Composeal Grey 40 mil Waterproofing Membrane


  • Easily Formed to Fit Any Dimensions or Drain Locations
  • Durable and Long Lasting
  • Ideal for New Construction & Renovations
  • 40 mil Thickness
  • Available in 5 & 6 foot widths
  • 100 foot rolls
  • Meets and surpasses ASTM D4551
  • Made in the USA

Product Documents


For Waterproofing under ‘Thick Bed’ tile installations and protects from costly secondary water damage


COMPOSEAL GREY complies with the standards of ICC-ES for the USA and Canada (report PMG-1459) and and NES (PCR SP 102).  COMPOSEAL GREY has separate municipal approval where required, City of Los Angeles (RR#4398), City of Philadelphia (40 mil), Metropolitan Dade County, Florida and The Commonwealth of Massachusetts.  Approval is no longer required in New York City for concealed PVC waterproof membrane.

COMPOSEAL GREY also complies with the Corps of Engineers specs for PVC shower pan material (para 15 p1-18) and meets the requirements of FHA Publication 4900.1.

COMPOSEAL GREY meets and surpasses the engineering requirements of the American Society for Testing and Materials (ASTM).  ASTM D4551 is the test standard established for PVC membranes used for Shower Pans.

  • Flexible Waterproofing for Floors & Walls
  • Custom Tiled Showers, Baths, Fountains, Roof Decks, Terraces, Exterior Stairs & Walkways
  • Can Be Easily Formed to Fit Any Dimensions or Drain Locations
  • Durable and Long Lasting
  • Ideal for New Construction & Renovations
  • Economically Priced
  • 50% Recycled Content
  • 40 mil Thickness
  • Available in 5 & 6 foot widths
  • 100 foot rolls
  • Meets and surpasses ASTM D4551 for PVC flexible waterproofing membrane
  • Made in the USA

Installation Requirements

Before placing pan, see that the sub-floor is sloped toward drain ¼” per foot using cement mortar if necessary, and is free of loose objects or projections such as nail heads or gravel.

Make turn-up along walls not less than 3” above curb line, allowing sufficient material to fasten to outside face of curb and out onto floor a few inches away from shower if possible.  If there is no curb in the shower,

materials should be fastened 6” above the floor.

Notch wood studs to ½” to the height of the pan to allow COMPOSEAL tobe flush with face of the studs. For metal studs, use furring strips (¼” to ½”) above the top of the pan.

Fasten 3” or higher above the top of curb. Use flathead roofing nails or staples on wood studs.  Use drywall screws and washers on metal studs. DO NOT penetrate the membrane anywhere below the 3” mark in order to maintain waterproof integrity of the pan.

Use bolt-down clamping-ring type drain with weep-holes. Set so sub-drain lip is flush with subfloor. Trim opening for drain exactly to the size of drain opening and NOT out to bolt holes.  Pierce membrane at the bolt holes with a nail or the like to accommodate bolts with a tight fit.  Use Compotite Polyseal or a 100%  mold/mildew resistant silicone to bond the pan and sub-drain.



COMPOSEAL GREY sheets can be welded together to create a perfect waterproof bond with instant contact strength using Weld-Tite by Compotite Flexible Vinyl Cement.  Use only Compotite approved PVC cement for seaming and welding Composeal.  Lay sheets with an overlap of two inches with upper lap edge toward direction of watershed.  Fold back top edge and apply Weld-Tite by Compotite Flexible Vinyl Cement to both surfaces.  Once the surfaces have become slightly tacky place together and press or roll to form a tight bond.  Always verify complete adhesion of the layers.


COMPOSEAL’s multi-purpose, preformed corners/curb protectors are available to reinforce waterproofing at all corners and curbs. Use the Weld-Tite by Compotite Flexible Vinyl Cement. These protectors are sold in pairs and can be used for all outside corners asshown in (Figure 4).  Inside corners are available but Compotite DOES NOT recommend using them for most installations.  When side corners are cut they weaken the installation.When side corners are cut they weaken the installation.pinholes. After drying, set the upper clamping ring onto the AquaShell RS membrane with a continuous bead of polyurethane caulk or similar material. A toilet flange can be treated in the same manner. Can also be used with reinforcing fabric to bond to the flange of the Composeal linear drains.


COMPOSEAL GREY is bonded to the sub-drain assembly using Composeal Polyseal

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