DIY Doctor UK DIY Forums

We have recently had a new (and much more powerful) heating system installed in our Victorian sandstone home and have noticed a sudden build up of salt crystals on an exterior wall. Historically this had been an issue (long before we moved in 18 months ago looking at the wall) but to nowhere near the same extent and seems to have been amplified by our home being much warmer compared with outside that it previously has even been.

Externally the buildup occurs in 2 places. The conditions on the internal side of the wall are as follows:

(1) the salt follows the line of the stairs down into the cellar - internally there is a wooden board fixed to the wall at the point where the salt begins (below the line it is just painted stone as in the rest of the cellar).
(2) the second salt area is on the other side of the wall to our kitchen cupboards. Similarly these are fixed internally to some sort of board.

I suspect that the moisture is being trapped behind the walls internally due to the boards and then forced out through the stone.

I would very much appreciate any opinions on how to mitigate the issue, and prevent future buildup!

Cheers

Hello Akker
I looks like by installing new heating system you start drying process. There is always salt in water, when water moves it take salt with it. Sometimes if there is salt contamination in walls water can be just absorbed from air. If you have good DPC in your building you don't need to worry - it should stop when all dry out. But if is old house and DPC gone by heating you create more potential to absorb more water from ground and this process will not stop. Unless you use device who change polarity and create diverted osmotic process.

sounds like the damp has decided to leave your house as it doesn't like the heat but is struggling to get passed the boards,I would leave it awhile see what happens but wash off the excess