Dummer, Hampshire - Damp Proofing
Building Preservation & Lime re-pointing
One of the most frequent occurrences we encounter in traditional construction is 'low level damp', which can range in severity from a small patch through to completely decayed, salt contaminated plaster and rotten skirting boards that people can also be familiar with.
This was a small job that demonstrates the need to understand the nature of how traditional construction dealt with damp and when we were called to inspect an external wall of the sitting room in a property, the first step in assessing any suspected moisture damage in a traditional building is to examine the nature of the materials and the characteristics of the construction and methods used.
Upon lifting the carpet we could see that the original brick floor, in some places, had warped and risen up. There were visual signs of dampness at the base of the walls internally in the sitting room and also a musty damp smell coming through the carpet. The edges were showing signs of moisture ingress through the dark staining.
Externally we noted the earth levels and the soil was quite high in relation to the internal floor level, spoiling the brickwork and mortar, it had also enabled the roots of a well established climbing plant to migrate through the solid brickwork impairing the brick floor inside. Unfortunately and quite commonly we also identified a cement based mortar across the entire elevation and most extensively at the bottom of the wall, causing some bricks to spall.
We gently dug out some of the earth 150mm deep x 200mm wide from the base of the wall which was necessary to enable us to repair the damaged brickwork as a result of the invasive plant roots. We were not creating any drainage as such as the property has cast iron rainwater goods, instead we reduced the external ground levels very slightly to provide a small 'evaporation zone' for any moisture that is drawn up the solid masonry via capillary action, as we've established there is no Damp-Proof Course in the walls.
With attempts to gain a color match, we then used a lime putty mortar and carefully re-pointed the brick wall.