Lime Renders & Mortars

Lime renders and mortars for traditional buildings

Lime render is the correct specification for heritage, traditional and solid wall buildings, and using cement-based products on them causes measurable damage over time. Licata supplies a full range of lime renders, lime mortars, dehumidifying lime systems and lime finishes for buildings that need to breathe.

Why lime rather than cement

Solid wall buildings were constructed to manage moisture rather than exclude it. Rain penetrates the outer face, and the wall dries outward between wetting events. That cycle works as long as the external finish remains vapour open.

Cement render breaks the cycle. It is comparatively impermeable, so moisture that gets into the wall, whether through cracks, rising damp or condensation, cannot leave through the face. It migrates instead, accumulating at the base of the wall or moving inward, and the consequences follow: decayed brick and stone, rotting embedded timbers, salt crystallisation behind the render, and eventually the render itself debonding in sheets.

Cement render is also rigid. Traditional buildings move seasonally in ways modern construction does not, and a rigid finish on a flexible substrate cracks. Those cracks admit more water than the render was ever going to keep out.

Lime remains vapour open and flexible. It allows the wall to dry, accommodates movement, and where it does crack, its self-healing characteristic allows fine cracks to close over time as free lime recrystallises.

Lime render systems for different conditions

Not every lime application is the same, and the right system depends on the condition of the wall:

• Dehumidifying lime systems for walls affected by rising damp and salt contamination, allowing moisture and salts to be drawn out and held within the render rather than reaching the surface
• Water-repellent lime systems for exposed elevations that need enhanced weather resistance while remaining breathable
• Basic lime systems for sound substrates requiring a traditional breathable finish
• Interior lime systems for internal walls in traditional buildings, including those with damp issues
• Lime micro coatings for fine decorative finishes over a lime base
• Ancient lime fixing systems for consolidating and repairing historic masonry

Conservation and listed buildings

On listed buildings and in conservation areas, lime is frequently a condition of consent rather than a preference. Conservation officers will specify lime-based materials and may require details of the mix, the aggregate and the finish before approving work.

Even where consent does not require it, lime is the technically correct answer on any solid wall building. The cost difference against cement is modest, and it is very much smaller than the cost of remedying the damage cement causes over twenty years.

Technical support and supply

Lime work rewards getting the specification right at the start. Our technical team advises on system selection for the wall condition, application sequencing and curing requirements, which matter more with lime than with cement-based products. Lime products are stocked across our six UK branches.