|Why Specify UNDERSEAL™ Underslab Waterproofing Geomembrane
Over a Heavy Duty Vapor Barrier?
|If you already specify a thicker vapor barrier, you have taken a big step towards improved underslab moisture protection. Also importantly, you have recognized that much of what is called the Indoor Air Quality Problem can originate underneath the slab and outside of the foundation walls.Now there is a new level of underslab protection, far beyond a vapor barrier, and available for environmentally sensitive projects. UNDERSEAL™ Underslab Waterproofing Geomembrane is a three layer composite, made by combining a geomembrane, a sealant, and a geotextile fabric.
Before viewing this page, we recommend that you see the “Why Most Vapor Barriers Fail” presentation.
|Layer 3 —||
High strength nonwoven geotextile
|Layer 2 —||
Thick elastomeric sealant barrier layer
|Layer 1 —||
20 mil Geomembrane
|Layer 1 – The Geomembrane:UNDERSEAL™ Underslab Waterproofing Geomembrane STARTS with a geomembrane – a 20 mil thickness one, thicker than any vapor barrier on the market.
Layer 2 – The double thickness elastomeric sealant layer:
On top of the geomembrane is a double thickness of sealant.
The sealant converts geomembrane into a full blown waterproofing system, with properties exceeding that of Polyguard’s 650 waterproofing membrane, used for commercial building worldwide since 1970.
ICC-ES Legacy Report #2136
|3.||Radioactive Radon Gas|
|Also, the sealant is a permanent seal, proven in use by 34 years of research and use. Polyguard underseal membranes have been used by state Departments of Transportation to reduce cracking and to provide a permanent seal which is resistant to joint movement and pavement failure:
One more advantage of this elastomeric sealant layer; it is self-healing. This means that, if small punctures occur in the underseal, the barrier sealant will flow back together.
Layer 3 – High Strength Geotextile Fabric:
The top fabric layer performs several functions:
Compared to a simple vapor barrier, Polyguard’s UNDERSEAL™ Underslab Waterproofing Geomembrane protected geomembrane has the following advantages:
1. The thickness of the geomembrane exceeds even the best vapor barriers.
Compare to Grace Products
Pre-applied Waterproofing Membranes
Preprufe® Waterproofing System (Preprufe® 300R & 160R)
Preprufe® 300R & 160R membranes are unique composite sheets comprising a thick HDPE film, an aggressive pressure-sensitive adhesive and a weather resistant protective coating.
Unlike conventional non-adhering membranes, which are vulnerable to water ingress tracking between the unbonded membrane and structure, the unique Preprufe seal to concrete prevents any ingress or migration of water around the structure.
The Preprufe R System includes:
Preprufe 300R – heavy-duty grade for use below slabs and on rafts (i.e. mud slabs). Designed to accept the placing of heavy reinforcement using conventional concrete spacers.
Preprufe 160R – thinner grade for lighter applications and reverse tanking (i.e. blindside zero property line) applications against permanent formwork such as soil retention systems.
Preprufe Tape LT – for covering cut edges, roll ends, penetrations and detailing (temperatures between -4°C (25°F) and +30°C (86°F)).
Preprufe Tape HC – as above for use in Hot Climates (minimum 10°C (50°F)).