Is Damp Coming Through Your Walls in Wigan? Here’s Why.
If you’ve spotted moisture patches on your internal walls, flaky paint, or signs of plaster damage — particularly at the base of external walls — the culprit may not be rising damp.
Instead, many Wigan homes suffer from lateral damp, where moisture pushes sideways through walls due to:
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High external ground levels
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Poor drainage or water pooling near walls
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Solid brick construction with no cavity
The solution? You’ll often hear two main options: tanking slurry or French drains. Let’s explore the difference.
What Is Tanking Slurry?
Tanking slurry is a cement-based waterproof coating applied directly to walls to block water ingress. It creates a physical barrier that prevents moisture from entering, even under pressure.
✅ Best for:
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Basements and below-ground walls
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Solid external walls with no cavity
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Where lowering ground levels is not possible
🚫 Limitations:
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Doesn’t stop the cause — only blocks it
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Needs correct surface prep and breathable finish internally
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If bridging occurs (e.g. with impermeable paint), it can fail
What Is a French Drain?
A French drain is a gravel-filled trench with a perforated pipe that diverts water away from your property. It sits externally, usually along a wall that’s below ground or backed by a hill.
✅ Best for:
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Reducing water pressure against walls
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Long-term prevention of lateral moisture
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Homes with waterlogged soil or visible runoff
🚫 Limitations:
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Needs excavation and space
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Doesn’t stop water that’s already entered the wall
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Can clog over time if not maintained properly
So, Which One Do You Need?
| Situation | Best Option |
|---|---|
| Wall already damp, no cavity | Tanking Slurry |
| High ground levels outside | French Drain |
| Below ground level (e.g. basement) | Both |
| No space for a drain | Tanking |
| Damp on internal face only | Tanking or internal barrier |
| Moisture showing externally and pooling water present | French Drain |
In Wigan, we often recommend a combined approach where we:
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Install a French drain to reduce external pressure
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Apply tanking slurry to protect internal finishes
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Use a breathable plaster system or render finish internally
What Happens If You Do Nothing?
Without treatment, lateral damp can lead to:
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Plaster failure and decoration damage
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Mould and condensation from trapped moisture
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Rotting skirtings or floor timbers
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Internal salt contamination
Why Wigan Homeowners Trust Weather Wise
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✅ Level 3 qualified damp & timber surveyors
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✅ Full damp diagnosis including moisture mapping
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✅ Members of the Damp Proofing Association
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✅ Federation of Damp accredited
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✅ Family-run with a reputation for honest, no-pressure advice
Book Your Free Damp Survey in Wigan
https://weatherwiseuk.co.uk/pages/contact
Quick FAQs
Can I install a French drain and skip tanking?
Only if the drain fully removes pressure and the wall is still sound. We’ll inspect first.
Is tanking breathable?
No. It's a barrier. That’s why we pair it with ventilation and breathable internal finishes.
Will I need to dig around the property?
For a French drain — yes. But we keep disruption minimal and plan around your access and layout.