Does Lime Mortar Stop Damp?

Lime Mortar for Damp Proofing

It is important to first understand what type of damp the building is dealing with.

• Rising damp – this is where moisture in the ground moves up the house through the small spaces between permeable building materials such as bricks.

• Penetrating damp – occurs as a result of structural building problems (such as faulty guttering) where water puddles, saturates and absorbs through the exterior wall, causing brown patches to form on the inside wall.

• Condensation – where the warm interior air makes contact with a cooler surface, such as a window or sometimes the wall itself.

Due to the porous nature of lime mortar, in older buildings especially, it has helped to promote the evaporation and escape of moisture, something of which modern buildings with standard cement don’t have.

Most modern buildings’ insulation materials don’t mix well with water. Water molecules will collect in the small gaps within the insulation and create a cold bridging, which is a big causer of damp.

A breathable lime mortar wall can help combat this problem, by offering water and moisture a means of escape. This type of breathable render is hygroscopic and porous, allowing water and excess moisture to enter and store without causing damage. This will prevent it from reaching the insulation which could have a huge positive impact on the building’s damp proofing.