Can leadwork be done in wet or cold weather?

What cold does and does not do to lead

Lead is soft and stays that way in low temperatures. Unlike a plastic membrane or a bitumen product, it does not go stiff and brittle in frosty weather, so a leadworker can bend, dress and form sheet on a cold day much as on a mild one. That is one reason lead has been fixed to roofs throughout the year for centuries.

Temperature does matter in one respect: movement. Lead expands when warm and contracts when cold. A sheet laid on a very cold morning is at its smallest, so it needs room to grow in summer. A sheet laid in hot weather is at its largest and needs room to shrink. Good leadwork allows for both by using the right lengths, drips and clip fixings, as described in our answer on why lead cracks. A well-laid winter job and a well-laid summer job should perform the same way.

The real constraints in winter are practical. The deck must be dry. The sheet must not be blown about. The leadworker must be able to stand and work safely. And any other material used with the lead has to cope with the conditions. These are the points that decide whether a job goes ahead or waits.

Wet surfaces and frost

Water is a bigger problem than cold. Lead is laid over boards or a similar deck, usually with a separating layer between them, and the deck needs to be dry when the lead goes down. If damp timber is covered over, moisture is trapped beneath the sheet. It cannot escape, so it stays against the underside of the lead and the boards, causing rot in the timber and, over time, corrosion on the underside of the metal.

Frost and ice create a similar problem. A film of ice on the deck stops the lead sitting flat, makes fixing unreliable and melts into the joint when the sun comes out. We do not lay lead onto a frosted surface. We wait for it to clear, or, if the work cannot wait, deal with it by clearing and drying the area first.

Rain interrupts leadwork for the same reason. Opening a gutter in a downpour means water pours onto the deck and into the house below. In wet weather we keep exposure to a minimum, working in sections that can be closed up the same day. A section that has been opened up and then left to the weather is a section that will leak.

If lead has been working well and a leak appears in winter, that does not mean the lead is the cause. Gutters often overflow in wet weather because of leaves and moss, as our answer on why a parapet gutter leaks explains.

Jobs that suit winter and jobs that are better delayed

Many lead jobs can safely go ahead in the cold if there is a dry window.

• Replacing a failed flashing or a short run of valley. Small, contained jobs can be completed and sealed in a day, so they are less exposed to the weather.
• Cutting out and renewing a split bay. The repair is local and quick, and stopping a leak in winter protects the house.
• Renewing lead after theft. The roof is open, so the work usually has priority, as we cover in our answer on stolen lead and insurance.
• Clearing and checking a gutter. A survey and a clear-out can be done in almost any dry spell, and are a good idea after autumn leaf fall.

Other work is better delayed until conditions improve.

• Lead welding. The joint is made by melting the edges of two sheets together, which needs clean, dry metal and a sheltered working area.
• Pointing and wedging flashings into masonry. Fresh mortar can be damaged by frost before it sets, so lime or other mortars are best used when frost is not forecast.
• Self-adhesive products and sealants. Many do not bond properly to cold, damp surfaces. They are not our first choice for lead at any time, but they are least reliable in winter.
• Large flat roofs and complete re-lays. A big area open to the elements for days at a time is risky in unsettled weather. We programme these for a drier period unless the roof is already failing.

Wind, ice and working at height

Even where the lead and the deck allow work, the weather can stop it. A sheet of lead has weight, but a large piece held up on a windy day acts like a sail. It can tear from a worker's hands, bend or kink, and fall. A crimped or kinked sheet needs to be flattened again or replaced, and every kink is a place where fatigue can start later.

Access is the other issue. Parapets, gutters and valleys are narrow, and in winter they are slippery. Scaffolding or edge protection should be in place for any serious work at height. Frost on a ladder, an icy parapet coping or a wet lead gutter makes a hazard where there is little room to recover from a slip. We would rather wait a day than push on in conditions that put someone at risk or damage the roof.

As a practical matter, short winter days also limit how much can be done. A job planned to be opened and closed within one day may need to start early and stop on time, with a clear plan for what is left covered overnight.

Leaking now: temporary measures and next steps

If water is coming in during winter, the roof does not have to wait for perfect conditions to be made safe. Water coming through is stopped before anything else. That might mean clearing an outlet, covering a split with a temporary membrane, supporting a loose flashing or boarding over an open section. These measures are quick and are designed to hold until the permanent work can be done in better conditions.

A temporary cover is not a repair. It stops the immediate leak, and the permanent fix follows once the weather allows. We explain which is which, so you are not left thinking the problem is solved when it is only paused.

Before permanent work, check that you understand the code of lead proposed. Our page on lead codes explains what the thicknesses mean, and it is a useful question to ask any roofer who is quoting.

You pay nothing for the survey, and our pictures of your roof explain what we found; a written fixed price comes next. If the survey shows the job can safely go ahead this week, you will hear that. If it is better to wait for a dry spell, we say that instead, and tell you what is being done in the meantime. The overall range of lead work we cover sits under lead roofing.