Repair or Replace a Leaking Conservatory Roof

A conservatory roof leaks at its joints far more often than through its middle, and which joint changes the number by a factor of ten. It is usually possible to narrow it down from inside on a wet day.

1. Where it joins the house. Water tracking down the wall inside, or a stain at the top of the frame, points at the abutment: the flashing, or the cavity tray behind it. Flashing repair or replacement is £150 to £500. Worth knowing before anyone starts: building control cannot require a cavity tray to be retrofitted to the existing house wall, which is verified LABC guidance, so a quote that treats it as compulsory is quoting an opinion.
2. The ridge and the glazing bars. Drips along a line rather than at a point usually mean perished gaskets or end caps in the bars, or a ridge that has lifted. £200 to £600, and it is the repair most likely to come back if the roof is old, because the material around the new seal is the same age as the seal that just failed.
3. An individual panel. One panel weeping at its edge is the cheapest outcome on this page: £80 to £250 for polycarbonate, £150 to £450 for glass. If it is polycarbonate and the flutes have gone green, the panel is telling you about the whole roof rather than about itself, which is the argument laid out on your polycarbonate roof.
4. The box gutter. Overflow into the room, usually after heavy rain and usually in autumn, is a blocked gutter rather than a failed roof, and it is the one cause on this list that costs nothing to rule out. The safe way to check is on cleaning a conservatory roof.
5. A solid or tiled section. If a previous owner put a solid roof on, a leak is a repair to that structure at £300 to £1,200, and the diagnosis is slower because the water can travel a long way above the ceiling before it appears. If the roof is glass and several units have failed together, the replacement options are priced on replacement glass roofs for conservatories.

All figures installed and including VAT, single publisher, 27 July 2026, graded Thin, checked 20 August 2026. If the roof is coming off either way, use the Conservatory Cost Calculator before you book a repair, because the repair is only worth doing if the roof has years left in it.

The honest test is not the price of this repair, it is the price of this repair plus the next two. Most repair jobs land between £150 and £1,200. A reseal is £400 to £900 and buys you the seals, not the material under them. All those rows are single-publisher, 27 July 2026, graded Thin, checked 20 August 2026. On our own addition, three visits across four winters on a roof already twenty years old can reach £1,500 to £2,500, which is real money spent on a component you will still be replacing.

Against that, a tiled or solid roof on a 3m by 3m conservatory is £6,000 to £11,000 installed including VAT, typically £8,075. That figure is the strongest in our whole register: four independent publishers agree within 1.05x on where it starts, which is the tightest agreement in the file, and it is graded Well evidenced for that reason, checked 20 August 2026. Everything about that job, including the sizes above and below 3m by 3m and what pushes it up, is on conservatory roof replacement.

So: one leak, one joint, a roof with years in it, repair it. Repeat leaks in different places, a roof over fifteen years old, or a room you already avoid using in winter, and the repair is a payment towards a decision you have already made. What that decision involves day by day, from scaffold to sign-off, is the fitting process.