Visqueen Ultimate Geoseal is a 1mm thick, robust pre-applied waterproofing barrier. It is coloured grey on the upper surface and black on the reverse. The grey surface is textured to aid adhesion to cast concrete. The barrier is supplied in single wound rolls (not folded), 2.44m x 41m.

Radon, carbon dioxide, methane, and VOC protection – NHBC NF94 guidance:

Visqueen Ultimate GeoSeal when installed with welded joints complies with NHBC Foundation’s NF94 publication, Hazardous ground gas - an essential guide for housebuilders, in Type B membrane locations in reinforced cast in situ concrete floor slabs (ground bearing, suspended or raft). Visqueen Ultimate GeoSeal also complies with this guidance when installed with welded joints in Type C membrane locations in precast suspended segmental subfloors and reinforced cast in situ concrete floor slabs (ground bearing, suspended or raft). For site or zone characteristic gas situations of CS4 and above, contact Rawlins Technical on 0113 2455450 (option 2) or send a message to [email protected].

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• Approvals and Standards
• System Components
• Storage and Handling
• Preparation
• Installation
• Usable Temperature Range
• Additional Information

Approvals and Standards

• Third party accreditation (BDA BAF-18-056-P-A-UK)
• Complies with NHBC Foundation’s NF94 guidance for use in Type B and Type C membrane locations
• Suitable for use as a Type A Barrier Membrane (Tanking Membrane) to BS 8102:2022
• Complies with CIRIA C748:2014
• Complies with the methane gas transmission rate, mass per unit area and thickness requirements of BS 8485:2015 + A1:2019
• Suitable for all Characteristic Gas Situation (CS) ground gas regimes
• Conforms to the specification requirements of BR 211:2023
• CE Mark EN 13967:2012
• Quality Management System ISO 9001:2015
• Occupational Health and Safety System ISO 45001:2018
• Environmental Management System ISO 14001:2015

System Components

• Visqueen Ultimate Double Sided Jointing Tape, 100mm x 15m
• Visqueen GR Lap Tape, 150mm x 10m
• Visqueen Ultimate Retaining Discs, 50mm long x 35mm head diameter x 500 per box
• Visqueen Ultimate Top Hat Units
• Visqueen Preformed Units - contact technical for more information on 0113 2455450 (option 2) or send a message to [email protected]
• VisqueenPro Detailing Strip, 300mm x 10m, 500mm x 10m
• Visqueen Pile Cap Sealer, 25kg
• Visqueen IGW5 and IGW10 Waterstops

Storage and Handling

Visqueen Ultimate GeoSeal should be stored horizontally, under cover in its original packaging. Care should be taken when handling the product in line with current manual handling regulations.

Preparation

Visqueen Ultimate GeoSeal should be installed on a smooth continuous surface e.g. compacted blinding layer, smooth concrete blinding or well consolidated MOT Type 1. The substrate should be free from irregularities such as voids or protrusions.

Where protection against hydrostatic water pressure is required, the barrier should be applied with welded joints.

The barrier can be cut with a sharp retractable safety knife or robust scissors.

Installation

Visqueen Ultimate GeoSeal should be loose laid on horizontal substrates and pre-applied to vertical substrate with the grey textured side facing towards the wet cast concrete so that a key to the concrete can be achieved.

The barrier has been designed to exhibit superior welding properties using hot wedge, hot air or extrusion welding, therefore onsite welding of all lap joints is recommended for all applications, and should be employed when hydrostatic water pressure or hydrocarbon/VOC contamination is present.

Alternatively, when the barrier is used for damp proofing, ground gas protection and sites where hydrostatic water pressure or hydrocarbon/VOC contamination is of low risk, lap joints can be bonded with Visqueen Ultimate Double Sided Jointing Tape and sealed with Visqueen GR Lap Tape. When using tapes to secure laps, the overlap should be minimum 150mm and the membrane surfaces to be jointed should be dry and free from contamination such as dust or sand. Once the tapes are applied, the lap should be well rolled with a seam roller to ensure full adhesion and continuity.

The barrier should not be taken through any masonry wall. The relevant Visqueen damp proof or gas proof course should be taken through and extended beyond the wall by a minimum of 250mm where it can be jointed to the barrier with the above tapes.

When installed vertically, the barrier should be pre-applied to temporary formwork or the adjoining structure. Visqueen Retaining Discs are available to provide a means for securing the leading edge of the membrane to the temporary formwork. The barrier should be installed with the smooth black surface facing the formwork. Visqueen Retaining Discs should be mechanically fixed at maximum 400mm centres to the internal face of the shuttering using oval nails. A suitable power tool and 6mm drill bit to create a pilot hole in the barrier, it should be secured over the protruding section of the retaining disc. The top edge of the barrier should be trimmed to approximately 10mm below the top edge of the slab. Once the concrete has set, the oval nails should be removed by pulling through from the external face of the shuttering. When the temporary formwork is removed the Visqueen Retaining Discs should be visible on the external (smooth black) face of the barrier. Continuity of the barrier system with the damp or gas proof course is maintained using Visqueen Gas Resistant Self Adhesive Membrane.

Visqueen Ultimate Preformed Top Hat Units should be used for sealing service entry pipes. The base of the top hat and the upstand should be bonded using Visqueen Ultimate Double Sided Jointing Tape and sealed with Visqueen GR Lap Tape. The upstand should be secured with the supplied jubilee clip. Alternatively VisqueenPro Detailing Strip can be used to seal service entry points. The upstand should be secured with a jubilee clip.

Forming an effective barrier to gases may give rise to complex three-dimensional detailing where, it is recommended that welded membrane or Visqueen Ultimate Preformed Units are used e.g. corners. Alternatively VisqueenPro Detailing Strip can be used to seal awkward junctions.

If the barrier is punctured or perforated a patch of the same material should be lapped at least 150mm beyond the limits of the puncture and, depending on the specified jointing method, either welded in position or bonded with Visqueen Ultimate Double Sided Jointing Tape and sealed with Visqueen GR Lap Tape. Alternatively a patch can be formed using VisqueenPro Detailing Strip and lapped at least 150mm beyond the perimeter of the puncture.

Due to the robust nature of the product, the barrier can withstand normal on-site foot traffic and the activities associated with the laying of a reinforced concrete slab without the need for additional protection. However, care should still be taken to ensure that the barrier is not punctured, stretched or displaced when applying the reinforced concrete.

In high temperature conditions the barrier should be covered immediately after installation.

Usable Temperature Range

It is recommended that Visqueen Ultimate GeoSeal and all associated system components should not be installed below 5°C.

Additional Information

Where required, Visqueen’s network of preferred installers can install the barrier and offer the client a fully warranted system. To assist build sequencing, Visqueen Ultimate Gas DPC is available for gas protection through the wall construction.

When used in accordance with CIRIA C748:2014 or BS8485:2015 + A1:2019, a subfloor ventilation system or pressure relief maybe required.

For additional detailing information contact Rawlins Technical on 0113 2455450 (option 2) or send a message to [email protected]