SILCOR® 900MP (US Version)

Rapid-set, spray-applied, liquid waterproofing membrane for podium decks, green roofs and terraces

Product Description

SILCOR® 900MP is a premium performance two-component spray-applied seamless waterproofing membrane that cures within 2 minutes to form a high-strength, elastomeric, and fully-bonded waterproof membrane. SILCOR® 900MP is extremely durable with excellent wear and chemical resistance and does not normally require additional protection against mechanical damage.

Product Advantages

  • Fast Cure – will accept foot traffic after 2 mins.
  • Seamless – continuous waterproofing integrity.
  • Productivity – spray-applied for maximum coverage per day.
  • Fully bonded - resists water tracking beneath the membrane
  • Non-flammable – 100% solids. Solvent free.
  • Low Odor – low VOC.
  • Elastomeric - accommodates movements and bridges concrete shrinkage cracks.
  • Durable – tough with excellent wear and damage resistance.
  • Chemical Resistance – excellent fuel and chemical resistance.

Principal Applications

New and remedial waterproofing for:

  • Podium decks
  • Terraces
  • Walkways and foot bridges
  • Balconies
  • Green/Planted roofs
  • Planters
  • Rough concrete surfaces


SILCOR® 900MP spray-applied waterproofing system is designed for use as a fully adhered waterproofing layer on new and existing elevated structural decks. Structural decks should be sloped to drain a minimum of 1/8 in./ft.

    System Components

    • SILCOR® 900MP – premium performance two component, spray-applied seamless waterproofing membrane
    • SILCOR® Primer EPF – two-component epoxy primer (for temperatures 40°F-80°F)
    • BITUTHENE® Liquid Membrane – two component elastomeric liquid applied detailing accessory
    • PREPRUFE® Tape – reinforced pressure sensitive tapes for detailing

    Details shown are typical illustrations only and not working drawings. For assistance with working drawings and additional technical advice please contact GCP Technical Services


    SILCOR® 900MP liquid waterproofing should only be applied by experienced, trained contractors. Effective liquid waterproofing application starts with a good surface preparation of the substrate.

    Surface Preparation

    All grease, curing agents oil or other contaminants that can affect adhesion of the membrane to the surface need to be removed prior to application of SILCOR®. Grease, dirt and grime can be removed using high pressure water cleaning provided sufficient time is allowed for the residual humidity and water to dissipate. Sandblasting is not effective on contaminated concrete.

    After cleaning, the surface should be prepared to open the pores and make the surface ready to accept the primer. The preferred and most common method is sand or grit blasting. Surface preparation for specific substrates is discussed below.

    Concrete should be allowed to cure for at least 28 days. Concrete moisture content must be less than 5% prior to application of the SILCOR® primers. Moisture content must be checked using appropriate meters and test methods.


    Priming should be completed prior to applying SILCOR® 900MP.

    • Add the complete B-component to the A-component to assure correct mixing ratio.
    • Mix with a slow turning mixer (less than 300 rpm) mix until a solid, streak free color is achieved in order to obtain a homogeneous mixture.
    • The primer should be applied to the surface by brush or roller immediately after mixing.
    • Pour the primer onto the surface in a zigzag trail.
    • After pouring onto the surface, the primer should be evenly distributed onto the surface with foam rubber squeegees and rolled into the surface, within the pot life, using Perlon rollers.
    • The primer should be evenly distributed at 10 mils thickness with complete coverage of the surface.
    • If the surface is very porous and absorbs primer leaving an open surface, additional primer must be added in this area within the pot life or recoat time of the primer.
    • The recoat window of the primer is typically up to 24 hours. This window is influenced by ambient temperature and humidity. When the recoat window time is exceeded before the membrane is applied, re-apply a new layer of the SILCOR® Primer.
    • The recoat window of SILCOR® Primers can be extended by broadcasting dry quartz silica sand into the primed surface. Broadcast sand to full saturation. Use sand of 16/30 mesh for coating thickness of up to 80 mils. For larger coating thicknesses larger grain sizes can be used. Remove surplus sand and partially bonded particles with a scrubber after the primer is dry to the touch.

    For complete instructions and descriptions on SILCOR® Primers, consult the separate technical data sheets.

    Spray Equipment and Temperature

    SILCOR® membranes are rapid setting high performance materials designed to be used with high-pressure proportioners such as Graco® Reactor E-XP2, H-XP2, and H-XP3 or similar high-pressure plural component spraying equipment. Both RESIN and ISO components are supplied directly from drums with diaphragm or T-pumps ensuring continuous flow of material to the machine. Due to the high reactivity of the system, components are kept separately until they reach the spray gun mixing chamber. The components are designed for a 1:1 mixing ratio by volume. A highyield air compressor is needed to operate the pumps and the spray equipment. See your manufacturer equipment requirements for appropriate air compressor specification and settings.

    Ambient application temperature must be between 40°F and 90°F. Substrate temperature should must be between 40°F and 175°F and exceed the dew point temperature by a minimum of 5°F.

    SILCOR® Resin components are pigmented and need to be mixed before application with an air driven cork-screw type mixer or similar. Mix at low speed to avoid air entrapment until a homogeneous color is obtained. After mixing, it is recommended to keep the blend agitated using a slow turning mixer in the drum. SILCOR® Isocyanate components are supplied ready to use and do not need pre-mixing.

    They are moisture sensitive and need to be protected from all sources of moisture.


    SILCOR® membranes are sprayed multi-directional (up-down / left right) in several coats to obtain uniform coverage and membrane thickness. Hold the gun perpendicular to the substrate at a distance of 24 to 35 inches. When applying, care is required at the overlap to ensure an even coverage of the overlap area. Spray applied SILCOR® membranes are applied at a minimum thickness of 80 mils. In order to achieve uniform membrane thickness, a smooth and constant gun speed is required by the gun operator.


    For complete detailing instructions, refer to SILCOR® 900MP standard details.

    Chemical Resistance

    SILCOR® 900MP offers protection to a wide range of chemicals. Contact GCP for specific details and recommended applications.


    Apply SILCOR® 900MP directly to structural surfaces. Do not apply SILCOR® 900MP over lightweight insulating concrete. Insulation, if used, must be installed over the membrane. 


    GCP and trained contractors can provide warranties for individual projects. Contact GCP for further details.

    Health and Safety

    For SILCOR® 900MP, SILCOR® Primer EPF, and SILCOR® Primer EPS read the product label and Safety Data Sheet (SDS) before use. SDS’s can be obtained from GCP Applied Technologies.


    SILCOR® 900MP (Resin) 400 lb - 55 gal drum
    SILCOR® 900MP (Iso) 495 lb - 55 gal drum
    SILCOR® Primer EPF (Part A) 7.1 lbs pail - approx. 0.7 gal
    SILCOR® Primer EPF (Part B) 4.0 lbs pail - approx. 0.5 gal
    SILCOR® Primer EPS (Part A) 12.1 lbs pail - approx. 1.5 gal
    SILCOR® Primer EPS (Part B) 9.9 lbs pail - approx. 0.9 gal
    Storage Store between 40°F & 80°F
    Shelf life - SILCOR® 900MP 12 months

    Physical Properties

    Tensile Strength 4090 psi ASTM D412
    Tear Resistance 487 lb/in. ASTM D751
    Adhesion to concrete > 479 psi1 ASTM D4541
    Low Temperature crack bridging Pass ASTM C836
    Shore Hardness 91A ASTM 2240
    Abrasion Resistance (Taber Wear index) 255 mg2 ASTM D4060

    1. Tested on prepared, primed, and sand blended concrete or steel.
    2. H18/1000 cycles/1000g

    Liquid Properties

    Viscocity - Resin 400-600 cps1 Brookfield Viscometer
    Viscocity - Iso 800-1200 cps1 Brookfield Viscometer
    Solids Content 100% ASTM D1644
    Density (Resin, Iso) 8.6 lb/gal
    9.2 lb/gal
    ASTM D4541
    Coverage Rate (80 mil thickness) 16.4 ft2/gal
    1800 ft2/kit
    Gel time 5 sec1 internal
    Tack free time 8 sec1 internal
    Trafficable (foot traffic) 2 mins.1 internal

    1. Measured at 77ºF
    All declared values shown in this data sheet are based on test results determined under laboratory conditions and with the product sample taken directly from stock in its original packing without any alteration or modification of its component parts. | North America Customer Service: 1 877-4AD-MIX1 (1 877-423-6491)

    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.

    BITUTHENE, PREPRUFE, and SILCOR 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 2018 GCP Applied Technologies Inc. All rights reserved.

    GCP Applied Technologies Inc., 62 Whittemore Avenue, Cambridge, MA 02140 USA.

    In Canada, GCP Canada, Inc., 294 Clements Road, West, Ajax, Ontario, Canada L1S 3C6

    This document is only current as of the last updated date stated below and is valid only for use in the United States. 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: 2019-03-08