What Is an Eaves Protection System?

The problem it solves

The roof edge, or eaves, is where three things meet: the felt under the tiles, the fascia and gutter, and the ventilation gap into the loft. If any of them is detailed badly, water or pests get in. Roofing felt sags between rafters and holds water. The felt may stop short of the gutter, so water that gets under the tiles runs behind the fascia. A gap below the tile edge lets birds, wasps and bats in. The loft may be starved of air, which causes condensation.

An eaves protection system sorts these out with a set of low-cost parts, fitted as one detail. It is not a single product but a combination, and different makers sell versions of it. The aim is always the same: keep the edge dry, ventilated and sealed.

The parts, one by one

The main components are:

• Eaves tray or felt support: a shaped plastic tray that sits on the fascia and under the felt, carrying water into the gutter and stopping the felt from sagging.
• Eaves carrier or fascia support: a strip that holds the felt at the right angle between the rafters.
• Ventilation: a vent strip over the fascia or a vented soffit board, letting air into the roof space. Our page on soffit ventilation explains why this matters.
• Comb filler or bird guard: a strip with teeth or slots that fills the gap between the bottom tiles and the fascia, blocking birds and insects but allowing air through.
• Insect mesh: fine mesh in vents, which keeps out wasps and flies.

Not every house needs every part. A roof with an overhang and a vented soffit may need only the tray and the comb filler.

Take the felt support as an example, since it does the most work. The tray is a shaped strip, often with a gentle slope, that fixes over the top of the fascia and under the felt. It lifts the felt out of the gap, gives it a continuous downhill line and delivers every drop into the gutter. Without it the felt sags between rafters, like a hammock, and water sits in the sag and soaks the rafter ends. The tray is cheap, light and quick to fit when the eaves are open, which makes it one of the best-value parts of a roofline job.

Ventilation is the other half. Moist air leaving the rooms below drifts up into the loft, and if it cannot escape it condenses on cold timber and felt. Air entering at the eaves and leaving at the ridge keeps the roof space dry. A vent strip behind the fascia or a vented soffit gives the incoming path, as long as insulation in the loft is not pushed hard against it. Where the insulation blocks the gap, a plastic baffle holds it back.

When it is fitted, and when it is missing

Many older roofs have none of these parts. The felt is cut short, tucked behind the fascia or even trapped under it, and the bottom tile sits on bare timber. Water that gets under the tiles runs down and soaks the fascia. A rotten fascia is often the sign. If the same board rots again after replacement, it usually means the eaves detail was never fixed. Our page on rotten fascia boards deals with the decay, and water running behind a gutter describes how the problem shows itself.

The best time to fit the system is when the fascias and soffits are replaced, because the eaves are open and the felt can be reset. It can sometimes be added to an existing roof by lifting the bottom row of tiles, which is covered in replacing fascias without disturbing the roof.

What we do at the eaves

When we replace a roofline, we check the felt, fit a tray where it is missing, restore the vent and close the gap with a comb filler. The loft stays ventilated, birds stay out and the new board stays dry. Where nesting birds are using a gap, we wait until the young have left, as set out in birds nesting in soffits and fascias. The full order of work is in the roofline replacement process.

Our free survey photographs the eaves from above and below where access allows, and tells you plainly whether your roof has a proper eaves detail. If it needs one, we say what it involves. The cost is small beside scaffold and boards, and fixed written figures follow the survey. The wider service is set out on our guttering, soffits and fascias hub.