How do you know if the damp course is really working?

Are you in a dispute with a contractor?

Have you had a damp problem for a while and no damp specialists can fix it?

Is it rising damp, penetrating damp, condensation, a leak or salt damp?

Complete Preservation are here to help, and we can guarantee to solve the problem using The Building Research Establishment method ( BRE Digest 245) with laboratory analysis and a long term guarantee.

  • We take a moisture profile of the wall using a slow speed drill and go past the last signs of damp
  • All samples after drilling are sealed in an air tight container and are labelled
  • Samples are then individually weighed on laboratory scales
  • Samples are then placed in a desiccator (humidity chamber) for a couple of days @75%RH
  • Samples are re-weighed and recorded to see if they have gained weight or lost weight
  • Samples are then placed in a laboratory oven and dried until all moisture has evaporated
  • Samples are then tested for Nitrates and Chlorides
  • We now have 3 readings, a profile and salt testing results which will give us 100% correct diagnosis
  • Gravimetric damp testing diagnosis

Gravimetric Testing BRE 245

Damp expert Wiltshire



BRE DIGEST 245 survey with salt analysis


The above picture shows that there is no free moisture (no damp), the problem is the hygroscopic salts distributed in the wall from previous rising damp. These salts are hygroscopic (nitrates and chlorides)  and the plaster needs to be replaced.


The above picture shows how a damp meter can get confused with hygroscopic salts and moisture

Gravimetric damp testing to BRE Digest 245

Oven dry method testing for dampness BRE 245

For further info and to contact us contact us at

01225 769215

Posted by Complete Preservation


  1. That gives everyone totally peace of mind, no more worries, brilliant


    1. You need to filter out the good guys and the cowboys, unfortunately I am seeing more and more people being ripped off for rising damp problems!


  2. […] Here is a link to a previous post on BRE Digest 245 […]


  3. Please could you help us out.
    We have had a number of damp surveys carried out previous to the repair work we had carried out. We eventually decided on lime render and plaster and no damp proof course. We now have the same problem again, not quite as bad though. This seemed to work at first, and has been going for 5 years. We have contacted the company that carried out the work and they said the wall is still drying and could take years. What would you recommend we do?


    1. Hi Pauline

      It is possible you may still have a rising damp problem or a hygroscopic salt contamination problem.
      Lime plaster is a marvellous product which we use on a regular basis, some people that only use lime plaster and have no means of the identification of rising damp and the amount of salt contamination let the client down. This maybe because they don’t know any better, the only way I personally decide is by BRE Digest 245. This will tell us what we need, and explain the risk to the client. Sometimes the walls will only have free moisture from surface water or a leak, sometimes rising damp and hygroscopic salt contamination, and if it is a Grade1 listed building these will have to be poulticed because the hygroscopic salts will migrate through.
      Drop me an email and we can discuss further.
      Hope this helps


  4. […] The most reliable way to test a wall for damp is to drill deep into it and take a sample for gravimetric testing. […]


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