BETEC® 350

Waterproof cementitious compound for sealing tie-bar holes


BETEC® 350 is a single component cementitious compound which is polymer modified and fibre reinforced. It is a rapid setting, high strength, waterproof compound used to seal tieholes that are created by formwork tie bars.



Store in dry, frost free conditions in unopened containers. Do not allow to freeze.

Substrate Preparation

The area must be free from dust; oil, grease, dirt and all lose material. Smoothsurfaces should be roughened by mechanical wire brushing or similar. Any remaining plastic sleeve must be either removed entirely or cut back and removed 40-50 mm from the concrete face. The tie bar hole should then be plugged with a compressible stopper. The tie-hole should be saturated with clean water and any excess surface water removed. Use warm water if the concrete is new.


Only mix a sufficient amount that can be used within a 20 minute working life. Mix at a powder to water mix ratio of 6: 1 by volume. Always add powder to water. If mixing quantities of less than 2 kg, mixing can be done by manually. Mix for 4-5 minutes and ensure the powder is fully mixed in. For larger quantities use an MR2 paddle mixer with a slow speed drill. Mix thoroughly for 2-3 minutes to achieve a homogeneous mix.

Pack Size: 8kg
Yield: 4 litres per 8 kg pack
Coverage (26 mm diameter tie bar): 110 holes per 8 kg pack
Mixed Colour: Grey
Mixed Density: 2150 kg/m3
Min. Application Thickness: 5mm
Max. Application Thickness: 50mm
Min. Application Temperature: 5°C
Max. Application Temperature: 35°C
Working Life: 20 Minutes at 20°C
Compressive Strength:  
1 hour: 8.0 N/mm2
1 day: 38.0 N/mm2
7 days: 50.0 N/mm2
28 days: 60.0 N/mm2

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.


  • Rapidly sets in 30 minutes at 20°C
  • Waterproof, able to withstand 10 bar pressure
  • High bond strength to substrate
  • Shrinkage compensated
  • Low permeability due to polymer modification
  • Fibre reinforcement improves strength


Apply by hand ( always wear protective gloves) or with a trowel. Ensure the compound is well compacted into the tie-bar hole.


Normal concreting procedures must be followed. The surface of the compound must be protected from strong sunlight and drying winds using polythene sheeting, damp Hessian or similar.


All tools should be cleaned with water immediately following use.

Health and Safety

Read the product label and Safety Data Sheets (SDS’s) before use. Users must comply with all risk and safety phrases. SDS’s can be obtained from GCP Applied Technologies or from our web site at | United Kingdom customer service: +44 (0) 1480 478421

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.

BETEC 350 is trademark, 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 the UK, Ipswich Road, Slough, Berkshire, SL1 4EQ, UK

This document is only current as of the last updated date stated below and is valid only for use in the United Kingdom. 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: 2021-02-05