Tiled conservatory roofs: what they cost and when they are worth it

A conservatory with a polycarbonate or glass roof has two settings. From about May it is unusable by mid morning. From October it is cold enough that you shut the door on it and stop counting it as part of the house. In between there is about six good weeks, usually in spring, and heavy rain is loud enough to stop a conversation at any time of year.

A tiled conservatory roof, which people also call a solid roof or a warm roof, is the fix for that. It is an insulated structure that replaces the transparent panels, so the room holds heat in winter and keeps it out in summer. Done properly you get a room. Done badly, or done on the wrong conservatory, you get an expensive roof sitting on frames that were never designed to hold it.

What it costs

Almost nobody in this trade puts a figure on their website, which is why the only number most people find is a directory average. Checkatrade publishes a Leeds range of £5,203 to £10,034 for conservatory roof conversions, averaging £7,209. That is the number Google puts in front of people before they reach any roofer, so it is a sensible place to start.

It is not a quote. What moves it:

• Size and shape. A three metre lean-to off a semi and a five metre Victorian-style roof with hips and valleys are different jobs. The shape matters more than the floor area, because every hip and valley is a junction that has to be formed and made watertight.
• What is up there now. Polycarbonate comes off in an afternoon. Sealed glass units are heavy, slow, and need care getting down safely.
• Whether the frames carry it. Sound uPVC in good order usually takes a solid roof as it is. Frames that have dropped need work first, and that is where a cheap quote turns expensive.
• The finish inside. Plastered and skimmed ready to decorate costs more than a panelled ceiling. Spotlights, a roof window or a vaulted finish move it again.
• Access. A conservatory you can walk scaffold and materials up to is cheaper than one behind a locked ginnel or up a steep garden.

The question to ask before you ring anybody

Not “how much”, but “will my frames take it”.

A solid roof is substantially heavier than polycarbonate. The frames and the base underneath were specified for the roof that is on there now, not the one you are thinking about. Any roofer worth using checks that before quoting, and tells you if the answer is no.

Here is how to make a start yourself. Stand inside and look along the top of the frames where they meet the roof. If the line is straight, that is a good sign. If it dips in the middle of a run, or the doors have started catching, or there is a crack running through the base slab outside, the structure has already moved and putting more weight on it is the wrong direction.

The other thing worth checking is the wall plate, which is the timber or aluminium the roof sits on where the conservatory meets the house. If that is rotten or pulling away, it has to be dealt with regardless of what goes on top.

When it is not worth doing

I would rather say this at the quote than halfway through the job.

If the frames have dropped or the base has moved, a new roof is money going onto a structure that needs redoing anyway. That is a rebuild conversation, and a rebuild with a proper insulated roof from the start is often better value than a roof conversion followed by a rebuild three years later.

If the conservatory was badly built to begin with, which around Leeds usually means one of the very cheap installations that went up in the mid 2000s, the same applies. You can tell by the frame thickness and whether there is any steel reinforcement in the uprights.

If you do not actually want the room, a tiled conservatory roof will not make you want it. It is a lot of money to spend on a space you walk through to get to the garden. Blinds and a decent electric heater cost a fraction and solve the problem for some people entirely.

If you were hoping it would be quick, be realistic. It is usually four to seven days depending on size and finish, and for part of that the room is open to the weather under temporary cover.

Where the Leeds conservatories are, and how old

The boom that put most of these on the back of houses ran through the late nineties and 2000s, which lands them on the estates built or extended in that window: Alwoodley, Cookridge, Holt Park, Whinmoor, Swarcliffe, Rothwell, Garforth and out towards Wetherby. Twenty-odd years on is exactly the age at which polycarbonate goes cloudy and green and sealed units start misting between the panes. That is why the calls cluster there.

Closer in, on the Victorian housing through Chapel Allerton, Headingley and Roundhay, the same problem arrives in a different shape: a glass lean-to on the back of a terrace or villa. Those are usually smaller and often taller, and the junction with a three storey rear wall matters more than the roof panel does. Getting the abutment flashing right on one of those is most of the job.

Building regulations, which people are not told about

Putting a solid roof on a conservatory is building work, and it normally needs building regulations approval covering structure, thermal performance, and how the room is separated from the house.

This matters years later rather than now. When you sell, a solicitor acting for your buyer asks for the paperwork. If there is none, you are looking at a regularisation application or an indemnity policy, and either is a nuisance in the middle of a sale.

A firm that tells you it needs no approval at all is telling you something useful about the firm. Ask the question early and see what you get back.

Glass, polycarbonate, or tiled

To be fair to the alternatives, because a tiled conservatory roof is not the only option:

Modern glass with a solar control coating is a genuine improvement on twenty year old glass, and it keeps the light. It costs about the same as a solid roof and it does less for the winter half of the problem.

New polycarbonate is the cheap option and it fixes the appearance rather than the temperature. If the panels have gone green and cloudy and you are otherwise happy with the room, it is a legitimate choice and nobody should talk you out of it.

A tiled roof with a roof window or two is the middle ground most people land on. You get the insulation and you keep some of the light, and it deals with the complaint that a solid roof makes the room feel like a shed on the back of the house.

What I would tell a neighbour

If the frames are sound, the base is sound, and you want to use the room all year, a tiled conservatory roof is one of the better value things you can do to a house. It is cheaper than an extension by a long way and it converts a space you already own into a space you actually use.

If any part of the structure has moved, or you are doing it because a salesman told you the room would be transformed, take a breath. The roof is not the expensive mistake. The expensive mistake is putting a good roof on a bad conservatory.