By Charlie the Roofer for Roofline · Published · Checked against the sources listed below
Yes, one missing tile matters, but it is not always urgent. On most concrete tile roofs the gap leaves only the underlay between rain and your loft. If the loft is dry and the gap is high up, waiting for a calm spell is usually fine. Near the eaves or verge, or over old felt, get it fixed sooner.
What does a missing tile leave exposed?
A missing tile leaves the underlay, and the battens the tiles hang from, open to the weather. Underlay is the sheet of felt or membrane under the tiles. The NFRC describes it as a secondary line of defence against wind-driven rain and snow, there to catch water that gets past the tiles and drain it to the gutter. It is a backup, and underlay makers advise keeping its exposure to sunlight as short as possible.
How much is open depends on the roof. Concrete interlocking tiles, the usual covering on post-war Yorkshire semis, are single-lap: each tile overlaps the one below and locks into the tiles beside it, so a missing one leaves a hole straight down to the underlay. Natural slate, found on many Victorian terraces, is double-lapped, as Marley points out. A missing slate still leaves the course below, but the joint underneath it is now open to rain.
Some older slate roofs were built with no felt at all. On those, a gap lets rain onto the battens and into the loft with nothing in between.
Why does it matter where the gap is?
Position matters because water and wind do not hit a roof evenly. A gap near the eaves sits under all the rain running down the slope above it. A gap a course or two below the ridge takes far less water.
Edges also take more wind. That is why BS 5534, the British Standard for slating and tiling, has asked for two fixings on every perimeter tile since its 2015 amendment. Many older roofs were not fixed that way, so once one edge tile has gone, the wind can get under the tiles beside it in the next gale. Our BS 5534 guide explains the fixing rules.
How long can you safely leave it?
How long you can wait depends on what is under the gap, and your loft will tell you most of it. On a dry day, look with a torch at the underside of the roof below the gap. If you can see daylight through the felt, or wet timber and stained insulation, water is already getting in and the repair should not wait. A dry loft with intact membrane under a gap high on the roof can usually wait for a calm, dry spell. A zoomed phone photo from the garden also shows whether the gap has membrane or old black felt in it, or nothing but battens. Our guide to finding a roof leak covers safe checks from the ground and the loft.
Do not let it run into winter. Cadw's roof guidance says a few minor repairs can save thousands of pounds later, and Northern Ireland's Department for Communities notes that slipped slates do not always let water in at first, which is how small faults get missed. Keep checking the loft after heavy rain until it is fixed. Never go onto the roof or up a ladder to it yourself: Cadw advises hiring a contractor rather than risking a serious accident.
On a terrace, one slope often runs across several houses. If the gap is above next door, tell your neighbour, because it is usually theirs to arrange and a roofer will need their agreement to work on it. Check your own loft near the party wall as well.
Will your insurance pay if you leave it?
It may not. The Financial Ombudsman notes that many home insurance policies exclude wear and tear and gradual damage, and a leak through a gap that has been left open may be put down to those rather than to a storm. When the Ombudsman looks at a refused storm claim, it asks whether there was a storm, whether the damage looks like storm damage and whether the storm was the main cause. It is also unlikely to back you if the roof was already in poor condition and you knew about it.
If a storm took the tile, photograph the gap from the ground, note the date and read our storm damage and insurance guide. The easiest next step is to send that photo to Roofline on WhatsApp at 07413 797731, or book a free inspection and we will send you photos of what we find.
Send us a photo on WhatsApp and we will tell you what we think it is and whether it needs a visit. Quotes are free and itemised.
Sources
- NFRC, Roof Underlays (January 2021)
- Marley, Slates (Edgemere interlocking slate)
- Department for Communities (NI), Technical note: roofs
- Marley, Changes to the British Standard for Slating and Tiling BS 5534
- Cadw, Roofs
- Financial Ombudsman Service, Storm damage
General information about roofing in England, checked against the sources above when published. It is not a substitute for advice about your own roof.
