Underseal® Blindside™ Membrane

Underseal® Blindside™ Membrane is a tough, 73-mil pre-concrete pour waterproofing membrane/vapor barrier designed to virtually eliminate water and vapor transmission through below grade concrete walls.
Underseal® Blindside™ Membrane is used as a waterproofing membrane where vertical, positive-side waterproofing is required to be installed before the foundation walls are poured. A strong mechanical bond is developed between the membrane and concrete at the time of pouring as the concrete intermingles with the fibers of the nonwoven geotextile. A strong adhesive bond is created when the static load and thermal reactive heat of the concrete slab causes sealant/adhesive compound to have an intimate contact with the concrete surface preventing water migration. With both a mechanical and adhesive bond, the concrete will be tightly sealed and bonded to the membrane, creating superior protection against moisture intrusion. 73-mil Underseal® Blindside™ can also be used in certain horizontal applications. Contact Polyguard for more information.

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Features & Benefits

Lasting Durability: Tough 3-layer composite membrane - Technology that has stood the test of time.

Outstanding Puncture Resistance: 2 times higher than the new AC 527 building code requirement - Better protection against backfill damage.

Strong Mechanical Bond: Our inner fiberous layer embeds itself into the cured concrete creating a very strong mechanical bond - ensures our waterproofing system will stay in place as the building and outside soil move during the building's lifetime.

Resistant to Water Migration: An adhesive bond is created when heat from the concrete wall while curing , causes our compound to melt onto the concrete's positive side surface creating a continuous sealed structure.

Horizontal Installation: Blindside™ Membrane may also be installed horizontally over prepared sub-base such as mudslab, carton forms, fine crushed beds/pea gravel or Polyguard approved drainboard.

Superior Joints: Strong laps seams create a long lasting, water tight system - Outperforms the new AC 527 standard (ASTM 1876) by more than 40%.

Crack Protection: Blindside is thicker than most non asphalt based competitive products which gives it the stress-absorbing and elongation properties to maintain a watertight seal.

Helps Manage Harmful Gases : Acts as a barrier against toxic contaminants methane and radon gas, which may attempt to enter the structure through cracks in the concrete.