
Performance Wintermix Mortar & Render
A multipurpose hydraulic lime mortar for general building, pointing and rendering in colder weather conditions with a medium texture and refined buff coloured finish.
"*" indicates required fields
More about Performance Wintermix Mortar & Render
Cornerstone Performance Wintermix is a dry ready mixed multipurpose natural hydraulic lime mortar, render and plaster formulated explicitly for work in challenging cold environmental conditions. Available in the colour buff.
Engineered with precision, using 100% pure natural hydraulic lime, natural sands, and additives to create a high-performance winter work multipurpose mortar, render and plaster. With improved workability, an accelerated set, and an enhanced cure, this mortar is designed explicitly to combat frost damage and limit the impact of frost crystals. Once the initial strength is achieved, strength development slows in line with a standard NHL mortar. Free of synthetic polymers and Portland Cement. Available as standard with Otterbein NHL2 or Saint-Astier® NHL3.5. Other binders and mix ratios are available upon request.
Well-suited for winter work applications which require additional support to combat the risks associated with winter work in challenging conditions.
- Features the behaviour of a traditional NHL mortar
- Contains no Portland Cement
- Contains no modern synthetic polymers
- Limits the impact of ice crystals to protect the integrity of the render
- Rapid initial strength gain supports frost resistance
- Minimised likelihood of shrinkage cracking
- Increased water retention for an improved cure
- Enhanced workability for those behind the trowel
Suitable for external use, where the binder strength is appropriate for the host background or surface.
Due to the initial rapid strength development of Wintermix, the NHL2 versions should be treated as an NHL3.5 mortar and the NHL3.5 should be treated as an NHL5 for specification purposes. Appropriate for various project types, including conservation, renovation, or restoration. Relevant for building, pointing and coarse render coat applications in cold environmental conditions when paired with best practice curing and aftercare.
A 25kg bag yields approximately 14.5 litres of mortar and covers roughly 1.5m² at a 10mm thickness for pointing applications. On-site trials are advised for the best yield indication for your specific project.
As natural products, our kiln-dried sands may exhibit variations in colour, texture, and shape. While these variations are minimal, when colour consistency is crucial, we strongly advise each elevation is completed using material from the same batch.
Supplied in 25kg polythene-lined and colour and batch-coded paper bags for easy identification on-site. Palletised for ease of transport, storage, and handling. FIBC tonne bags are also available.
Do not use in temperatures below 5°C or above 30°C, or if freezing conditions are predicted within the following few weeks, including wind chill. We always advise following best practices for curing and protecting fresh lime renders and plasters. Protect from adverse environmental conditions, including frost, rain, direct sunlight and drying winds.
Store in covered and dry conditions, protected from environmental conditions, including water, damp or frost and clear from the ground. Always reseal packaging if product is still present.
Always read the available documentation before use. See the Download Documentation section below for more detailed product information, application guidance and datasheets.
Related products

Performance Roofline Medium Fast Set Mortar
A quick-setting mortar with a medium texture and tan-coloured finish for rooflines requiring support against slump or sag.
View Product
Performance Tanking Render
A ready mixed waterproof natural cement tanking render to prevent water penetration of internal and external masonry.
View Product
Newbuild Coarse Mortar & Render
A multipurpose hydraulic lime mortar and render with a coarse texture and refined buff colour finish for pointing or coarse render coats.
View Product