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SubSeal 40 self-adhering water barrier
SubSeal self-adhering barrier application
SubSeal water barrier detail
SubSeal 40 self-adhering water barrier
SubSeal self-adhering barrier application
SubSeal water barrier detail

SubSeal Self-Adhering Water Barrier

$17.82 - $291.59
$17.82
$17.82 - $291.59
$17.82
Free Shipping

Choose Material Thickness and Size: SubSeal-40™ Piece - 3 inch x 3 inch
Self-Adhering Waterproofing Membrane

MFM SubSeal is a self-adhering, sheet-type waterproofing membrane available in 40 mil and 60 mil thicknesses, engineered for extreme moisture protection above or below grade.

Both SubSeal 40 and SubSeal 60 are built from a tough, multi-layer high-strength polymer film coated with a specially formulated rubberized asphalt adhesive, with mastic selvedge on both edges for a tight, dependable seal. The peel-and-stick membrane adheres aggressively to clean, dry metal, wood, vinyl, and masonry, making it a versatile choice for foundation walls, through-wall flashing, plaza and balcony decks, under siding, and a wide range of vertical and horizontal applications.

The 40 mil is ideal for most residential and light commercial waterproofing, while the heavier 60 mil offers added durability for demanding below-grade and high-traffic applications. Both comply with ICC-ES AC148 and AC38, and are easy to cut and apply on the job site.

SubSeal 40 Waterproofing Membrane – Foundation & Siding

SubSeal Self-Adhering Waterproofing Membrane

A prefabricated, self-adhering sheet-type waterproofing membrane engineered for extreme moisture protection — above or below grade, vertical or horizontal.

🧱 Self-Adhering 💧 Extreme Moisture Protection 🚚 Free Shipping
40 / 60 mil
depending on model #
Waterproofing Membrane
SubSeal 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).  ·  Shipping: UPS / Freight (depending on order size)
Documentation & Resources
📄Installation Guide / Technical Information 📄Technical Data Sheet — SubSeal 40 📄Technical Data Sheet — SubSeal 60 📄Approved Primer Guide
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

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

(download the approved primer guide above for additional options)

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

Cold Temperature Installations

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

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