwater issues, or if the barrier is being installed in a high traffic area. All our sealed barriers use a laminated liner material that is less susceptible to tears and punctures than plastic. It is advisable to use a quality barrier product due to the associated labor costs. Plastic becomes brittle with age and can easily be punctured or torn.

Below are the four levels of barriers we offer to accommodate your needs and budget.

Bronze Option

  • The soil is cleaned of any debris or sharp items that could damage the barrier. This does not include large boulders or other items that can’t easily be moved.
  • 6 mill plastic is installed to cover the earth’s surface. Some adhesive and tape will be used to secure the barrier in place.
  • This is not suitable for crawlspaces with significant elevation change or groundwater issues.
  • This barrier does not comply with building jurisdictions as a sealed crawlspace moisture barrier.

Prices typically range from $500-$2,000 depending on size, clearance/access, and amount of debris to be removed

Silver Option

  • The soil is cleaned of any debris or sharp items that could damage the barrier. This does not include large boulders or other items that can’t easily be moved.
  • Barriers are sealed to themselves with a combination of sealer and seam tape. They are then attached and sealed to perimeter walls and interior foundations with a butyl caulking that provides a seal and attachment to perimeter walls.
  • We use a 12 mill reinforced and laminated moisture barrier that is approved to be part of a radon mitigation system. The barrier will run to cover the earth’s surface and up the foundation walls a minimum of 1’ from the ground.
  • The barrier will be sealed to Interior foundations with butyl caulking and be wrapped with seam tape to seal to the footing.
  • Stop and Drain water shut-off systems will have a PVC chase installed to allow handle action.
  • Any drains set above the barrier will be brought below the barrier by use of a rubber hose and clamp.
  • All drain lines and plumbing that penetrate the barrier will be sealed.
  • In new construction, it is advisable to install the closed-cell foam on perimeter walls after barrier installation to secure the barrier and provide additional protection from condensation. 
  • This is best in crawlspaces that are level and without big grade changes.

Prices typically range from $2,000-$5,000 depending on size, clearance/access, and amount of debris to be removed

Gold Option

  • The soil is cleaned of any debris or sharp items that could damage the barrier. This does not include large boulders or other items that can’t easily be moved.
  • A felt liner is installed to run over the ground and under the barrier. This helps to protect the barrier from sharp items that can’t be removed. Felt liners may also provide small amounts of insulation value. The liner covers the entire earth’s surface and ends at the perimeter foundation wall. The liner will overlap itself at the seams and be glued in spots to ensure it remains in place.
  • Barriers are sealed to themselves with a combination of sealer and seam tape. They are then attached and sealed to perimeter walls and interior foundations with a butyl caulking that provides a seal and attachment to perimeter walls.
  • We use a 12 mill reinforced and laminated moisture barrier that is approved to be part of a radon mitigation system. The barrier will run to cover the earth’s surface and up the foundation walls a minimum of 1’ from the ground.
  • The barrier is sealed to Interior foundations with butyl caulking and be wrapped with seam tape to seal to the footing.
  • Stop and Drain water shut-off systems will have a PVC chase installed to allow handle action.
  • Any drains set above the barrier will be brought below the barrier by use of a rubber hose and clamp.
  • All drain lines and plumbing that penetrate the barrier will be sealed.
  • In new construction, it is advisable to install the closed-cell foam on perimeter walls after barrier installation to secure the barrier and provide additional protection from condensation. 
  • This is best in crawlspaces that are level and without big grade changes.

Prices typically range from $2,600-$8,500 depending on size, clearance/access, and amount of debris to be removed

Platinum Option

  • The soil is cleaned of any debris or sharp items that could damage the barrier. This does not include large boulders or other items that can’t easily be moved.
  • A felt liner is installed to run over the ground and under the barrier. This helps to protect the barrier from sharp items that can’t be removed. Felt liners may also provide small amounts of insulation value. The liner covers the entire earth’s surface and ends at the perimeter foundation wall. The liner will overlap itself at the seams and be glued in spots to ensure it remains in place.
  • Barriers are sealed to themselves with a combination of sealer and seam tape. They are then attached and sealed to perimeter walls and interior foundations with a butyl caulking that provides a seal and attachment to perimeter walls.
  • We use a 12 mill reinforced and laminated moisture barrier that is approved to be part of a radon mitigation system. The barrier will run to cover the earth’s surface and up the foundation walls a minimum of 1’ from the ground.
  • The barrier is sealed to Interior foundations with butyl caulking and be wrapped with seam tape to seal to the footing. Larger footings will also have a termination strip and anchors.
  • Stop and Drain water shut-off systems will have a PVC chase installed to allow handle action.
  • Any drains set above the barrier will be brought below the barrier by use of a rubber hose and clamp.
  • All drain lines and plumbing that penetrate the barrier will be sealed.
  • All high traffic areas will have outdoor carpet run above the barrier.

Prices typically range from $3,400-$10,000+ depending on size, clearance/access, and amount of debris to be removed

Sub-Barrier Insulation

For conditioned crawlspaces that have no ventilation with the outside, insulation is typically run under the barrier to provide a thermal envelope. This ranges from R-1.5 to R-3 and consists of honeycomb air cells that are constructed of plastic. The rolls of insulation are installed to cover the earth and are sealed to themselves with seam tape.

Contact us for pricing.