Damp walls in old houses

It’s the height of summer as I write this explanation of damp walls in old houses.

Summer is normally the time when people ignore the damp patches which seem to have reduced a little with the heat and hope by some miracle that they have cured themselves this year.

Of course as soon as we have the rains in October and November the attractive old house will soon take on that damp smelly depressing feeling that you have put up with too long.

I am sure that you will have painted over it a couple of times to no avail. maybe applied a new wonder product from the D.I.Y store. Still those damp patches and flaking paint persist.
Before we look at how to fix the problem lets look at some typical scenarios.

Below is an old house wall that is in a small courtyard. The green stain is algae and it is being fed with nutrients that leached from the soil between the stones making up the house wall.

Damp walls in old houses
Algae growing on house wall

No it’s not cement it is just soil. The soil holds the moisture from the rain (making the wall damp) and the rain washes the algae down the wall. It has not dried because it is in a courtyard which protects the wall from the sun and wind so they don’t dry out.

Damp walls in old houses – Then we have the dreaded flakes!.

bubbles of paint
Damp walls and old houses

Flaking paint on internal walls. This is a massive problem in Portugal and it is the clearest sign of damp walls in old houses.

The moisture is inside the walls and evaporates to the atmosphere normally when heating is used inside an old house. The moisture pushes off the paint exposing the bare stone or plaster behind.

 

These black or brown spots are algae which has formed on a damp area of an internal wall. The wall isn’t actually damp. What is happening is that this wall is not insulated and the part that has the black marks on it has been wet with condensation. The cold on the outside of the house has caused the humidity in the house to condense into water on the wall. The warmer house air causes the mildew to grow making an unsightly mess.

 Castelo Construction tackle damp walls in old houses. Don’t leave yours another year.

Contact us  info@casteloconstruction.com

www.casteloconstruction.com

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https://www.casteloconstruction.info/category/damp-house/

https://www.casteloconstruction.info/2015/07/22/property-survey-3/

https://www.casteloconstruction.info/2015/05/13/cold-damp-portugal/

https://www.casteloconstruction.info/2015/07/21/injecting-damp-proof-cream-portugal/

https://www.casteloconstruction.info/2014/12/18/humidity-home/

 

 

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