Why your loft ventilation matters more than you think

Most homeowners think of the roof as just tiles and felt. But the loft space below matters just as much. Poor ventilation causes real damage.

What poor ventilation causes

• Condensation on the underside of the roof deck
• Wet insulation that loses effectiveness
• Timber rot in rafters and wall plates
• Mould growth in the loft
• Shortened roof lifespan

What good ventilation looks like

For a typical Wimbledon home, you need:

• Continuous eaves vents (slot vents under the fascia) on BOTH sides of the house
• OR roof vents / tile vents distributed across the roof
• Adequate loft insulation that's not blocking the eaves

The insulation trap

The most common Wimbledon loft issue: insulation pushed right up to the eaves, blocking the airflow. The insulation should stop short of the eaves by 50mm or so to allow air movement.

If you can't see daylight at the eaves when you're in the loft, your ventilation is compromised.

What to do

Check your loft once a year (preferably in winter). Look for:

• Condensation on rafters or underside of felt
• Daylight at eaves
• Mould or dark stains on timber

Any of these means you need more ventilation. A roofer can install eaves vents or tile vents in a few hours. Cost: £200-£500 typically.