Top Hats

Top Hats are designed to form an effective seal where a pipe, duct or service penetrates a construction membranes. Each unit is manufactured from a material that has the same properties as the membrane type being used, in order to provide continuous VOC, ground gas and/or damp proof protection.


  • Top hats available in a range of different materials
  • Single, double and multiple penetration options are available
  • Supplied complete with a jubilee clip
  • Suitable for welded or taped installations

Each Top Hat unit is supplied to suit the number and diameter of the penetration and can be installed as part of either a welded or taped installation.


Provides an effective seal around pipe, duct and service penetrations within construction membranes.


Please see suitability table below:

Product Puraflex Membrane Puraflex Tank Tri-Gas Membrane Gas Resistant Self Adhesive Membrane Radon Membrane
Puraflex Top Hat
Tri-Gas Top Hat
HDPE Top Hat


Data Sheets

Product Issue Date Version Size Download

MSDS Data Sheets

Product Issue Date Version Size Download


Product Issue Date Version Size Download
Construction Solutions 01/2020 2 6.6 MB
VOC & Ground Gas Protection 07/2019 4 4.0 MB

NBS Clauses

Our NBS Clauses are hosted on the external website - view NBS Clauses

BIM Library

Please select the BIM file in the format you require.

Name IFC Size IFC Download Revit Size Revit Download
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For international enquiries please contact Peter Blanchard

For enquiries in the Manchester or Liverpool
areas please contact James Provan

Or contact Cordek Head Office