Can old roof tiles be reused on a new roof?

The covering and the fixings under it age at different rates, which is why reuse is possible at all. Marley reports a 60-year minimum for clay, a figure that comes from the Building Research Establishment, and about 60 years for concrete, while CORC reckons slate that has been maintained can pass 100 years. A tile can easily outlive the nail that held it.

A roof that has failed because of rotten battens, a worn underlay or slipped fixings may therefore still carry perfectly good tiles. Slipped slates, for instance, are often a fixing problem and not a slate problem.

Take care with very old roofs. Building Conservation cautions that a 60-year rule of thumb is a poor guide to handmade peg tiles, so those are judged by looking at them one at a time rather than by their age. A tile that rings clean and sits flat on its neighbours has plenty of life left, whatever the date on the house.

When the covering comes off, the crew lowers the tiles to the ground by hand and does not throw them into a skip. That matters because a reusable tile is only as good as its handling. They are stacked, then examined one at a time for cracks, chipped edges, flaking faces and damaged nibs, the small lugs that hang a tile on its batten.

Some tiles will not pass. Others will, but not for the front of the house, so the better ones are kept for the slope most visible from the street. A tile with a flaw that does not affect its job, such as a chipped corner hidden under the overlap, can be used where nobody will see it.

Do not expect every tile to return. Breakage during removal and failure on inspection both take a share, and the rest is made up in other ways. A survey cannot give an exact count, because the number depends on how the tiles come off the roof.

Because some tiles fail, a reused roof almost always needs extras. There are two routes: reclaimed tiles from a salvage yard, which are old and weathered like yours, or new tiles picked to blend in. Which is better depends on the roof and on how closely colour and texture must agree, and on what is available in your tile size when the order goes in. Our answer on matching old roof tiles goes through the options.

Where a house has several slopes, the simplest plan is to keep the originals on the front elevation and put the nearest matches at the back. Alternatively the crew can scatter the newer tiles across one slope, which blends over time better than a patch of obviously different colour.

If the match is poor or the quantity short, you hear about it before work begins, with the options shown in photographs. The written quote then states the covering that has been priced, as one total.

Reused tiles go back onto a new structure. That means new underlay, new battens wherever the old ones are not sound, and fixings to current practice. The ridge gets its own mechanical fixings too, in line with BS 5534 since its 2014 revision, and not mortar alone.

BSI itself concedes a limit. Even the code of practice admits that its advice may not suit some old roofs, particularly where reclaimed or traditional stock is going back on. A handmade tile may not accept a standard clip or nail in the usual way, so the fixing is chosen for the tile in the roofer's hand, not copied from a catalogue.

Since the reused covering weighs about what the old one did, the 15 per cent weight test described in the Planning Portal guidance is unlikely to come into play. Even so, put your particular job to building control, since the answer turns on the whole structure and not only the tiles.

In a conservation area, keeping the original covering is often what the council would like to see, and a modern substitute can be the harder case to argue. For the Steyne area, Arun District Council's guidance urges reinstating natural slate or plain clay wherever an unsuitable material has displaced it. Along Aldwick Road it calls for original roofing to return and remarks that concrete interlocking tiles have been laid where slate once was.

A listed house needs listed building consent for work affecting its character, which makes reuse the safer route in most cases. Ask the planners at Arun District Council, or at whichever council covers your address, before work begins. Our guides on roof work in Bognor Regis conservation areas and re-roofing a listed building cover the details.

None of this changes the basic position that sound material is worth keeping. For the wider picture of replacement work, see roof replacement and new roofs.