Penetrating Damp Surveys

Independent damp investigations to pinpoint water ingress and provide clear, practical repair advice.

Ceiling with water damage and stains near the corner of a room.

Typical signs of penetrating damp include:

  • Localised brown/yellow stains after rainfall

  • Flaking or blistering paintwork

  • Damp patches around windows, doors or ceiling junctions

  • Salt deposits or crumbling plaster

  • Drips or leaks in heavy wind-driven rain

Signs & Symptoms

What Causes Penetrating Damp

Common causes we diagnose:

Close-up of a rooftop with weathered, mossy shingles and a metal pipe or cable attached along the edge.

Defective roof coverings and flashings

Plants growing between moss-covered roof tiles on a sloped roof, with a small black structure and trees in the background.

Blocked or undersized gutters and downpipes

Close-up of a window frame with a small twig resting on the windowsill, showing weathered paint and dirt.

Cracked render or missing pointing

Failed window sealants and cavity trays

Poorly detailed parapets or coping stones

Service penetrations allowing water tracking

How We Investigate

Diagnosing penetrating damp is a process of elimination.
We begin with a non-destructive survey and provide a clear report before any further investigations are carried out.

Stage 1 - Initial Damp Survey

Step 1 – Understand the Problem

We start by gathering background information:

  • When and where the damp appears

  • Weather conditions that trigger it

  • Any previous repair attempts

This helps us target our inspection efficiently.

Depending on the findings, we may suggest one or more of the following:

  • Tracer dye or controlled water testing to track hidden leaks

  • Small, targeted opening-ups to inspect concealed details such as cavity trays or flashings

  • Calcium-carbide (Speedy) moisture tests for precise readings

  • Salt analysis tests to identify hygroscopic salts in plaster or masonry

  • Drone inspections for inaccessible roofs or chimneys

Stage 2 ensures we identify the true root cause by ruling out remaining possibilities step by step.

Step 2 – Initial Non-Destructive Inspection

We carry out a detailed internal and external inspection using:

  • Moisture readings to track damp movement

  • Visual checks of roofs, walls, windows and rainwater goods

  • Thermal imaging where conditions allow

This first visit causes no damage — we use only existing access points such as loft hatches and ladders.

Stage 2 - Optional Further Investigations

Step 3 – Report & Recommendations

We issue a clear, independent PDF report with:

  • Photographs and moisture maps

  • Likely causes of the damp problem

  • Practical, prioritised repair advice

  • Recommended next steps if further testing is needed

This report gives you the information you need to take action — whether that’s instructing repairs or authorising further investigation.

Damp meter on damp affected wall

Concise PDF report with photos and recommendations

  1. Moisture maps and prioritised remedial advice

  2. Optional follow-up verification visit

What You Receive

Clear, Transparent Pricing

We believe in complete transparency.
You’ll know exactly what you’re paying for, with no hidden costs and no sales agenda.

Stage 1 – Initial Non-Destructive Survey & Report

From £395 (no VAT)

  • On-site inspection

  • Moisture mapping and photographic evidence

  • Independent PDF report with findings and recommendations

The Stage 1 report gives you clear next steps — whether that’s instructing repairs or moving on to Stage 2 testing.

Stage 2 – Optional Further Investigations

Quoted separately, only if required.

  • Targeted testing such as tracer dyes, controlled water tests, or salt analysis

  • Small, controlled opening-ups if necessary

  • Drone inspections for difficult-to-reach areas

You’ll always receive a Stage 1 report first before authorising any Stage 2 works.

Pricing

Why Clients Trust Durndell Damp Surveys

With over 25 years of experience diagnosing damp issues in homes, historic buildings, and complex commercial properties, we bring unrivalled expertise to every survey.
As MRICS Chartered Building Surveyors, we follow RICS standards and always provide independent, evidence-based advice — never driven by sales targets or unnecessary treatments.

Why Choose Us

Close-up of a Timex quartz alarm clock showing 1:00.

25 Years of Experience

We’ve spent decades investigating damp and water ingress problems across thousands of buildings — from modern homes to listed heritage properties and specialist environments like hospitals, schools, and laboratories.

This depth of experience means we quickly recognise patterns and causes that less experienced inspectors might miss.

Statue of Lady Justice holding scales in her right hand and a sword in her left hand, with a blindfold over her eyes.

Independent & Impartial Advice

Unlike contractors who offer “free surveys” in order to sell you chemical treatments or tanking, we don’t carry out remedial works.
Our role is purely diagnostic — giving you clear, honest advice on the true cause of the problem.

This protects you from unnecessary costs and ensures you only pay for what’s genuinely needed.

RICS logo with a lion's head in a circle and the words "Regulated by RICS"

Regulated by RICS (Royal Institution of Chartered Surveyors)

As MRICS Chartered Building Surveyors, we are regulated by RICS, which guarantees that our inspections, reports, and advice meet strict professional and ethical standards.

Our surveys are also backed by professional indemnity and public liability insurance, providing complete peace of mind.

You’re protected by the highest level of professionalism and accountability in the industry.

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Clear, Practical Reports You Can Act On

We provide reports that are easy to understand and actionable. Each report includes:

  • Photographs and moisture maps

  • A root cause diagnosis, not just symptoms

  • Prioritised remedial recommendations

  • Guidance your contractor can implement confidently

Whether you’re a homeowner or managing a large estate, our reports help you fix or manage the problem properly.

Large lawn with trees and a historic red brick building with chimneys under a partly cloudy blue sky.

Local Knowledge

Based in Milton Keynes, we understand the typical building styles and materials found across the local area, from historic stone cottages to modern housing developments.

Areas We Cover:

We are based in Milton Keynes and typically cover properties within a 30–45 minute drive, including Buckingham, Towcester, Northampton, Bedford, Aylesbury, Leighton Buzzard, and surrounding towns and villages.

If you’re unsure whether we cover your location, please get in touch — we’ll be happy to advise.

Map of Northamptonshire and surrounding areas in England, with a shaded circular zone highlighting the region around Northampton.

Request a Penetrating Damp Survey Today

If you’re concerned about damp patches, leaks, or water ingress, don’t leave it until it causes serious structural damage.

Our independent, RICS-regulated surveys provide a clear diagnosis and practical advice you can trust. With over 25 years of experience, we’ll help you identify the true cause of penetrating damp and guide you through the next steps with confidence.