Best Crawl Space Seam Tape

The best seam tape used when encapsulating a crawl space is not found at the local box stores.

Many contractors, like Crawl Space Ninja, use specially designed waterproof tapes for vapor barrier installation.

These tapes are strong and waterproof to keep the plastic joined together regardless of the environmental conditions of the crawl space. In this article I list many of the characteristics we look for in a great tape. These features are found in the tapes we install on every job.

What is Crawl Space Seam Tape

Crawl space seam tape is a vinyl tape used specifically to adhere the cut plastic to itself when performing crawl space encapsulation. Plastic in most crawl space repair projects must be cut into sections to install properly.

The crawl space has many obstacles and cutting the plastic makes it easier to install around pillars, pipes, and walls. Seam tape sticks best to the vapor barrier.

Using tape only to adhere the plastic to foundation walls is not recommended and can fail over time.

Seam tapes should be sticky but not too sticky.

Best Seam Tapes are Very Sticky

The Exclusive Crawl Space Ninja Seam Tapes and Butyl Tapes are designed to provide high quality in a damp environment.

The width and adhesiveness was a factor used in choosing our seam tape. The tape must be durable and able to prevent the plastic from separating no matter what conditions the crawl space is experiencing.

A 4-inch wide sticky seam tape is best used when fully encapsulating and waterproofing the crawl space.

Vapor Barrier Tape That is Too Sticky is a Problem

It is hard to believe that a tape can be too sticky.

The Crawl Space Ninja Seam Tape is the perfect balance of adhesion but not so sticky it will not come off the roll. I have tried other tapes that actually left the adhesive on the back of the tape. This took away from its ability to seal the vapor barrier properly. It was also a huge time waster because of the adhesive preventing the removal of the tape.

Don’t fight with tapes that are too sticky, check out our seam tape at

Encapsulation seam tape image

Seam Tape Product Description

  • 9-mil Seam Tape 4″ x 180′
  • Polyethylene film
  • Pressure sensitive adhesive
  • White Shiny Finish


  • Agricultural
  • Wire identification
  • High durability surface protection
  • Polyethylene splicing
  • General industrial masking, bundling, splicing and repair applications
  • All-purpose waterproof sealing applications

Product Benefits

  • Provides a watertight seal and humidity resistance in a range of weather conditions
  • Low-residue aggressive adhesive allowing the material to be repositioned
  • Bonds well to most surfaces over a wide temperature range
  • Good conformability for application to rough or irregular surfaces

Q: How Much Crawl Space Seam Tape Do I Need?

Typically, we recommend 1 roll (4″x180′) for every 250 square feet of crawl space. Additionally, if you have support pillars, add 1 additional roll for every four pillars.

Contact Crawl Space Ninja for Your Crawl Space Encapsulation

Do you need help with mold removal, crawl space encapsulation, crawl space insulation, vapor barrier, waterproofing, or controlling humidity in your crawl space and you live in Georgia, Delaware, North Carolina, South Carolina, Tennessee or Kentucky? If so, please contact us to schedule your assessment.


Contact us if you need help fixing your crawl space or yard drainage by clicking here.


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