Lime plaster and render are traditional coatings that let moisture pass through the wall rather than trap it, which matters enormously on solid-wall and timber-framed buildings that were designed to breathe.
It's one of the few materials on this site where using the wrong alternative doesn't just look wrong — it can cause the exact damp problem it was meant to prevent.
Where lime is the right call
Wealden hall houses, weatherboarded and timber-framed cottages, and most pre-1919 solid-wall buildings across Kent were built to work with a breathable lime finish, and that's still the correct specification for them today.
It's also the right call wherever a building has a history of damp that turns out to be caused by a previous cement render or gypsum plaster trapping moisture in the wall — replacing the offending coating with lime is often the actual fix, not a cosmetic upgrade.
Listed buildings will very often require lime as a condition of consent, since it's considered the appropriate traditional material for the building's construction.
Where it's the wrong call
On a modern cavity wall with no breathability requirement, there's no functional reason to specify lime over standard gypsum plaster internally — it costs more, takes longer and buys you nothing the wall actually needs.
It's also the wrong call if the client wants a fast-turnaround finish. Lime cures in stages over weeks, and trying to compress that programme to suit a deadline produces a coating prone to cracking and failure.
Breathability and suction control
The key property is vapour permeability — lime allows moisture that gets into a solid wall, from driving rain or rising damp in the ground, to migrate back out and evaporate rather than becoming trapped behind an impermeable layer.
Suction control matters just as much as the material choice: a highly absorbent background like old brick or cob needs to have its suction managed, usually by dampening or a scratch coat, or the lime dries too fast and fails to bond properly.
What we specify instead when lime doesn't fit
On modern cavity construction with no breathability need, standard gypsum plaster remains the sensible, cost-effective internal finish.
Where a fast programme genuinely can't accommodate lime's curing time and the wall is not a breathability-critical solid wall, we'd discuss the trade-off openly rather than force lime onto a job it doesn't suit and rush its cure.
Common questions
How do I know if my house needs lime rather than standard plaster?+
It generally comes down to the wall construction — solid brick, stone, cob or timber-framed walls built before around 1919 usually need breathable lime, while later cavity-wall construction generally doesn't. We check this on the site visit before recommending either.
Is lime plaster more expensive than gypsum plaster?+
It generally costs more and takes longer to apply due to the multiple coats and curing time between them, but on a building that needs breathability, the alternative — trapped damp and recurring repairs — costs considerably more over time.
Can lime plaster be used just on one damp wall rather than the whole house?+
Yes, it's common to specify lime specifically on walls with damp history while leaving unaffected modern walls as they are — the two systems can coexist in the same building as long as they're not mixed on the same wall.
Get advice on plaster specification for your property
Free visit to assess your wall construction and any damp history before recommending lime or standard plaster.