When Is a New DPC Actually Necessary?
In Blackpool and surrounding coastal towns, many older properties suffer from what appears to be rising damp. However, in some cases, the existing DPC is working just fine, and the real issue lies in trapped salts and bridging plaster.
At Weather Wise, we often get called in to quote for a full new DPC, but after inspection, we find the root cause is actually plaster contamination or poor ventilation.
Rising Damp vs Salt Contamination
Here’s how to tell the difference:
| Rising Damp | Salt-Contaminated Plaster |
|---|---|
| Moisture rising from the ground via capillary action | Old damp plaster continues to draw moisture from the air |
| Usually has tide marks + active high moisture | May feel dry but shows white salts or bubbling |
| Hygroscopic salts may not dry out even after DPC | Moisture readings on meter may be false positives |
| Needs DPC injection + wall prep | Often just needs breathable salt-inhibiting render |
What Is a Salt Inhibitor?
A salt inhibitor is an additive used in specialist render or plaster to neutralise hygroscopic salts — the kind that continue drawing moisture from the air even after a wall has dried.
We use breathable plaster systems (like renovating plaster) that:
✅ Prevent salt migration
✅ Allow moisture to evaporate
✅ Don’t trap water like standard gypsum
✅ Provide a clean, dry finish
When to Choose a DPC + Salt Inhibitor
You may need both if:
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The existing DPC has failed or been bridged
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Moisture is rising from ground level
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Salts are present and the wall is actively damp
We’ll always recommend the minimum intervention needed — no unnecessary upsells.
How We Assess Your Wall
Our Level 3 qualified damp specialists in Blackpool carry out:
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Moisture readings (deep + surface)
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Visual signs of bridging or bridging plaster
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Salts testing and surface pH checks
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Sub-floor ventilation checks
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External ground level inspection
All assessments are free with no obligation.
Why Blackpool Homeowners Choose Weather Wise
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✅ Family-run and trusted in the North West
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✅ Level 3 qualified damp specialists
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✅ Members of the Damp Proofing Association
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✅ CPD-certified in Dampness in Buildings
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✅ Honest, no-pressure quotes — just what your property needs
Book Your Free Damp Survey in Blackpool
https://weatherwiseuk.co.uk/pages/contact
FAQs
Do I always need to re-plaster after a DPC?
If salts are present or plaster has bridged the floor, yes. Even with a new DPC, the wall won’t dry properly if the plaster traps moisture.
Can I just use anti-mould paint instead?
No — anti-mould paint only hides the symptom. Salts will still migrate and damage the finish.
Will you test the wall before recommending anything?
Yes. We never quote for damp work unless we’ve inspected for bridging, ventilation, and moisture sources.