The short answer
They can, if the system is badly fitted or damaged. A correctly fitted dry ridge leaves no open run for a bird to walk into, but the ends of the ridge, the junctions with hips and any slipped or cracked unit can open a gap. A roofer closes those gaps with end caps, closers and filler before a bird finds them.
Sparrows and starlings are good at finding a hole. Most of the work is spotting where a dry ridge has been left open and shutting it properly.
Where a bird finds the gap
A dry ridge is a line of ridge tiles clipped or screwed down onto a batten, with a ventilated strip tucked in beneath them to keep the weather out. The ridge itself is the high line where the two slopes of a roof meet. Done well, there is no open tunnel along it. Birds look for the places where that line is broken.
Which parts of the ridge are the weak points?
The first is the very end of the run, where the last ridge tile meets a gable. If the end is left without a cap or a closer, the hollow under the tile is open to the sky. The second is the junction where a ridge meets a hip, because several cut pieces come together there and small gaps are easy to leave. The third is damage: a ridge tile knocked loose by wind, or a roll that has lifted along one edge, leaves a slot just wide enough for a starling.
Eaves are the other common route. The gap where the bottom row of tiles overhangs the gutter lets air in, and without a comb filler or a mesh strip it also lets birds in under the tiles.
Closing the ridge ends and the junctions
Every dry ridge kit includes parts for the ends of the run, and those parts do the bird-proofing. A roofer fits an end cap, a moulded piece that closes the open end of the ridge tile, and a ridge closer, a shaped insert that fills the space between the tile and the roof covering below it. On a plain tile roof the profile of the tile decides which closer fits.
Does bird-proofing stop the roof breathing?
It should not. The ventilated roll or strip under a dry ridge is made to let moisture out of the loft while stopping rain and wind-driven snow coming in. A mesh or comb that is cut to fit the roll's openings keeps birds out and leaves the air path alone. Stuffing a ridge with foam or loose mortar is the wrong way to do it, because it blocks the airflow that keeps timber dry. Ventilation in a cold loft follows BS 5250, and our page on the ventilated dry ridge explains how the ridge takes part in it.
At a hip junction we cut and seat each tile so the joint is tight, and use the manufacturer's closer rather than a handful of mortar.
Nest law and timing the work
If a bird has already moved in, stop before the roof is touched. Section 1 of the Wildlife and Countryside Act 1981 turns on intent: the offence is to damage or destroy, intentionally, a nest that is in use or being built. Knocking a nest by accident is a different matter from clearing one on purpose, and the second is where the law bites.
Can you work on a ridge with a nest in it?
GOV.UK's wild bird guidance names no licence purpose covering development or construction, so a deadline for the work is not an excuse. In practice the job either waits until the chicks have flown, or the roofer works on stretches of ridge away from the nest. Once the nest is empty, the gap gets closed so the same thing cannot happen next spring.
Bats are a separate case. Section 9(4) of the same Act applies where someone intentionally or recklessly disturbs a bat roosting in a structure, or obstructs its way in. GOV.UK includes roof repair among the work that may affect bats. If we find droppings or hear squeaking under the ridge, work pauses until specialist advice is in hand.
What we check when you call
Birds in a ridge usually point to a ridge that was not finished properly, or has been damaged since. We start with a survey, and you see photos of your own ridge, ends and hips included, before any price is given. If the gap is a missing cap on a new-build ridge, the repair is small. If the units themselves have slipped, we check the fixings along the whole run, because one loose unit often sits beside others that are on the move.
Is a bird in the ridge a sign the system has failed?
Not always. A bird can use a gap left at the end of an otherwise sound ridge. But a bird that gets in can also push a roll out of place, and a displaced roll lets rain in at the joint. Our page on dry ridge failure sets out the other signs to look for.
The way the whole system goes together is on our dry ridge and verge page. Pictures of the ridge ends taken from the garden, with the zoom on your phone, tell us a good deal before anyone climbs up. Attach them to your enquiry and the reply covers what the survey needs to look at.
More on birds and ridges
Is it against the law to clear a nest from my roof?
Wildlife law bites where someone intentionally destroys or damages a nest with birds in it or one still being built. Wait until the nest is empty and the birds have left for good. After that, closing the gap with the right parts stops the birds coming back.
Will mesh at the ridge ends cause damp in the loft?
Not if it is the right kind. The mesh or comb has to leave the openings of the ventilated roll clear, so air still moves through the ridge. Blocking a ridge with foam or mortar is what causes trouble, because trapped moisture settles on the timber.
The full picture: Dry ridge and verge repairs in Taunton ยท More short answers