One-part elastomeric polyurethane sealant

Product Description

A high performance elastomeric joint sealant based on proven polyurethane elastomer technology. Silcor LM PU Sealant is a neutral cure system that reacts on exposure to atmospheric moisture. When cured, it forms a durable waterproof seal, which makes it suitable for most applications.


Silcor LM PU Sealant Sealant has excellent adhesion to most surfaces including concrete, brickwork, natural and artificial stone, steel, aluminium, wood, ceramic tiles, rigid plastics and fibre cement sheet.

  • Good UV resistance, long life
  • Single-pack — no mixing
  • Low modulus for high movement
  • Total adhesion — no water tracking
  • Hard wearing, permanently flexible
  • Can be painted after full curing has occurred


Silcor LM PU Sealant is a multi-purpose adhesive sealant with a wide cross section of use in construction and industrial application.

It is ideal for sealing joints in concrete panels, tiles, fibrous cement products, external cladding panels, block work and brickwork.

Silcor LM PU Sealant is used for gap and crack filling, angle fillets, bedding hobs and sealing outlets before application of primers from GCP Applied Technologies and the full waterproof membrane system.

It is also used as:

  • Gap filler between window or door frames
  • Adhesive for shower hobs before waterproofing
  • Adhesive for ceramic tiles subject to impact

It is suitable for use with most of the waterproofing membrane systems from GCP Applied Technologies. Refer to Compatibility for details.

Silcor LM PU Sealant has excellent adhesion to most surfaces including concrete, brickwork, natural and artificial stone, steel, aluminium, wood, ceramic tiles, rigid plastics and fibre cement sheet.


Silcor LM PU Sealant is compatible with most membranes from GCP Applied Technologies as angle fillets, bond breaker, or gap filler before primer and membrane application or to seal flashings and frames installed subsequently including: Silcor membranes, as well as BITUTHENE® membranes.


One 600mL sausage will supply 12 lin. metres of 10mm x 5mm sealant bead. Usage is dependent on joint dimensions.

The correct geometry is:

  • Joint : width ratio of 1:1 up to 12mm wide
  • Depth constant at 12mm up to 24mm and
  • Joint : ratio of 2:1 from 25mm wide


Silcor LM PU Sealant is supplied in 600mL foil sausages, with 20 sausages per carton.

Typical Properties

Property Typical Value
Colour Grey
Tack Free Time 6-12 hrs
Cure Time 24 hr, 2mm
Shore A Hardness 40 +/- 10
Specific Gravity 1.4g / mL
Application Temp 5°C to 30°C
Elongation >700%
Tensile Strength >1.5MPa
Chemical Resistance Excellent

For special applications and service needs not covered in Silcor LM PU Sealant product data sheet, contact your local GCP representative


Surfaces must be sound, smooth and free from dust, laitance, loose matter, oil or other contaminants.

Good adhesion can be achieved on clean, dry, uncontaminated concrete, brickwork, timber, metals, ceramics and most coating surfaces without use of primers. However, adhesion to some surfaces may be improved by use of a primer. For any specific application needs contact your local GCP representative.


Apply Silcor LM PU Sealant using a manually or electrically operated closed-barrel caulking gun. Insert bag into gun, cut top of the bag, replace end cap and use. Extrude sealant firmly into joint to ensure complete contact on joint faces. Smooth as required with a spatula and diluted detergent to give a flat or concave surface.

Shelf Life

Sausages have a shelf life of 9 months from date of manufacture, when stored in a dry, cool place at 25ºC, 60% RH.

Clean Up

Remove uncured Silcor LM PU Sealant with xylene.

Health and Safety

In case of spills and accidents, refer to the Material Safety Data Sheet (MSDS) of the products or when in doubt contact your local GCP representative.

Always wear protective clothing, gloves and protective goggles when handling chemical products.

For full information, consult the relevant MSDS. | For technical information:

We hope the information here will be helpful. It is based on data and knowledge considered to be true and accurate, and is offered for consideration, investigation and verification by the user, but we do not warrant the results to be obtained. Please read all statements, recommendations, and suggestions in conjunction with our conditions of sale, which apply to all goods supplied by us. No statement, recommendation, or suggestion is intended for any use that would infringe any patent, copyright, or other third party right.

Silcor and Bituthene are trademarks, which may be registered in the United States and/or other countries, of GCP Applied Technologies, Inc. This trademark list has been compiled using available published information as of the publication date and may not accurately reflect current trademark ownership or status.

© Copyright 2017 GCP Applied Technologies, Inc. All rights reserved.

GCP Applied Technologies Inc., 2325 Lakeview Parkway, Alpharetta, GA 30009, USA
GCP Vietnam Company Ltd, Lot B14, Section B, Street No. 12, Xuan Thoi Son Small Scale Arts & Crafts Group, National Road 22Xuan Thoi Son Village, Hoc Mon District, Ho Chi Minh City
This document is only current as of the last updated date stated below and is valid only for use in Vietnam. It is important that you always refer to the currently available information at the URL below to provide the most current product information at the time of use. Additional literature such as Contractor Manuals, Technical Bulletins, Detail Drawings and detailing recommendations and other relevant documents are also available on Information found on other websites must not be relied upon, as they may not be up-to-date or applicable to the conditions in your location and we do not accept any responsibility for their content. If there are any conflicts or if you need more information, please contact GCP Customer Service.

Last Updated: 2022-10-14