Rising Damp

Rising Damp is a MYTH !

Buildfix have spent years studying and investigating the causes of damp. Initially sold on the idea that most problems were caused by rising damp and installing a new chemical DPC, knocking off the plaster to a height of 1m, applying a waterproof cement render and finishing off with a gypsum top coat was the answer, Buildfix originally moved towards that solution as an additional business offering. The more we tried to understand what we were doing and why? the more we realised that “Rising Damp is a myth”. Don’t get me wrong Damp is a real problem, it blights the lives of many people and makes their living environment an unpleasant place to be but spending thousands on a Chemical DPC and cement render is not the answer.

A Myth! WHY?

The main reason is it’s not been possible to re-create it in a laboratory environment, capillary action, osmosis, different bricks, alterations to the mortar composition, non of them help to create rising damp. Some of our properties have survived for hundreds of years and then all of a sudden since the 1960’s the phenomenon of rising damp has risen.

Question :- Why does Venice not rot and crumble?

How are we initially Misled?

The infamous Damp Meter, When a Damp surveyor enters your property and applies a damp meter to your wall it bleeps quickly, screams an alarm or provides a digital display number which they interpret as ” You have a problem, you have rising damp”

Well Firstly a damp meter does not measure damp in non organic building materials!

Let me explain :- The damp meter was invented to measure moisture in wood. The device works really well in measuring moisture content in wood because the relationship between the moisture in wood and the minerals released by that moisture are relational and thats what the damp meter is reading.

How a Damp Meter works :- A damp meter measures the electrical conductivity between the pins, in wood, the more moisture, the more minerals released the greater the conductivity the wetter the wood. This is not the same for building materials

Moisture content in wood :- To add more fuel to the fire (pardon the pun) most moisture meters only display up to 36% as anything above that is not suitable for burning. Unseasoned timber contains 1 pint of water per kilo which needs to be burnt off before the log can burn efficiently. The more moisture a log contains the less energy it will release.

Measuring Moisture in Building Materials

To recap :- The pin moisture meter will only measure the electrical conductivity of the mineralised moisture on the surface of the building material. The greater the mineral deposit the less the resistance the greater the reading. The amount of moisture can remain a constant but if the mineral content increases the resistance will decrease and the reading will become higher providing a false reading of greater moisture content.

There are only 2 ways to truly measure moisture content in non organic building material,

  • Weigh the material wet, dry out the material and weigh it dry, the difference is the % of moisture
  • Weigh a sample of building material (in grams) use calcium carbide to convert the moisture to a gas. The relationship between the gas produced and the moisture % can be measured accurately and the output converted to % of moisture. The building material will be bone dry after this chemical reaction thus proving the total moisture content has been converted to a calibrated gas measurement.

Rising Damp, The Myth – Evidence

Below are 2 youtube videos by Peter Ward, a demon to the rising damp industry, a thorn in their side, we use the same practices and methods as Peter and they prove without a doubt that Damp really does exist, but rising damp doesn’t. At Buildfix we aim to get to the root cause of a damp issue. Our ethos is to solve the damp problem not mask or hide it.

Royal Institute of Chartered Surveyors – RICS damp expert Stephen Boniface defines the commonly accepted definition of rising damp before both he and fellow guest, Jeff Howell, claim ‘true’ rising damp doesn’t exist.

Construction lecturer turned author, Howell, cites his years of research and experimentation as evidence. He also questions the need for DPCs and claims chemically-injected ones are a ‘complete waste of time’.

The programme concludes that while rising damp is at best exceedingly rare, dampness in homes is a serious problem. The BRE methodology for testing for damp is illustrated, as is a discussion about the most likely causes of damp.

A further 2 Videos by Peter Ward providing evidence that rising damp is just not true

Chemical Injected Damp Course – ” A Complete Waste of Money”

Stephen Boniface, former chairman of the construction arm of the Royal Institution of Chartered Surveyors (RICS), has told the institute’s 40,000 members that ‘true rising damp’ is a myth and chemically injected damp-proof courses (DPC) are ‘a complete waste of money’

’Not only are chemically injected DPCs a waste of time, they are ineffective and grossly expensive. [Installing] damaging impermeable cement based internal renders…serve simply to conceal the problem in the wall behind.  For most historic buildings this is extremely damaging and irreversible.’

For a True Assessment of your Damp Problems Call 01785 472 023