Damp in Old Houses
Damp in Old Houses – Damp, Condensation, Penetrating Damp, rising damp
The dilemma of dampness caused by condensation in old houses
It’s not just a dilemma for the house owners it’s also a dilemma for those of us who are tasked with curing or sorting it out.
To explain in more detail.
Over the last 60 years we have been fed a lot of miss information from companies selling products to protect ? our home from the problem of damp.On the other side of the coin we have also been fed information that is not technically correct and could also be termed hearsay or miss-information.
An attempt to make things clear ALL HOMES HAVE DAMP yes even your 1 million pound mansion.
That is to say ALL HOMES HAVE HUMIDITY – even dry homes.
The difference is in the levels of humidity that is on the internal walls and in the air. If the homes internal air is around 20% humidity you don’t notice it and the house and walls feel dry.
If the homes internal air is around 45 to 50% humidity then you will start to see tell-tale problems caused by CONDENSATION (not rising damp)
Any higher that 50% and you will see interior damp tell tales. Make no mistake condensation is a nasty ugly thing that makes houses hard to live in comfortably and can produce conditions where paint and wallpaper fall off walls, insects abound and microscopic spores breed which can cause respiratory problems to inhabitants.
Damp in Old Houses. There is a trend at the moment where people are saying that it’s the fault of the cement used in the last 60 years to build and render walls that makes them not able to breathe and therefore dry out. What you should use they say is lime mortar and clay based paints so that your home can breathe. This breathing notion is very misleading and is often accompanied by Ecological, planet saving references which are even more miss leading.
Looking from another angle. Old houses used to have open fires providing more ventilation than heat.
They also had badly fitting windows and doors providing a lot more additional ventilation. People often smoked in the house so windows were left open providing even more ventilation. There was no insulation in the houses at all. The result of the above is that. The houses felt very cold (frost on the inside of the windows) and damp enough that clothes would become “musty” if left in wardrobes. Householders invented many ingenious methods to stop cold drafts.
These houses were uncomfortable to live in.
Which is why we moved to insulated homes with central heating and hot water throughout the house.
In the list of main causes of damp in your Portuguese home.Provided in part 1.
Lack of ventilation is listed and this is a major culprit in creating the condensation that we see as damp inside our homes.
We don’t want to go back to living in the past and are used to our creature comforts so how do we achieve the best of both worlds a warm dry home !
Ventilation is the answer. Think of over ventilation and you are still a little way short.
Modern houses have bathrooms, showers, cooking, people and pets breathing, clothes washing, drying and fridge freezers all of which pour large amounts of water vapor (humidity) into the homes atmosphere. The only way to get rid of this is with adequate ventilation.
If you insulated every part of the home the airborne water vapor would find the coolest part like a door handle on an outside door or glass on a window and condense on this forming a puddle inside the house.
If you see condensation inside your windows open the doors and windows until it goes and a for a good while after.
Opening two doors or a couple of windows is best to provide a through draft which moves more damp air out.
Our third part of the blog will look at managing humidity in stone build houses
Check our www.casteloconstruction.com to see actual damp solutions.
