How to fix a leaking conservatory roof

A leaking conservatory roof is one of the most common complaints owners have: in Which?’s April 2026 survey of its members, leaks were the third biggest conservatory regret, named by 9%. The good news is that most leaks start in one of a handful of places, and many can be repaired. The work is in finding the right one.

Is it a leak or condensation?

Rule out condensation first, because it looks like a leak and has a completely different fix. Condensation appears on cold mornings whether or not it has rained, and forms across the whole underside of the roof, then drips. A leak appears during or after rain, from one spot, or along one glazing bar or wall. If yours matches the first description, read our page on conservatory condensation instead.

Where is your conservatory roof leaking?

Water can run along a bar or the underside of the roof before it drips, so the place it lands is not always where it gets in. Start from where it appears and work uphill.

Where the water appears	Likely cause	What to check
Along the front edge, above the windows	Blocked or overflowing gutter or downpipe	Leaves and silt in the gutter; whether the downpipe runs freely
Where the roof meets the house wall	Failed flashing or sealant, or water coming down inside the house wall	See leaks where the roof joins the house
At the ridge or apex	Ridge cappings, end caps or seals	Lifted or missing caps, cracked sealant
Along a glazing bar	Worn gaskets or sealant under the bar cap	Gaps along the cap
Around a roof vent	Worn vent seals	Whether the vent closes fully
From the middle of a panel	Cracked, holed or slipped panel	Cracks, or a sheet that has slid down
A roof fitted in the last few years	Installation fault	Your installer’s guarantee (see below)

The first five come straight from Which?’s list of common causes: blocked gutters and downpipes, panels damaged by weather or poor installation, worn sealants and roof vents, and flashing problems. LABC adds one more at the house wall: foundation movement can cause cracks and water leaks where the conservatory meets the house.

How to fix a leaking conservatory roof

1. Stay off the roof. Ultraframe says it is not safe to stand directly on a conservatory roof, and that special ladders can be hired for maintenance access.
2. Rule out condensation. Check whether the water appears only after rain.
3. Clear the gutters and downpipes. Which? names blocked gutters as a common cause, and it is the cheapest fix there is.
4. Find the entry point in the rain. Note where drips land, then trace the bar or joint above it, uphill.
5. Reseal joints, vents and cracks. Which? suggests reapplying weatherproof sealant. On self-cleaning glass, Ultraframe’s installation guide says to use MS polymer sealant, not ordinary silicone.
6. Replace loose or cracked panels. A single sheet or glass unit can usually be swapped; see our page on a cracked roof panel.
7. Get the flashing checked where the roof meets the house wall.
8. Call in a roofer if it still leaks, or leaks in more than one place, and ask for the cause in writing.

How much does it cost to fix a leaking conservatory roof?

MyJobQuote puts a typical conservatory roof leak repair at around £375, and another price guide, Home Improvement Quote Today, gives £500 to £2,000 for repairs. We found no reliable published figure for resealing a whole roof, so get a written price that says exactly what is included.

For comparison, one couple’s DIY account of re-sheeting a lean-to with 25mm polycarbonate put the materials at £324, with two people working a full day. And if the roof is past saving, these are typical fitted prices for a medium conservatory (about 4m x 3.5m). Installers usually quote including VAT, but check:

New roof	Typical cost
New polycarbonate	£2,700 to £5,200
Insulated panels	£1,800 to £4,600
Glass	£3,500 to £7,000
Tiled	£7,400 to £12,100

Which? members who replaced a roof reported an average cost of £6,144 in its April 2026 survey. Our conservatory roof costs page breaks prices down by style and size.

Will home insurance cover a leaking conservatory roof?

Often not. The ABI lists general wear and tear, and damage due to lack of maintenance, among the things home insurance does not cover. Sudden damage, such as from a storm, may be covered depending on your policy.

If a storm claim is disputed, the Financial Ombudsman Service asks three questions: were there storm conditions on or around the date, is the damage consistent with a storm, and was the storm the main cause. Claims can fail where the roof was already in poor repair and the storm only exposed it. The ABI advises contacting your insurer promptly, photographing the damage and keeping receipts for emergency repairs. Our conservatory roof insurance guide has more.

New conservatory roof leaking?

Go back to the installer first. Under the Consumer Rights Act 2015 a trader must perform a service with reasonable care and skill, and you can require them to put it right at their cost, within a reasonable time. Goods that were installed incorrectly by the trader do not conform to the contract.

Check your paperwork too. Several firms advertise 10-year workmanship guarantees, and some mention leaks by name. If the installer has stopped trading, an insurance-backed guarantee is what should step in. Our guide to conservatory roof guarantees explains the different types.

Should you repair or replace a leaking roof?

Repair it if the leak is in one place and the roof is otherwise sound. Replace it if:

• it leaks in several places, or you have already paid for repairs that did not last
• it is polycarbonate that has discoloured or gone brittle (most seller and review-site estimates put polycarbonate’s life at 10 to 20 years)
• it is also too hot in summer or too cold in winter
• there are cracks or movement where the conservatory meets the house, which LABC says needs checking before any heavier roof goes on

A new polycarbonate roof is one of the cheapest ways to stop a failing roof leaking. A glass, panel or tiled roof costs more but fixes the comfort problems at the same time.

When you get quotes, ask each roofer or installer to state in writing what is causing the leak, what the repair or new roof includes, and what guarantee comes with it.