If plaster is blowing, cracking, or breaking away near corners in your Ashbourne home — while the rest of the wall appears sound — this often causes confusion. Many homeowners assume damp must be rising through the wall, but corner-only failure is rarely caused by rising or penetrating damp.
In most cases, plaster failure at corners is driven by thermal bridging and trapped condensation, not water ingress. Corners are typically the coldest areas of a room, making them prime locations for moisture to settle unseen.
At Weather Wise Solutions — a family-run damp and ventilation specialist — this is a common issue we see in both older and modern properties across Derbyshire.
🧱 Why Plaster Fails at Corners First
1️⃣ Thermal Bridging at External Corners
Corners often involve two external walls meeting. This creates a thermal bridge where heat escapes faster, leaving the surface colder than surrounding wall areas.
Cold surfaces attract moisture from the air — even when walls don’t look visibly wet.
2️⃣ Condensation Trapped Behind Plaster
Moisture can repeatedly condense at cold corners, soak into the plaster, and evaporate again. Over time, this cycling weakens the plaster bond, causing it to blow or crumble.
3️⃣ No Obvious Damp Staining
Because condensation often forms overnight and dries during the day, there may be no visible damp marks, only plaster deterioration. This is why the issue is frequently misdiagnosed.
4️⃣ Restricted Airflow at Corners
Corners are often poorly ventilated areas — particularly behind furniture or in unused spaces. Reduced airflow allows cold surfaces to remain damp for longer.
5️⃣ Incompatible Plaster Materials
Standard gypsum plaster performs poorly in areas affected by condensation. Once it absorbs moisture repeatedly, it loses strength and begins to fail.
🔍 How We Diagnose Blown Plaster in Ashbourne
Rather than relying on a single damp meter reading, we assess why the plaster is failing, including:
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Identifying thermal bridges at corners
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Checking surface temperatures
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Assessing humidity and condensation risk
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Reviewing airflow and ventilation provision
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Ruling out penetrating or rising damp
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Checking for bridging or detailing issues
This ensures condensation-led plaster failure isn’t mistaken for structural damp.
🛠️ How Corner Plaster Failure Is Properly Resolved
Depending on findings, effective solutions may include:
✔ Reducing Thermal Bridging
Improving insulation continuity to raise surface temperatures at corners.
✔ Improving Ventilation
Removing humid air before it can condense on cold surfaces.
✔ Correct Plaster Specification
Using breathable or salt-resistant plaster systems where moisture exposure is unavoidable.
✔ Preventing Repeat Failure
Ensuring conditions are stabilised before redecorating or replastering.
Where materials or systems are required, we work with trusted suppliers including:
🔗 PAM Ties – https://www.pamties.co.uk/
🔗 Wykamol Group – https://wykamol.com/
All advice aligns with guidance from:
🔗 Federation of Damp – https://federationofdamp.co.uk/
🔗 Damp Proofing Association – https://www.dampproofingassociation.co.uk/
For independent reassurance, you can also view our profiles on:
🔗 TrustATrader – https://www.trustatrader.com/traders/weather-wise-solutions-limited-damp-surveyor-newcastle-under-lyme
🔗 Checkatrade – https://www.checkatrade.com/trades/weatherwisesolutionslimited
Blown plaster at corners is usually a temperature and airflow issue —
not a leak.
Correct diagnosis prevents unnecessary damp proofing.
📍 Book a free survey:
https://weatherwiseuk.co.uk/pages/contact