Concrete slabs and foundation walls almost inevitably crack,
providing entry to water, contaminates, and insects.
Underseal™ not only seals out these harmful substances, but has been proven through over 30 years of use in highway pavements, to maintain the seal, even if the pavement above it cracks.

Click Here to view the UNDERSEAL™ Overview highlighting product Features & Benefits

UNDERSEAL™ Underslab Waterproofing Membrane
(previously XT 850)
Patent Applied For

Installed prior to slab pour, UNDERSEAL™ Underslab Waterproofing Membrane contains 3 layers of protection.

1. The bottom layer is a 20 mil geomembrane, highly puncture resistant and stretchable.
2. The middle layer is a 65 mil polymerized asphalt sealant, which acts as a seal and an elastomeric stress absorbing formulation. This is the primary material which guarantees a permanent seal when the concrete cracks or the joint moves above the membrane.
3. The top layer is a high strength geotextile which forms a physical bond to the concrete slab poured on top of it.

UNDERSEAL™ Blindside Waterproofing Membrane is a three layer system, usually installed against vertical drainage boards which are fastened to lagging. Flow 15P & Low Flow drainage boards.

1. A very high strength and puncture resistant, but conformable, polyethylene film layer is installed against the drainage board.
2. A thick layer of elastomeric, stress absorbing polymerized sealant is adhered to the high strength polyethylene.
3. A high strength geotextile is the last layer. This geotextile forms a physical bond to the concrete foundation wall poured against it.

Installed between two slabs, UNDERSEAL™ Split Slab Waterproofing Membrane adheres directly to the base slab.

1. The bottom layer is a 55 mil polymerized asphalt sealant, which acts as a seal and an elastomeric stress absorbing formulation. This is the primary material which guarantees a permanent seal when the concrete cracks or the joint moves above the membrane.
2. The top layer is a 20 mil geomembrane, highly puncture resistant and stretchable.

UNDERSEAL™ Split Slab Waterproofing Membrane does not require a protection board if light construction traffic is present. Many times it is used in conjunction with Polyguard horizontal drainage boards. Flow 18H & Flow 10HV drainage boards.

Installed on vertical foundation walls, Underseal™ Protected Wall Waterproofing Membrane is a self adhesive material, similar to Polyguard's widely specified 650 product, except that it contains a 20 mil geomembrane backing which provides a built-in protection board.

Flow 15P Vertical Drainage Board

Low Flow Protection / Drainage Mat

Flow 18H Horizontal Drainage Board

Flow 10 HV Horizontal Drainage Board

How UNDERSEAL™ acts as a barrier to:

• Moisture
• Toxic Mold
• Radioactive Radon Gas
• Methane
• Pesticides
• Termites

Polyguard has been ISO 9000 certified since 1996. Current certifications are:
- American Natl. Standards Institute
- Dutch Council for Certification
- Deutscher Akkreditierungs Rat