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Volclay Swelltite

Volclay Swelltite is a bentonite waterproofing membrane designed for below grade masonry block, split-slab deck and plaza construction. Swelltite combines the natural waterproofing abilities of Volclay sodium bentonite with a high-strength geo-membrane liner for tensile strength and puncture resistance. Swelltite's active bentonite compound can expand to seal small installation imperfections or punctures in the membrane.

Key Features
  • Swelltite is easy to install
  • Ready for use and requires no set-up
  • Does not require torching or priming
  • Overlapped seams and mechanical fasteners eliminate installation variables in the field
  • It can be applied in all weather conditions to green concrete 
  • Swelltite is conveniently packaged in easy to handle 1 metre wide rolls
  • The tough geomembrane liner eliminates the need for protection board in some installations
  • Applications include split-slab deck and plaza construction, backfilled concrete foundation walls, masonry block foundation walls, and tunnels
  • Swelltite contains virtually zero VOC
  • Proven effective for split-slab, plaza deck, protected membrane roof and landscaped assemblies
  • Can be installed in temperatures below freezing
Scope of Use

Swelltite is designed for waterproofing below-grade vertical and horizontal structural surfaces, as well as, above grade split-slab construction used with plaza areas, parking garages and sports stadiums.

Swelltite is excellent for:

  • Below-grade masonry block walls
  • Split-slab Plaza Deck Construction
  • Cut & Cover Tunnels
  • Masonry Block Foundation Walls
  • Concrete Foundation Walls
  • Earth-covered Structures


  • Ready for use and requires no set-up
  • Does not require torching or priming
  • It can be applied in all weather conditions to green concrete 
  • Can be installed in temperatures below freezing
Limitations on Use
  • Swelltite should only be installed after proper substrate preparation has been completed and is suitable to receive the waterproofing system.
  • Concrete work should use conventional cast-in-place forms that produce a smooth surface.
  • Do not use stay-in-place concrete forming; use removable forming products only.
  • Do not use product without proper backfill or topping slab confinement.
  • Swelltite is not designed for unconfined above-grade waterproofing applications or subsurface applications that do not provide full confinement coverage.
  • Do not install Swelltite on horizontal plaza deck applications that utilize pavers placed on pedestals. Swelltite is not designed to waterproof expansion joints.
  • Expansion joints require a properly engineered expansion joint sealant product manufactured by other companies (please see: Emseal).
  • Do not install Swelltite in standing water or during precipitation.
  • If ground water contains strong acids, alkalis or is of a conductivity of 2,500 µmhos or greater, submit water samples to the manufacturer for compatibility testing.
  • Consult Allco for special installation guidelines that apply to shotcrete and precast concrete construction.
  • Install Swelltite only in dry weather. Installation should not proceed when work areas are flooded or excessively wet, nor when rain can be reasonably anticipated before Swelltite can be properly covered.
Statement of Building Code Compliance

In the opinion of BRANZ, the Volclay Waterproofing System if designed, used, installed and maintained in accordance with the statements and conditions of this Appraisal, will meet the following provisions of the NZBC:

  • Clause B2 DURABILITY: Performance B2.3.1 [a] not less than 50 years. the Volclay Waterproofing System meet this requirement. See Paragraph 14.1.
  • Clause E2 EXTERNAL MOISTURE: Performance E2.33. the Volclay Waterproofing System meet this requirement. See Paragraphs 16.1 - 16.3.
  • Clause F2 HAZARDOUS BUILDING MATERIALS: Performance F2.3.1. the Volclay Waterproofing System meet this requirement and will not present a health hazard to people.

BRANZ Appraisal is of an Alternative Solution in terms of New Zealand Building Code compliance.

In-Service History

Introduced in 1987, Volclay Swelltite was the first bentonite waterproofing membrane designed for masonry block work, split-slab deck and plaza construction. Over 20 million square metres of Swelltite have been installed worldwide on projects such as airports, commercial offices, parking structures, and transportation tunnels. Volcay Swelltide has 20 years of proven waterproofing success.

Other Performance Attributes
  • Swelltite contains virtually zero VOC
B2 Durability compliant
E2 External Moisture compliant
External Moisture
F2 Hazardous Building Materials compliant
Hazardous Building Materials
BRANZ Appraised
BRANZ Appraised
Product Manual
BRANZ Appraisal 507

507 [2019] (amended 2022)

Volclay Brochure

Allco Waterproofing Solutions specialise in quality waterproofing products supplying Volclay, Casali, Hydrotech and JM TPO.

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