You see damp stains or mold after rain and want to detect cavity wall leakage. We check the cavity wall, facade, inner leaf, and outer wall. We examine insulation, weep holes, pointing, and lead flashing.
With smart leak detection, we trace cavity wall leaks using thermography, thermal imaging cameras, endoscopy, dye testing, moisture measurement, and tracer gas. This allows us to distinguish between penetrating damp, condensation, and thermal bridges, and locate the source.
We are Ultrices Leak Detection and we help you quickly with a clear plan. Google reviews 5 out of 5. Read our reviews on detecting cavity wall leaks.
Table of contents
Detecting cavity wall leaks explained
Detecting cavity wall leaks revolves around specifically identifying moisture sources entering the cavity via the exterior facade or internal connections. The cavity wall consists of an inner leaf and an outer leaf with an air gap that drains rainwater and limits thermal bridges. If water bypasses the cavity bridge due to contamination, saturated insulation, or defects, you get damp spots, mold, peeling plaster, and energy loss. We investigate the entire moisture chain according to building physics principles such as capillary action, condensation, and rain penetration, in line with NEN 2778 and knowledge from TNO and TU Delft. In this way, we provide evidence, causal links, and a plan of action that is clear and acceptable to insurers. With Ultrices leak detection, you choose to detect cavity wall leaks without demolition work, with accurate measurement data and an expert report that stands up to scrutiny.
Causes and signs you recognize quickly
- Cavity contaminationConstruction debris, mortar protrusions, and clogged open weep holes no longer drain water, causing water bridges to form towards the inner leaf.
- Damaged or saturated insulation materialMineral wool, EPS beads, or UF foam can retain water and transport water to the inner leaf.
- Defects around window frames and lintels: Faulty lead flashing, cracks in sealant joints, and connection errors cause water ingress and leakage around window frames.
- Aged mortar and brickworkFrost damage, hairline cracks, and high water absorption according to the Karsten RILEM pipe cause penetration through the facade during wind and rain.
- Corrosion or incorrectly placed cavity wall tiesBridging and cracking create pathways along which moisture moves.
- Damp spots and rings: Irregular stains on interior walls, especially after rain and on west-facing walls.
- Peeling paint or mold: Damp areas with musty odor and peeling finish around skirting boards and reveals.
- Cold zones and drafts: Thermal anomalies and comfort complaints due to wet insulation and thermal bridges.
- Varying intensity: An increase after showers or strong winds indicates rain penetration and wall penetration rather than a pipe leak.
How we detect cavity wall leaks without hacking or breaking.
We combine structural inspection with instrumental measurements and simulation. We use thermography with FLIR cameras to visualize thermal patterns, endoscopy with Ridgid borescopes to look into the cavity via micro-drilling, moisture measurement with Protimeter and Tramex for calibration between surface and depth, a smoke test and dye test with fluorescein to follow water paths, and a water test on window frames in accordance with NEN EN 1027. The Karsten RILEM tube measures local water absorption of masonry. With differential pressure measurements via blower door, we simulate wind pressure so that rain impact is realistically simulated. We record every measurement result in a photolog with measured values and a timeline. If you would like to delve into our methodology in advance, please read In-depth leak detection in the cavity wall.
Techniques and tools with a scientific basis
- Thermography: Infrared analysis reveals cold zones caused by wet insulation and hidden moisture migration, including heat leaks and thermal bridges.
- Endoscopy: Direct view of cavity contamination, wet insulation, cavity anchors, and open weep holes with minimal intervention.
- Moisture and salt diagnosis: Hygrometry, dielectric measurements, and conductivity to distinguish between rainwater and other moisture.
- Karsten RILEM test: Quantifies water absorption of brick and mortar for well-founded facade advice such as hydrophobing or joint repair.
- Waterproof and dye: Reproduces leakage and marks exact entry points around the frame, expansion joint, and lead flashing.
For additional facade issues and the connection to the exterior shell, read on via Targeted approach for facade leakage or delve into causes and solutions via More about moisture in the cavity wall.
Step-by-step plan from intake to expert report
- Intake and hypothesis formation: Telephone preliminary analysis with photos and complaint patterns linked to rain radar history and facade orientation.
- Non-destructive baseline measurement: Thermography, moisture profiling and inspection of open weep holes, lead flashing, sealant joints and expansion joints.
- Targeted provocation: Water test, smoke, or dye under controlled pressure conditions to activate and record the leak recipe.
- Diagnosis and advice: Mapping cause and effect with repair advice for pointing, lead, frame movement, cavity cleaning, or insulation repair.
- Report and aftercare: Expert report within three days with measurement data, images, and conclusions suitable for insurance, plus guidance during recovery.
Leak detection process request
Results, costs and insurance
With Ultrices leak detection, you benefit from over fifteen years of experience, VCA VOL and NEN 3140 certified personnel, professional detection equipment, and nationwide coverage. We are on-site quickly and achieve an exceptionally high success rate. No solution means no payment thanks to our no-cure, no-pay policy. We provide an Expert Report that insurers accept, including a clear cause and repair advice, with a guarantee of coverage where applicable. Do you want quick clarity and cost control, Request a no-obligation cavity wall leak quote within 24 hours.Call or WhatsApp 085 2505 217 or email info@Ultriceslekdetectie.nl for immediate assistance. Our 5 out of 5 Google reviews, fast response times, and focus on no demolition work ensure that you have dry and healthy walls again in a short time.
Frequently asked questions
What are the clearest signs of a cavity wall leak and what do you do first?
Watch out for damp patches around window frames, mold growth, peeling plaster, salt efflorescence on brick, and a musty odor. If you see cold zones or if walls feel chilly, cavity insulation may have become wet, causing the insulation value to drop. This often occurs especially after wind and rain, which is consistent with penetrating damp and a failing damp-proof course or open weep holes.
Take photos with the date and note when the spots appear. Rule out internal sources such as a leaking radiator. Then call us. We are available nationwide, arrive on-site within 1 hour in case of emergency, and work without any demolition or breaking. Want to know more about odor complaints and causes in the cavity wall? Read more via musty smell due to cavity wall moisture.
How do you detect cavity wall leaks without demolition?
We combine non-destructive techniques to provide conclusive evidence. Using thermography, we capture temperature differences that indicate wet insulation or thermal bridges. Moisture measurements in interior walls reveal the migration pattern of water. Via endoscopy through existing open weep holes, we inspect the cavity for contamination, missing damp-proof courses, and leaky lead flashing. We measure air leaks using a smoke test and air pressure, and a targeted spray test simulates wind-driven rain according to building physics principles also described by TNO and TU Delft.
Our approach is systematic and reproducible. We correlate measurement data with KNMI rainfall events and document everything in an expert report within 3 days. Thanks to professional equipment and more than 15 years of experience, we achieve a 99 percent success rate. No solution means no payment; it is entirely no cure, no pay. If you want to know exactly how we work without demolition, take a look. cavity wall leak detection without chiseling.
My facade only leaks when it rains. Is this coming from the cavity, and what should I do now?
Yes, wind-driven rain often plays a major role. Water penetrates the cavity through porous mortar joints, hairline cracks, poorly adjusted or clogged weep holes, or a broken damp-proof course. During strong winds, external air pressure builds up, and moisture is drawn deeper inside by capillary action. Wet cavity wall insulation exacerbates this by retaining water and causing heat loss.
We conduct targeted testing during or shortly after rain. With a controlled spray test on sub-areas, supplemented by thermography, a smoke test, and endoscopy, we pinpoint exactly where the problem lies. This prevents guesswork and unnecessary costs. Our VCA VOL and NEN 3140 certified specialists at Ultrices Leak Detection offer emergency service and are on-site quickly in the event of acute water damage. You receive clear repair advice and a guarantee of coverage for the cause.
How much does it cost to detect a cavity wall leak, and is this covered by your insurance?
The price depends on the type of property, the height and accessibility of the facade, and the number of test methods required. You will receive a free fixed-price quote within 24 hours so you know exactly where you stand. We work nationwide, without disruptive demolition work, and on a no-cure-no-pay basis. After the inspection, we deliver a complete expert report within 3 days, including photos, measurements, and conclusions.
Insurers often reimburse consequential damage from leakage and sometimes also leak detection costs, depending on your policy. We work with insurers daily and help you with the substantiation. If you want to check what is covered, view cavity wall leakage covered by insuranceOur 5 out of 5 star ratings and coverage guarantee provide extra security for your claim.