Damp Course Explained: A Comprehensive Overview

Damp Course Explained: A Comprehensive Overview

3rd July, 2025

Water is a wonderful substance, we are largely made of it and we can’t live without it! But water can be destructive, too, especially when it enters our homes uninvited! While the first thing that probably came to mind at that thought was a leaky roof, very often the unwelcome presence of water doesn’t come from the sky down, but from the ground up! In this case, we are referring to a very common problem found in homes and businesses across London that is all too often ignored or neglected, the slow, insidious scourge of the rising damp!

Rising damp refers to a condition in which the walls of a building are insufficiently protected from the wet ground they rest on, allowing water to be drawn upwards into the walls! It may seem surprising, but a great many building materials are more porous than you might think, wood and even brick and mortar have tiny crevices running through them that can suck up water via capillary action, just like a sponge sitting in a puddle!

Fortunately, there is a way to stop rising damp in its tracks, the presence of something called a ‘damp proof course’. This simple solution forms a physical waterproof barrier between the ground and the walls, preventing rising damp from permeating upwards through porous materials. The damp proof course is a protective barrier installed between the wood or brickwork, and is now a common feature in modern construction that stops rising damp from ever happening.

The damp proof course is essential to preventing damage to internal walls, coverings, and finishes from the ravages caused by the rising damp. Unwelcome moisture in a building can bring a variety of problems, it deteriorates paint and plaster causing it to peel and bubble, causes rot in wood, and makes a home for hazardous black spot mould to thrive. Rising damp that goes untreated is not only unsightly, it can result in untold damage to a property, as well as cause health risks to those in residence.

Today most properties on the market are equipped with a damp proof course during their initial construction, but the materials they are made from have the possibility of failing over the years. Replacing a physical damp proof course can be difficult considering they are built into the walls! If this does happen, the next step is to have a chemical-based damp proof course installed, a waterproof cream or gel that can be injected directly into porous building materials to fill up those tiny crevices and stop the water from entering.

If your property is suffering from a case of rising damp please call us, it’s important to take action swiftly! Ring up London Damp Surveys at 0207 305 5997 and schedule our technicians to come out to make a thorough survey. Our highly experienced surveyors use cutting-edge equipment to perform our damp inspections, ensuring that they are done to the highest standards to help you stop the rising damp!

Damp Survey Costs

Transparent pricing with no hidden fees for our independent, unbiased surveys.

Level 1

Level 1

£199 + VAT

What’s included:

  • Inspection of walls
  • Inspection of floors
  • Inspection of ceilings
  • Leak inspection of drains and plumbing
  • Damp information and prevention guide
Level 2

Level 2

£299 + VAT

What’s included:

  • Everything in Level 1
  • Dry rot inspection
  • Wet rot inspection
  • Woodworm inspection
  • Damp information and prevention guide

 Survey Add Ons

Add On 1

£299 + VAT
Lab Analysis Of Plaster

Laboratory analysis Of plaster identifies hygroscopic salts such as chlorides and nitrates. which indicate whether damp is caused by rising groundwater or by plumbing leaks, This testing removes guesswork, allowing the exact source of moisture to be identified so the correct treatment is applied rather than carrying out unnecessary damp-proofing work.

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Add On 2

£299 + VAT
Mould Lab Swab Testing, qPCR on DNA

qPCR DNA mould testing detects microscopic mould spores that are invisible during a normal inspection and van remain hidden behind walls, floors. or inside building rkaterials. It identifies the exact mould species present and the contamination level, allowing hidden mould problems to be confirrned and properly treated before they affect the property or occupants’ health.

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Qualifications: All our surveyors are PCA and CSRT qualified for remedial treatments and also CSSW qualified for structural waterproofing.
Next day report: You will receive the report within 24 hours of the inspection taking place.

These are the tools we use

A damp meter

A damp meter

A damp meter is a diagnostic tool used to detect and measure moisture levels within building materials such as plaster, brick, timber, and concrete.

Borescope camera

Borescope camera

borescope camera is a small inspection camera attached to a flexible semi-rigid cable that allows you to see inside areas that are otherwise inaccessible.

Inspection Drone

Inspection Drone

A drone is a remotely operated aerial device equipped with a camera that allows visual inspection from above without the need for scaffolding or ladder.

Air Humidity Sensor

Air Humidity Sensor

Air humidity sensor measures the amount of moisture present in the air, expressed as relative humidity (RH) in percentage. It helps determine whether indoor conditions are contributing to condensation, mould growth, or damp-related issues.

Thermal Imaging Camera

Thermal Imaging Camera

A thermal imaging camera detects temperature differences on surfaces by using infrared technology to produce a heat map image. In damp investigations, it helps identify cold spots, moisture intrusion, insulation defects, thermal bridging and leaks.

Air Flow Ventilation Detector

Air Flow Ventilation Detector

An air flow ventilation detector measures the movement and volume of air passing through vents, extractor fans, and air bricks. It confirms whether ventilation systems are working properly and achieving adequate air changes within a room. Poor airflow leads to trapped moisture, high humidity, condensation on cold surfaces, and ultimately mould growth.

Mould Swab Test Kit

Mould Swab Test Kit

A mould swab test is carried out to confirm the presence of hidden mould growth and identify the specific species involved. Surface mould is not always visible, especially behind furniture, inside cavities, or within ventilation systems. Laboratory analysis of a swab sample determines whether active mould spores are present and what type they are, which helps assess potential health risks and decide the correct remediation approach rather than relying on visual assumption alone.

Plaster Salt Analysis Lab

Plaster Salt Analysis Lab

Laboratory analysis of plaster is used to identify the type of salts present within the material, typically chlorides and nitrates. The presence and concentration of these salts help determine whether the moisture source is consistent with rising damp, ground contamination, or another forms [sic] of water ingress. such as mains water leak, This removes guesswork and prevents misdiagnosis, ensuring the correct remedial treatment is specified rather than applying unnecessary or ineffective solutions.