The importance of anti-salpetre lime

Pozzolanic (PZ) lime: absolutely indispensable for restoring façades with walls suffering from rising damp or exposed to sea spray.

The problems

Traces of saltpetre, efflorescence and damaged renders or masonry over areas with the same characteristics, at varying heights and generally running from the ground up on exterior but also interior walls (basement, entresol, ground floor, etc.).

Why ?

The walls are exposed to various outdoor or indoor conditions.

  • Salts that are naturally present in the soil move upwards within the wall through capillary action as old buildings do not have moisture barriers.
  • The rainwater can bounce off the ground covering outside (asphalt, concrete, etc.) and splash onto the bottom of the wall which is then gradually damaged through repeated rainfall.
  • The rainwater on the ground can also run towards the bottom of the wall, more generally due to an improperly sloped pavement or outside ground area.

The consequences


Masonry stones may come loose and render may crumble off, with even whole sections of affected render falling off. The wall is no longer protected from the rain, which easily seeps into the wall and exacerbates the problems.

The essential role played by plinths and wall bases

This explains why buildings that are now part of our heritage were designed with this potential water damage in mind (over the medium and long term). They all have an over-dimensioned plinth or wall base designed according to local practices and the readily-available building materials.

‘Over-dimensioning’ was, and still is, an attractive and simple means of delimiting an area that would have been especially affected. This clearly delimited area is cost-effective and practical as it enables only a part of the façade to be repaired with no unsightly traces of repair!

Keep it looking beautiful

Every time, this procedure gives the overall building a visual grounding and only adds to the aesthetics of the façades.


Treating the wall bases for the long term

Preparing a salt-resistant mortar in-situ. Tradical has designed a PZ lime which gives time-tested longevity to structures, from masonry through to finishes.

3 reasons to choose PZ

Only one type of lime whatever the hardness of the material to be laid and/or rendered

Compatible with all local sands

Manual or mechanical application

Satisfied customes

House in Palavas-les-Flots, France : Damp rising through capillary action is inherent to the way this traditional house, located in a seaside town, was built. This condition was exacerbated by an asphalt pavement which increased the concentration of salts in the walls of the building. Tradical PZ plays its filtering role to the full here, and allowed for a finish that is resistant to rainfall splashes at ground level. Guaranteed to last over time.

Traditional French house in the Creuse : Due to the presence of saltpetre on the outer walls and the supporting walls, Tradical PZ was applied up to two metres high inside and then rendered using a Tradical hemp render.

Anti-salpêtre Tradical lime

Tradical PZ

  • Grey lime
  • Class HL 5 building lime according to building lime standard NF EN 459
  • For lime masonry
  • For brown coats and finishes
  • Manual and mechanical application
PZ 3D copie

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