Why Devon's Damp Climate Affects Your Home (And What to Do)

Devon's mild, wet climate is great for gardens but challenging for houses. The high humidity affects everything from windows to wardrobes. Here's what you're dealing with and how to manage it.

The Devon Moisture Problem

The facts:

• Devon gets 30% more rainfall than the UK average
• Relative humidity is consistently high (80%+ many days)
• Mild winters mean damp rather than crisp, dry cold
• Coastal areas get salt-laden moisture too

What this means for homes:

• More condensation
• Greater mould risk
• Wood absorbs more moisture
• Drying washing takes forever
• Some "damp" problems are actually climate, not building faults

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Common Problems in Devon Homes

1. Condensation

What you see:

• Water on windows every morning
• Damp patches on cold walls
• Mould in corners and behind furniture
• Musty smell

Why it happens: Warm, moist air hits cold surfaces. In Devon's humid climate, there's more moisture in the air to begin with.

Solutions:

• Improve ventilation - Open windows, use trickle vents, run extractor fans
• Reduce moisture sources - Dry clothes outside or in tumble dryer, cover pans when cooking
• Add heating - Warmer surfaces = less condensation
• Consider a dehumidifier - Effective in the worst rooms

2. Mould Growth

Where it appears:

• Window reveals and frames
• External wall corners (especially north-facing)
• Behind wardrobes against outside walls
• Bathrooms and kitchens

Why Devon's worse: More moisture + mild temperatures = ideal mould conditions. Mould grows when relative humidity stays above 70% for extended periods.

Solutions:

• Kill existing mould - Proper mould spray, not just bleach
• Address the moisture - Ventilation, heating, dehumidifiers
• Improve air circulation - Pull furniture away from cold walls
• Check for damp - Some mould is caused by water ingress, not condensation

3. Damp in Walls

Types of damp:

Rising damp - Water rising from ground up walls

• Actually quite rare
• Often misdiagnosed
• Shows as tide marks up to ~1 metre
• Usually only affects old properties without damp courses

Penetrating damp - Water coming through walls

• Much more common
• Caused by failed render, pointing, or flashings
• Devon's rain drives moisture into walls
• Worse on the prevailing weather side (usually SW)

Condensation damp - Moisture from inside the house

• Most common "damp" problem
• Often misidentified as rising or penetrating damp
• Solution is ventilation, not damp-proofing

How to tell: A proper damp survey (not a free one from a damp-proofing company) will identify the cause. Or: if the problem is worse in winter and near cold spots, it's probably condensation.

4. Wood Swelling

Affected items:

• Doors that stick seasonally
• Windows that won't open
• Floorboard gaps that change
• Flat pack furniture that warps

The cycle: Autumn/Winter: Wood absorbs moisture, swells Spring/Summer: Wood dries slightly, shrinks

Solutions:

• Accept some seasonal movement
• Seal all wood surfaces (especially edges)
• Adjust doors for their worst state
• Use moisture-stable materials where possible

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Rooms That Suffer Most

Bathrooms

High humidity from showers and baths, often poor ventilation.

Must do:

• Run extractor fan during and 20 minutes after showering
• Wipe down wet surfaces
• Keep window open when possible
• Re-silicone when seals fail

Kitchens

Cooking generates huge amounts of moisture.

Must do:

• Use extractor hood every time you cook
• Cover pans
• Vent tumble dryers outside (or use condenser)
• Don't dry clothes on radiators

Bedrooms (Especially North-Facing)

We breathe out moisture all night. Cold rooms + warm bodies = condensation.

Must do:

• Ventilate in morning (open windows)
• Keep furniture away from cold walls
• Don't block radiators with furniture
• Consider background heating overnight

Single-Skin Extensions

Old conservatories and extensions without proper insulation are condensation traps.

Options:

• Improve insulation
• Install dehumidifier
• Accept moisture or improve heating
• Upgrade construction

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Practical Devon Home Tips

Daily Habits

• Open windows for 10-15 minutes daily (even in winter)
• Use extractor fans properly
• Dry clothes outside when possible
• Wipe condensation from windows

Maintenance

• Check gutters and downpipes regularly (Devon rain tests them)
• Keep air bricks clear
• Re-point any failed mortar
• Check window and door seals annually

Heating

• Maintain steady temperature rather than extreme swings
• Don't turn heating off completely in winter (encourages condensation)
• Background heating in unused rooms helps

Ventilation

• Don't block trickle vents
• Consider positive input ventilation (PIV) systems
• Keep internal doors open when heating (airflow)
• Extract humidity at source (fans where steam is created)

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Dehumidifiers: Are They Worth It?

Yes, if:

• You have a persistent condensation problem
• Room can't be adequately ventilated
• Drying clothes indoors regularly
• Single-glazed or very cold rooms

Types:

• Refrigerant: Best above 15°C
• Desiccant: Work better in cold (good for UK)

Running cost: Roughly 3-5p per hour. If it stops mould damage, worth it.

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When to Call a Professional

Get expert help for:

• Persistent damp despite improving ventilation
• Suspected penetrating damp (roof, walls)
• Mould that keeps returning
• Structural concerns from damp

Get an independent surveyor for:

• Damp diagnosis (not a company selling treatments)
• If you're buying a property with apparent damp

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Damp problems in your Devon home? I can assess what's going on and suggest practical solutions. Call 01392 964094 or get a quote.