Upon the discovery of dampness, virtually anywhere in the property, most people automatically assume that it’s the result of a failure in some aspect of the external coverings; either that or a fault with the plumbing, which of course it sometimes is. 

They suspect the walls, the roofs, the gutters, the bath or the central heating system etc.  What they never consider is that sometimes – most times actually – the offending dampness results from moisture produced inside the house, which is struggling to get out.

This survey arose because the house was suffering from damp patches on the chimneybreast, and the client, who was a most helpful and experienced civil engineer, automatically assumed the problem was being caused by a fault with either the flashings, flaunching or pointing on the chimneystack.  This was the case even though he had had all of these items inspected and ‘repaired’ on previous occasions.

So, given that he’d had trusted builder/roofers attend to the problem beforehand, I’m not quite sure what he expected me to discover, especially as I had no intentions of going onto his frosty roof. However, what I did discover came as a complete surprise to him.  It was something he’d never even considered….

This delightful house, approximately two hundred years old, was probably coping perfectly well with its environment. Then, approximately thirty years ago, someone decided to intall a new floor.  They did everything as they should do, probably even put a damp proofing membrane beneath the new screed; they certainly installed an asphalt coating over it.

Result, all the moisture in the old floor that had been happliy evaporating, and then disappearing into the wild blue yonder, now had nowhere to go. Except that is for into the base of the walls, where it rose steadily upwards.

To counteract this, an injection dpc was attempted - in 600mm thick, rubble-filled walls.  They may as well have lit Joss sticks to tempt the damp away.  The current condition of the walls is displayed in the photo below.

Now, as it isn't going to be possible to resurrect the original flagged floor, it will be necessary to apply cavity membranes to the base of all of the internal walls.  Not my idea of how old houses should be treated, but it's better than trying to live with permanently damp walls. Moral, dont mix modern practices with old properties - they don't usually work.

Just as a matter of interest, this house had been locked up over the summer and it seems to have been a meeting point for the local fly population.  They must have been having some sort of party on the window cills, and this is what happens to them when they've had a little too much to drink!

A strong stomach was required to inspect the window reveals

A few years ago, this client had converted their basement into a kitchen, which is a situation I often see.  Unfortunately, the original work seemed to be going pear-shaped due to dampness in the form of stains, mould growth and excessive mildew in cupboards etc.  Rather than go back to the original people, the client decided to ask another contractor for some advice, which is rather like asking a donkey if it wants another strawberry.

Said contractor did his survey and pronounced the room 'Damp'.  He didn't explain why it was damp, but did commiserate with them in the knowledge that several thousand pounds worth of work was needed; to cure rising dampness and rotten timbers in the ceiling (how these timbers had rotted when they weren't in contact with any masonry or free water was never quite explained).

He proceeded to rip out the old and install the new; however, the client seems to have become suspicious of all the extra tasks he found necessary - the bill was up around the 7k mark by this time!

Rather than prolong their agony, the clients bearded the chap in his lair, well in their kitchen actually, and the upshot was they had a fall-out.  Not quite nuclear but nevertheless enough for him to storm off in high dudgeon, with the threat that, unless they gave him their very last red corpuscle, his work would no longer be guaranteed (he needs to do a little reading on contract law before he issues statments like that)!

Anyhow, now in a state of despair and utter confusion, the clients asked for an independent. Lo and behold, the most obvious, common and ubiquitous source of moisture in situations such as this - condensation - had never even been mentioned.  Seven unnecessary K later and I have to break the news to them - gently.

At least the contractor was 'Permaguard' approved.  So that's all right then...

We never did get to the bottom of this one.  The floor had obviously been flooded quite badly but there were no obvious source for the water, as you can see from the report below.  Behind the rear wall of the flat was an extensive void, and at first I though that this had maybe flooded due to a drainage problem in the adjacent road.  Eventually though, this became less likely. 

A flood from the flat above was also ruled out and condensation was definitely not the cause.  The NHBC, insurance assessors, Uncle Tom Cobbly and all eventually became involved, and of course no one would admit any liability. The client eventually took it on the chin, paid for the repairs and sold the property. 

I learned later that there had been considerable confusion as to the exact time the fault had been reported by the letting agent; and it turned out that the flat may have been empty for some considerable time after the last tenant left before the letting agent visited the house to do an inventory. 

Little Weed (you'll have to be old enough to remember Bill and Ben) told me that the  last tenant had flooded the house, not said anything, and just left.  I think Little Weed may have been right!

The problems in this property were so bad the owner couldn't believe he didn't have severe structural problems.  A look at the way the property was set up and how it was used by the tenants certainly threw doubt on this presumption...
 

This unusual phenomenon is caused by patches of salt contamination in the plaster.  The salts are hygroscopic and absorb moisture from the atmosphere when the relative humidity is high.  Once the humidity returns to normal levels, the patches disappear.  This makes it difficult to spot unless the conditions are right. 

You can only make so many holes in the wall with your moisture meter before the lady of the house asks you to leave!

This survey was carried out on a brick terraced property that already had  damp proof courses installed, but the building society surveyor still found damp!

A survey in which the chartered surveyor had wrongly diagnosed the condensation and penetrating dampness as 'rising damp' and had unfortunatey missed the dry-rot under the dining room floor 

All hands to the pumps with this one. Imagine discovering a waterfall cascading down your wall, four hours before you're due to catch a 'plane! 

A cautionary tale: Don't just brick up fireplaces and then expect them to sit quietly and behave themselves. Lack of maintenance will cost this lady thousands!