damp and how to cure it using conservation methods


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See notes on DRY ROT
See notes on WOODWORM
See notes on FRENCH DRAINS
Below ground DELTA LATH

Dealing with damp 
using conservation methods


Damp is probably the first thing people think of when it comes to old houses, and indeed it is likely to be a problem you may be suffering from on a daily basis and why your reading this page now......   There is nothing fundamentally wrong with old buildings its more often a matter of what we have done with them over the last 70 years, using incompatible materials or change of use.  It's not that old buildings did not suffer from damp in the past, they did, but then too they had methods for dealing with it, some of which are still appropriate today.  People tend to view damp problems more from the aesthetics perspective, the peeling paint, the black mould, but this is only the tip of the iceberg, the big issues are comfort and health, moulds are a huge health issue read about it here Moulds & Health in the Indoor Environment-Moulds -    -  Toxic moulds health effects and law-suits on the rise..

The good news is that most damp issues can be solved but there are many causes, and correct diagnosis is critical if the correct works are to be specified. You're not going to solve a penetrating damp problem by treating for rising damp.  Its also very important to distinguish between what is causing the damp and the symptoms of damp, IE, peeling paint can be a symptom of damp, like your own health issues, you need to deal with the causes not the symptoms.  Scraping off the paint, applying a water proofer and repainting has not cured the damp, just the immediate and most visible of the symptoms.

Be wary of the "EXPERT damp Surveyor" armed with a damp meter - he probably has not read the surveyors CODE OF PRACTICE FOR THE CONTROL OF CONDENSATION IN BUILDINGS, BS 5250: 2011, and CODE OF PRACTICE FOR DIAGNOSIS OF RISING DAMP IN WALLS BS 6576:2005 +A1:2012  - selected extracts..... "..accurate measurements of the moisture content of brick or mortar cannot be obtained by the use of electrical moisture meters because the presence of salts increases the electrical conductance of the water, giving falsely high readings". ........... Surface moisture monitoring alone cannot give proof of rising damp". ...... - That does not mean you don't have rising damp, but don't let them sell you a chemical injection.  See what the consumer magazine WHICH had to say about free damp surveys where 2/3 of the surveyors recommended unnecessary treatment.

Why not ask the experts by using our consultation advisory service We will visit your site in person and give you the benefit of our 40 years in the conservation business, its not free advice but its good advice..

SOME OF THE  CAUSES OF DAMPNESS AND (important distinction)


Rising damp in walls and floors
Penetrating damp through external walls
Ricocheting from adjoining surfaces
Internal and interstitial condensation
High humidity levels internally
Poorly installed or inappropriate insulation
Modern acrylic and oil based paints
External cement render
Internal cement plaster
Pointing, in cement or poorly applied & finished lime pointing
Gypsum plasters
Cement floors
DPM's, damp proof membranes, usually move the problem from one area to another
DPC's, chemical damp proof courses prevent the wall breathing and cause other problems
Interference with, or silted original drainage
Absorbent salts from newer introduced materials such as portland cement
Salts, from original sands and aggregates
Contamination from animal waste
Sulphates from chimney smoke
Introduction of chemicals into the fabric or surface of the building
Ground levels outside higher than inside
Hydrostatic pressure from high ground near by
Broken guttering or missing downpipes
Blocked or damaged waste pipes and drainage
Vegetation growing near the wall
Trees creating shade and moist air near a wall
Driving rain and wind
Micro weather patterns
Lack of ventilation - double glazing, no vents
Blocked chimneys - fireplace blocked up, no vents
Furniture against walls creating cold, damp areas
leaking internal pipes, water, heating, drainage pipes
Impermeable floor coverings such as lino or impervious fibers in carpets and coverings
External masonry structures such as steps, gate posts and adjoining buildings
Hidden roof and flashing leaks over walls, tiles, slates, gulleys
Incorrectly installed or faulty roof felt

Its quite critical in old buildings, when dealing with damp, to properly determine the source of the moisture in order to correctly fix the issues, you must take the whole building environment into consideration. As tempting as it will be, its rarely just a simple one issue problem, one that a quick fix and a bit of waterproof cement will solve. OldBuilders Company has extensive experience in dealing with damp and the correct procedures required to help solve your problems. Solutions and materials that may well be quite suitable for modern cavity walled buildings are rarely appropriate when applied to the very different fabric found in old solid walled structures. Please consider using our  CONSULTATION  service,

If you walk into a pizza restaurant and tell them your hungry, chances are they will recommend a pizza. Funnily enough this happens in the building industry too, so don't be surprised when you get one of those free surveys from a damp proofing company that sells chemical wall injections to recommend...... a chemical wall injection.

Regrettably, in the damp industry, as in woodworm treatment, we find that many of the building industry's representatives (outside the conservation professionals at least), I.E. the regular builders, architects, surveyors and engineers have largely left the diagnoses and treatment of damp to the remedial industry, who certainly have a direct conflict of interest in that they are usually asked to both diagnose and treat the problem. It could also be said that most would have little interest, knowledge or concern for the preservation of original historic fabric of a building. The over reliance on damp meter is something to be especially wary of, the standard damp meter measures conductivity between the moisture meters poles, both surface moisture and salts are conductive, surface moisture is often caused by condensation, this and the presence of salts and contaminates will give rise to a false diagnosis of rising damp.

With misdiagnosis, and the subsequent inappropriate use of chemical treatment of masonry, water proofers etc.,  causing more problems than they solve, will result in failure of the system along with the destruction of original fabric of the building.

OldBuilders does not sell any products, the diagnosis and solutions we follow are those that have been recommended by the conservation industry after many years of research and observations, they have no interest in selling products either. The key to curing or improving damp in old buildings is to reintroduce the correct functionality of the building fabric by using compatible and breathable materials.

If you have a damp problem, please call us to discuss what we can do for you, please also consider using our CONSULTATION service, we don't offer you a free survey, but we do offer you our 40 years of experience in dealing with these problems..