Across Stockport, Heaton Moor, Cheadle, Burnage, Reddish and Didsbury, the most common loft problem we see is condensation.

Homeowners come to us saying things like:

• “The insulation is wet.”

• “There are black spots on the rafters.”

• “The loft smells musty.”

• “Stored items feel damp.”

• “We’ve got mould on the timber.”

All of this usually points to one root issue:

Warm, moist air is rising into the loft and has nowhere to escape.

This article explains why that happens, what causes the damp, and how to fix it safely using LAP vents and proper airflow.

Why Condensation Happens in Lofts

Condensation forms when warm moisture from inside the home rises into the loft and hits cold surfaces.

Everyday activities drive moisture upward:

• Showers

• Cooking

• Bathing

• Washing/drying clothes

• General heating cycles

A modern roof has a membrane under the tiles (to keep water out), but this membrane often traps moisture inside if no ventilation is installed.

The result:

• Moisture settles on rafters

• Insulation gets damp

• Mould begins to form

• Wooden timbers darken

• The loft smells unpleasant

90 percent of the lofts we inspect in Stockport have insufficient or zero ventilation.

What Damp and Condensation Look Like

When we enter a loft, we look for:

1. Black or dark spots on rafters

This is early-stage mould.

2. Wet patches on insulation

Top layers become soggy in corners or near the eaves.

3. Moisture under roof felt

Condensation often collects directly under the membrane.

4. Musty or earthy smell

A sign of trapped moisture for a long time.

5. Damp storage boxes

Cardboard softening or stored items “feeling cold”.

6. Cold patches with no insulation

Heat escapes, driving more moisture upward.

If you see any of these, your loft’s airflow is failing.

How LAP Vents Fix Condensation

LAP vents (Loft Airflow Path vents) are small, discreet pieces of ventilation equipment installed between roof tiles and the membrane.

They create a continuous airflow path through the loft, allowing warm, moist air to escape naturally.

LAP vents solve:

• Condensation

• Damp patches

• Mould growth

• Wet insulation

• Poor airflow

• Stale loft smell

• Heat trapped under the roof

After installing LAP vents, lofts typically dry out within 2–6 weeks, depending on severity.

How Many LAP Vents Do You Need?

Most Stockport homes require:

• 6–12 vents for a typical semi-detached

• 4–8 vents for a terrace or bungalow

• More if there is visible mould or trapped moisture

Placement is important. We position vents to create a cross-flow pattern that stabilises the entire loft environment.

This is included in the Loft Health Survey.

Why Ventilation Matters More Than Insulation Alone

Even perfect insulation fails if moisture is trapped.

• Damp insulation loses most of its thermal value

• Cold spots develop

• Mould spreads

• Boarding becomes unsafe

• Wood can rot over time

That’s why we always assess airflow before installing the 100mm + 200mm insulation system.

Pricing for LAP Vents in Stockport

£8–£12 per vent

Installed professionally with correct spacing.

Most lofts need £48–£120 worth of vents.
You’ll receive your exact count after your £29 Loft Health Survey (waived if work booked).

Should You Replace Damp Insulation?

If insulation is:

• Damp

• Falling apart

• Patchy

• Mouldy

• Compressed

• Contaminated by rodents

…it should be removed and replaced as part of the airflow fix.

Insulation removal: from £10 per m²
New base layer (100mm): from £15 per m²
New top layer (200mm): from £15 per m²

Full 300mm system: £20–£30 per m²

Learn more here:
https://hiclimited.co.uk/loft-insulation-boarding-stockport

What Happens During a Condensation Inspection

During the Loft Health Survey, we check:

• Moisture levels

• Ventilation gaps

• Insulation depth

• Rafter condition

• Membrane condition

• Cold patches

• Airflow pathways

• Hatch leakage

You’ll receive:

• Photo evidence

• Written report

• Clear recommendations

• No-pressure quote

Survey cost: £29
Waived if you go ahead with the work.

Home Improvement Contractors Ltd
Also trading as: Heatons Handyman

Address : Heaton Moor, SK4 4NS

📍Serving Manchester | Reddish | Heaton Moor | Heaton Chapel | Edgley | Stockport | Denton | Hyde | Didsbury | Heaton Norris | Cheadle | Cheadle Hulme | Bramhall

Phone: 07441 356128

Monday–Saturday: 8:30 AM – 4:00 PM
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