This website uses cookies to ensure that we give you the best experience on our website.
By continuing to browse the site you are agreeing to our use of cookies. To find out more click here

Weber Saint-Gobain - Official website of the company

triple strength medusa

triple strength medusa
triple strength medusa

Product Benefits

  • To provide economical and durable renderings and mortars with increased water repellence
  • To reduce surface water absorption and hence staining of rendering

Water-repellent admixture for cement mixes

Product Features

About this Product

triple strength medusa is an admixture in white powder form. Its addition to a mortar mix will improve the water repellence of the finished work

Features and Benefits

▲ Provides increased water repellence ▲ Assists in providing even suction in undercoats ▲ Reduces water permeability ▲ Reduces surface water absorption


triple strength medusa is not suitable for use with high alumina or calcium aluminate cements

Technical Data

BS EN 13914-1 Design preparation and application of external rendering and internal plastering and BS 8000-10 Workmanship on building sites. Code of practice for plastering and rendering, should be followed at all times.

Technical Services

weber's Customer Services Department has a team of experienced advisors available to provide on-site advice both at the specification stage and during application. Detailed specifications can be provided for specific projects or more general works. Site visits and on-site demonstrations can be arranged on request.

Technical helpline
Tel: (01525) 722110
Fax: (01525) 718988

Sales Contact

Sales, England and Wales
Tel: (01525) 722100
Fax: (01525) 718988

Sales, Scotland
Tel: (0141) 445 0121
Fax: (0141) 445 0122

Sales, Ireland
Tel: (028) 9335 2999
Fax: (028) 9332 3232


Send or download the documents

You can either send the documents to an email address, or download it

Preparation & Application


Preparation and Application should be in accordance with the specification and relevant British Standards for the work to be carried out.


Mix triple strength medusa at a rate of one 330 g sachet per 50 kg (2 x 25 kg bags) of cement.

Mix the powder with the cement and aggregates in the dry state. Thorough mixing is essential, but air entrainment and possible loss of strength may occur if machine mixing is unduly prolonged once the water is added. Only clean, sharp, well graded sand should be used for rendering.

In all cases the strength of the mix should be in accordance with the specification and British Standards applicable to the particular work to be carried out.

Packaging, Health & Safety


triple strength medusa is available in 330 g sachets (20 per carton) or 5 kg sacks.

Coverage / Yield

One 330 g sachet is sufficient for a mix containing 50 kg cement. 1 kg is sufficient for a mix containing 150 kg cement.

Storage and Shelf Life

Store in dry conditions.
Shelf life of unopened sachet is at least 12 months.

Health and Safety

Essentially not hazardous.
Not harmful during normal use.
After contact with skin, wash immediately with plenty of water.
In case of contact with eyes, rinse immediately with plenty of water and seek medical advice.
Keep out of the reach of children.
For further information, please request the Material Safety Data Sheet for this product.