01746 862 640

Damp Proofing Old Houses

We see and hear about damp problems in old houses all the time.  If we had a pound for every time someone rings about a damp problem, we'd all be very rich.  

Damp in old houses is perhaps one of the most mis-understood scientific disciplines within the building industry.  It has become a fertile breeding ground for a shark infested ocean of 'timber and damp surveyors', 'injection damp proofing contractors', and horrible little salesmen running around with 'damp meters' trying to pursuade you that their high readings indicate 'a broken down damp course' and 'rising damp'.  One thing is certain - you will not have the mythical 'rising damp' - and your damp course won't have broken down - any more than the moon is made of cheese.  You do NOT need any Chemical Damp Proofing.

This horrible, fraudulent industry has a very slick marketing engine which promotes all sorts of injection creams, siliconates, damp sticks, electric osmotic damp courses, tanking slurry, salt retardant, damp proof plaster and so on, mostly with equally fraudulent 'BBA Certificates' which purport to say the silly thing actually works.  Amazing how the BBA (British Board of Agrement - and privately owned by the way) can't reproduce rising damp, but can still approve a whole slew of products that purport to fix this fictional problem. The whole corrupt, chemical soup is one enormous con job on the British public. Companies like Rentokil, Peter Cox, Timberwise, Kenwood, Safeguard, Dampco and many others, for years have been selling damp proofing, under a thinly veiled cloak of respectability called the Property Care Association.  Avoid all of them as you would a shark infested tank.

Why do we get 'damp problems' and what are they?

Most 'damp' issues fall into broad categories:

External influences:  High ground levels, leaky gutters, roof leaks, driving rain against old stone walls, broken or leaky drains, water splashing against the base of walls, blocked sub floor vents - all physical things easily fixed.

Internal moisture stress: High levels of moisture internally - lack of ventilation to kitchens, bathrooms, bedrooms. This is also compounded when under floor ventilation is restricted.

Salts:  Hygroscopic salts that are present within masonry - whether it is stone, brick or mud brick.  Salts are produced in huge quantities in chimney stacks - so any wall with a chimney in it will potentially have 'damp' patches which are actually salts, and nothing to do with damp.

Why does plaster and paint peel and look manky?

Old buildings used breathable materials - moisture could travel freely through the materials and evaporate. There's always SOME moisture in nearly everything - your doors shrink and swell - they don't rot - but their moisture content increases and decreases with the seasons - so do nearly all building materials.  What people don't realise is that water as a gas is harmless - it has tiny, light molecules that just pass through things, together with oxygen and nitrogen.  Great - so when is it a problem?  

Temperature, Watson - it's all in the temperature....

If you drop something below Dew Point (the temperature at which condensation forms - or water the gas turns into water the liquid) it gets wet if there is any gaseous water present.  All walls will have moisture in them doing no harm.  If they get cold, they'll get damp. Typically right at the base of walls - where they are near the ground, or in very cold exposed places like under bay windows or top corners of buildings like bedrooms, or window reveals in winter.  This is where 'damp' appears - sometimes as mould, sometimes flaky paint and plaster. This isn't 'rising' - its just appearing where the wall is cold..

So what's the solution?  

We could warm the wall up - keep the heating going at a constant very low level just to stop fluctuation in the temperature of the walls.  Remove humidity - so ventilate, extract the kitchen, extract bathrooms better, make sure sub floor areas are ventilated properly.  And lastly:

Remove any 'unbreathable materials' like gypsum plaster internally, cement render oustside, cement pointing that stops the mortar joints from losing water.  Take wallpaper off that traps moisture (its plastic coated) Dont use plastic dulux emulsion paints - use clay based paints like the Earthborn range.

Just by making the building breathable, your problems will start to disappear. It's not rocket science, It's not expensive.  

It also Makes Sense!

Damp proofing old houses is not only expensive, it is daft. It is not needed.  The only winners are the sharks at the Property Care Association who want to sell millions of pounds worth of useless toxic chemicals every year to what used to be an unsuspecting public.  Thankfully, the message is getting out there now, and people aren't being conned any more.  I hear the chemical companies are laying off employees - that's the best news we've had for years!

Here's a link to the Heritage House Website , where you can amuse yourself for hours reading about these idiots and the things they do to people..

If you have damp problems, and feel that you need help, we can assist with a Timber and Damp Survey or if you are one of those unlucky ones who live in London, we have a specialist who deals with London Damp Surveys.

Regulated by RICS