What are lead soakers?

Picture the edge of a roof where the slope butts against a brick wall. Rain runs down the slope and also down the wall, and the two meet at an awkward corner. A soaker is a rectangle of lead, bent along its length into an L. One leg lies flat under the tile or slate, the other turns up the wall. Any water that creeps under the edge of the covering lands on the soaker and is sent back out onto the roof.

One soaker goes in with every course of tiles, which is why a long abutment can hold dozens. Above them, a separate stepped strip of lead is set into the wall and laps over the upturned legs. Trade people call that the step flashing. Between them the two pieces seal a joint that moves a little with the weather and with the house, and neither does the job alone. Take the soakers out and the flashing has nothing to shed water onto.

You find them at the side of a chimney stack, along a gable wall where a roof abuts a taller building, on dormer cheeks and beside party walls. They suit coverings made of small units, such as plain clay tiles and natural slate, because each course can have its own piece of lead. Larger interlocking tiles tend to be handled in other ways, and your roofer will tell you which applies on your roof.

Lead is chosen because it folds to a tight angle and stays put. A thin strip of stiff metal would split at the corner, and a bead of sealant could never take the place of a soaker for long. The detail is out of sight once built, so it has to be right first time. That hidden care is part of what a square finish means to us: the parts nobody sees are done as well as the parts everybody sees.

Lead comes in numbered codes, each one a fixed thickness and weight. Royston Lead's brochure on cast lead sheet recommends code 3, at 1.32 mm and 14.97 kg per square metre, for soakers only. Code 4, at 1.80 mm and 20.41 kg per square metre, is also listed for soakers, and for flashings too. Soakers are small and sit well protected under the covering, so the lighter codes carry the load.

Heavier lead is not wasted if you want extra thickness, but it is stiffer to fold and dearer to buy. The right code for your roof depends on the covering, the detail and what the roofer specifies, and the written quote names it. Our guide to lead codes sets out the whole range, and the answer on lead sheet weight lays the figures out in a table, so you can check what is being proposed.

Lead soakers rarely wear out quickly. The more common trouble is that they slip down, because the tile above has moved, or that someone has smeared sealant over a leaking abutment and left the real fault alone. A soaker can also split if it was folded hard against a cold, sharp edge, and on a patched-up job some courses may have been left without one at all.

Signs include damp on the wall beside the roof edge, a stain on the ceiling under the abutment, or edge tiles that have lifted. The leak can look like a flashing fault, so see our answer on why lead flashing leaks. MyJobQuote puts the typical life of lead flashing at more than 80 years, a guide rather than a guarantee, and soakers are cut from the same metal. A leak long before that age suggests something moved or was fitted badly, and the survey is where we find out which.

You cannot slide a soaker out from under a course of tiles and slide a new one in. The covering along the edge has to be lifted, course by course, and relaid with a fresh soaker under each. That is why the job is bigger than the lead involved suggests, and why we survey it before quoting. We photograph the abutment, count the affected courses and note whether any tiles are cracked.

If the tiles are sound they go back on. If they are brittle, the quote says so and shows what replacement would involve. Checkatrade's roof repair guide, updated October 2026, lists lead flashing repairs at £50 to £70 per metre, with VAT added. The survey ends in a written quote showing one total price, with the courses affected described in it. For the wider work, see the lead roofing and leadwork hub.