What is Damp Proofing?

When Dean and I started South East Timber and Damp Limited in 2005, I had absolutely no clue about damp or damp proofing. I’d spent my career in the travel industry, working for tour operators and international airlines, about as far from building problems as you could get!

Twenty years on, and whilst I still leave the technical wizardry to my husband Dean (our certified surveyor with over 30 years’ experience since leaving school at 16), I’ve learnt something crucial: “damp proofing isn’t just about injecting cream into walls anymore”.

What I have discovered is that damp proofing can be deceptively simple – or frustratingly complex. The key lies in understanding what you’re actually dealing with, especially here in Kent and South East London, where our unique climate presents particular challenges.

The Evolution of Damp Proofing

The term “damp proofing” is, frankly, a bit outdated. In the old days, it simply meant injecting a chemical cream to stop rising damp, job done. Today’s reality is far more sophisticated.

Modern damp proofing is really an umbrella term covering the comprehensive approach to moisture control in buildings. It’s about diagnosing, treating, and preventing all forms of unwanted moisture that can damage your property and, crucially, affect your health.

According to the Property Care Association (PCA), damp proofing describes the measures of protection against damp within the structure, masonry, or fabric of a building, widely used to describe the control of many forms of dampness and moisture (Property Care Association, 2024).

Start By Identifying the Source of Damp (This Is Absolutely Critical!)

In my twenty years of watching Dean work, the biggest mistake I see non-experts make is not establishing where the moisture is coming from. I’ve seen houses ripped apart at enormous cost to “damp-proof” them, only for the problem to return because nobody fixed the blocked gutters that were causing the issue in the first place!

Common Sources of Moisture in Kent Homes

• Rising damp: Moisture drawn up through masonry via capillary action
• Penetrating damp: Water entering through defective walls, roofs, or windows
• Condensation: Often the most common cause, especially in modern sealed buildings
• Plumbing leaks: From radiators, pipes, or appliances
• Structural issues: Cracked renders, broken tiles, defective pointing
• External factors: High ground levels, blocked drains, damaged rainwater goods
• Ventilation problems: Inadequate air circulation leading to moisture build-up

Climate Change Impact in Our Region

Kent is predicted to experience some of the most severe climate change impacts in the UK. According to the Kent Downs National Landscape Partnership, our region faces:

• Hotter, drier summers: Average summer temperatures rising by 2-3°C by 2040, potentially 5-6°C by 2080
• Warmer, wetter winters: 10-20% more precipitation by 2040, rising to 20-30% by 2080
• More intense rainfall events: Up to 25% increase in southeast England
• Rising sea levels: 30-80cm predicted by 2100

Drought in the summer months has long been an issue for South-East England. Now exacerbated by climate change, Kent has less predictable but generally drier summers, and wetter winters prone to flood events (State of Nature in Kent, 2021).

What This Means for Your Property

These changing weather patterns create a perfect storm for damp problems:

• Extreme weather cycles: Intense dry periods followed by heavy rainfall stress building materials
• Flooding risk: More frequent winter flooding affects foundations and lower walls
• Ground movement: Clay soils expand and contract more dramatically, affecting damp-proof courses
• Increased humidity: More moisture in the air during wet periods

“The flooding of rivers and tributaries is becoming more common… There has been an increase in extreme weather events” (Kent Downs National Landscape climate observations)

Technical Approaches to Damp Control

Diagnostic Methods

Professional damp diagnosis now involves:

• Moisture meters: Electronic detection of water content in materials
• Thermal imaging: Identifying cold spots and moisture patterns
• Hygrometers: Measuring relative humidity levels
• Salt analysis: Detecting hygroscopic salts that attract moisture
• Carbide testing: Accurate moisture content measurement

Treatment Solutions

Rising Damp Control:

• Chemical damp-proof course injection
• Physical damp proof course installation
• Electro-osmotic systems
• External waterproofing membranes

Penetrating Damp Solutions:

• External wall treatments and sealers
• Structural repairs (repointing, render repairs)
• Cavity wall remediation
• Roof and gutter maintenance

Condensation Control:

• Mechanical ventilation systems
• Positive input ventilation (PIV)
• Heat recovery ventilation
• Improved insulation and heating efficiency

The Most Important Lesson I’ve Learned

After two decades in this industry, here’s what I want every homeowner to understand: get an expert to assess your problem first.

I cannot stress this enough. You might end up paying for two sets of treatments if you get it wrong the first time. We’ve seen it happen countless times – someone attempts a DIY solution or hires an unqualified contractor, and they end up spending double to fix both the original problem and the botched repair.

So, before you ask “How can I damp-proof my walls?” or “What does damp proofing involve?”, stop and let us first establish precisely what is causing the moisture.

Contact the team

If you’re experiencing damp problems in Kent or South East London, I can arrange for you to speak with Dean. He can talk through what you’re experiencing, and for a fee (see our surveys page), we’ll come and properly diagnose the issue.

Remember: In our changing climate, damp problems are only going to become more common. Early intervention saves money, protects your health, and preserves your property value.

Thank you for reading – Annabelle (The Damp Lady – but definitely not the expert!)