Replacing a conservatory roof looks quick from the garden, because the old roof comes off and the new one goes on. Behind that sit several decisions that have to be made in the right order: what the frame can carry, which system suits the room, how the new roof meets the house wall, and what happens if it rains while the roof is open. This guide follows a typical conservatory roof installation from the first visit to the final inspection, so you know what is happening on your property and why each stage comes before the next. Your own job may vary with the system you choose, and we explain where it does.
The survey comes first, and it is free
Every job starts with a visit. We look at the roof from the garden, from a ladder and, where the house allows it, from the bedroom window above. We check the state of the frame (uPVC, timber or aluminium), the eaves beam that carries the roof around the edge, the cill and the base walls, and the junction where the conservatory roof meets the house. We look for cracked glazing bars, failed gaskets, slipped panels and stained plasterwork inside the house wall, because those marks tell us whether water is coming through the roof or through the wall.
We take photographs of what we find, so the report you receive shows your own conservatory rather than a stock diagram. Measurements follow: the span, the pitch, the height of the eaves and the rafter length. If you are moving from a translucent roof to a solid one, the survey also feeds the frame check, which is covered properly in our guide on the frame and foundation checks for a solid roof. Sometimes the survey shows the roof is repairable, and we say so. A failed seal or a few cracked panels can be put right without a new roof, and a new roof is not the only answer on every property.
After the survey you get a fixed written quote. It names the system, the work included and the work excluded, so there are no surprises when the access equipment goes up.
Choosing the system before anyone orders anything
The installation process differs depending on what is going on top, so the system is settled at quote stage. There are three broad routes. A polycarbonate roof is a lightweight sheet system, the quickest to fit. A glass roof is heavier and needs a firm frame, with glazing bars that carry the panes. A solid roof, usually a lightweight tile system, replaces the glazing with an insulated, tiled structure and a plastered ceiling inside. If you are still weighing these up, our comparison of glass, polycarbonate or solid conservatory roofs sets out the differences, and lightweight tiled roof systems explains what a tiled system is made of.
The rest of this guide describes a solid tiled roof, because it has the most stages. For glass and polycarbonate the sequence is shorter, and we note the differences as we go.
Paperwork: building control before the first tile
Replacing a translucent roof with a solid one needs a Building Regulations application, because the frame and foundations must be able to take the extra load. Building control checks that. We handle the Building Regulations side where work is notifiable, so you are not left filling in forms. The details of what is assessed are in our guide to conservatory roofs and Building Regulations, and whether planning rules come into it is covered in the planning permission guide.
A registered building control approver, or the council's own building control team, will usually want to see the system details, the structural information on the frame and the proposed fixings. They may inspect at set stages, for example after the roof structure is in place and before the ceiling is closed up, which is why we do not rush through those stages. Using an assured or registered roof system can speed the approval, but it does not remove the need for it.
A listed house, or one inside a conservation area, calls for a word with the council's conservation officer about any change of material or appearance before it is agreed.
Access, scaffolding and protecting the house
Before the strip-out begins, the site is prepared. Furniture and fragile items come out of the conservatory, or are covered and moved to the centre of the room. Floors are protected with dust sheets and boards. Plants are moved out of the way, and we agree where skips, materials and the ladder or scaffold go. A low, single-storey conservatory can often be reached with a podium or a tower, while a conservatory beneath a first-floor window may need scaffolding to give safe access and an edge-protected working platform. Safe access matters more than speed, because old glazing is brittle and heavy.
The setting matters as well. The neighbour's fence, the line of the gutter and the route from the front of the house to the back all affect where we work from and where the skip sits. We also check the eaves for nesting birds before work starts, as nesting birds and bats are protected and the work may need timing around them.
Stripping the old roof
Strip-out is the noisiest part of the job and also the most revealing. Polycarbonate sheets are unscrewed and lifted off, glazing bars are detached, and glass panes are taken out one at a time, carried down and stacked for removal. The old ridge, any cresting and the gutter brackets are removed. Cheap or poorly fitted roofs sometimes reveal rot in a timber wall plate, a corroded steel section inside a bar, or a gap where the original builder stopped short of the house wall. That is the stage at which hidden problems appear, and where we stop, show you the photograph and agree the next step before we carry on.
We keep the opening protected as we go. Sections are removed and the exposed area is covered with sheeting, so a sudden shower does not soak the room or the plaster on the house wall. On a bigger roof we strip and make safe in stages rather than opening the whole thing at once.
Checking and preparing the frame
With the roof off, the frame can be inspected in full for the first time. We look at the eaves beam and the tops of the frame to see whether they are straight, level and sound. A conservatory that has been roofed with lightweight polycarbonate for years may have a frame that was never designed for the weight of tiles, and that is why the survey and building control input come first. If the frame passes, the next step is to fit a new perimeter structure. For a tiled system that is normally a ring beam or a timber or steel wall plate bolted along the top of the frame, spreading the load of the new roof evenly down onto the base walls and foundations rather than letting it sit on the window frames themselves.
If the frame does not pass, we tell you before any new roof materials are ordered. Reinforcing a frame is a separate piece of work, and it needs to be priced and agreed on its own terms.
Building the new roof
Construction then proceeds from the outside in. Where a solid roof is used, the main elements go in roughly this order:
- A fixed wall plate along the top of the frame and the ridge or a supporting beam at the apex, tied back to the house.
- Rafters or a prefabricated lightweight frame, set to the pitch agreed at survey.
- A breathable membrane and, where the system calls for it, rigid insulation fitted between or over the rafters.
- Battens (the timber strips the tiles hook onto), then the lightweight tiles, fixed to the manufacturer's specification.
- Ridge components, mechanically fixed, because mortar alone is not relied on for ridge, hip and verge fixings.
Lightweight tiles are laid much like ordinary tiles, course by course from the eaves upwards, with the pattern kept straight and the gaps consistent. Verges, hips and valleys are finished with the system's own trims, and each junction is detailed so water runs over it rather than behind it. For a lean-to roof that means a single slope with a flashing at the top; for a Victorian or Edwardian style, hips and a ridge finial add more detail. Our page on tiled conservatory roofs shows what these finished roofs look like and how they are put together.
Glass and polycarbonate replacements skip most of this. The new glazing bars go on, seals and gaskets are fitted, glass or sheets are set into them and the ridge and trims close the top. The work is quicker because there is no insulation layer, no battens and no tiles, and no internal ceiling to form.
The house-wall junction: where roofs usually fail
Where the conservatory roof meets the house is the detail that needs the most care. A flashing is a strip of metal, normally lead, dressed over the top edge of the roof covering and tucked into the brickwork, so water cannot run behind the roof. We cut a groove into the mortar course (a chase), fit the lead into it, seal it and then dress it down over the tiles or glazing. On older houses the wall may be soft or rendered, which affects how the flashing is held.
A weak or missing flashing is the usual cause of the staining you see on the house wall inside, and our guide on leaking conservatory roofs goes into the causes. On a new roof, we get this right once, at the stage when everything is open and visible. After the flashing is in, the gutter is refitted or replaced, with its fall set so water drains to the downpipe rather than ponding.
Insulating and finishing inside
On a solid roof the inside of the room is finished after the weathertight shell is complete. Insulation is installed to the specification agreed with building control, and a plasterboard ceiling is fixed and skimmed. Spotlights or a ceiling light can be wired in by a qualified electrician at this stage, and any ventilation the system requires is built in. Plastering needs time to dry before it can be painted, so decoration is usually left to you or to a decorator once the plaster has cured.
The result is a room that behaves differently, because it no longer swings between greenhouse and cold store. If your conservatory has been too hot or too cold, you can read more in the guide on fixing a conservatory that is too hot or too cold.
Weather, timing and how long it takes
Weather is the single biggest variable in the programme. We do not open a roof when rain is forecast, and a stage is only started when it can be made watertight before we leave. A wet spell can push a start date back by days, and on a cold day some adhesives and sealants will not cure properly. The length of the job itself depends on the size of the roof, the system and how much repair the frame needs. Our page on how long it takes to replace a conservatory roof deals with that question directly, and we give a realistic programme in your quote.
Sign-off, clear-up and the guarantee
When the roof is complete, we check every junction, test the gutters, and walk round the outside and inside with you. If building control is involved, the final inspection is arranged and the certificate follows once they are satisfied. The old panels and glazing leave with us, along with every offcut, and the garden is tidied before we go.
Our written guarantee on the workmanship runs for 10 years. You also get the photographs we took at each stage, which are useful if you sell the house later. We explain how a new roof affects a sale in our guide on conservatory roofs and selling your house. The free survey is booked on 01256 213956 or by WhatsApp. Our conservatory roof replacement in Basingstoke page covers the rest of what we do.
