Image 1

SubSeal Foundation Water Barrier - Siding Moisture Barrier

Free Shipping
  • Product Description

    SubSeal-40 & SubSeal 60 Adhering Waterproofing Membrane

    MFM SubSeal is a 40 or 60 mil thick, (depending on the model #) prefabricated self-adhering sheet-type waterproofing membrane. It is composed of a tough multi-layer high-strength polymer film that is coated with a layer of specially formulated rubberized asphalt adhesive. A release sheet protects the asphalt and is removed as the membrane is installed. Mastic selvedge on both edges for improved sealing. SubSeal is engineered to be a multi-purpose waterproofing sheet suitable for use under siding, exterior plaster, as a through wall flashing or in sub-grade applications where the membrane is protected from long-term ultraviolet exposure. SubSeal adheres aggressively to most clean, dry substrates including metal, wood vinyl and masonry. SubSeal may be used in foundations and other below grade structures, plaza decks, balcony waterproofing, under siding, exterior plaster and as a through wall flashing. SubSeal complies with ICC-ES AC148 (ICC-ES ESR-2783) and ICC-ES AC38 (ICC-ES ESR-3980).


    Volume pricing available on orders of 25+ Cartons




    SubSeal™ is designed for Extreme Moisture Protection

    SubSeal is engineered to be a multipurpose waterproofing sheet suitable for above and below grade, as well as vertical or horizontal applications. Intended uses include:

    • Foundation walls
    • Through-wall flashings
    • Plaza and balcony decks
    • Parking garages
    • Sills, pot shelves, pony walls and parapets
    • Floor and planter structures
    • Under stucco
    • Sealing SIPS building panels or DensGlass®
    • Around windows and door frames

    SubSeal adheres aggressively to most clean, dry substrates including metal, wood vinyl and masonry. It is self-sealing around fasteners to prevent water penetration. The special waterproofing adhesive has a broad temperature range allowing installation in cold weather.  SubSeal carries a 10-Year Limited Warranty.

    SubSeal™ meets the requirements of ICC-ES AC148 - report ICC-ES ESR-2783, and ICC-ES AC38 - report ICC-ES ESR-3980.


    Concrete Wall Installations:

    Prior to installation on concrete, the surface must be primed with an asphalt based primer. The following are a list of asphalt based primers approved by MFM:

    • APOC 103
    • Bulldog Asphalt Primer
    • Karnak 108
    • Lucas 315

    When installed over a wood or metal surface, a primer is not required.


    Cold Temperature Installation:

    If installing SubSeal in temperatures below 50 degrees, a spray adhesive is recommended for optimal adhesion. The following adhesives are approved by MFM:

    • 3M HI TEK
    • 3M 77

  • Product Reviews


    Write A Review

    1. Seems like an excellent product

      Can be a little tricky to apply - definitely a 2 person job, but very sticky backing creates a great seal. We used our to waterproof the joint between our SIP panels and the pier-and-beam foundation.

      Adheres very well... but be careful applying it.
      on Apr 28th 2020

    2. Even better than expected

      I used this product to seal my basement foundation due to vaious cracks/openings in block. The adhesion was very tacky and easy to apply. The thicknesss was just right, easy to cut with razor knife, yet thick and durable and will not tear. The paper backing peeled cleanly for a simple transition onto the wall. on Oct 24th 2017

    3. Good stuff

      Company responded in timely manner regarding my check on status and updated me as status changed. Product was as advertised and easier to install than I expected. I believe it will provide the barrier I was looking for. on Feb 7th 2017

  • Find Similar Products by Category