20 questions to ask a conservatory roof installer

The questions that matter most are who makes the roof, how the installer checked that your conservatory can carry it, who handles building control, what the roof’s U-value and guarantees are, and how much you have to pay upfront. A good installer answers all of them without hesitation and puts the answers in writing. The 20 questions below are grouped by stage, with why each one matters and what a good answer looks like.

The roof and who makes it

1. Which roof system is it, and who makes it? Many solid roofs are branded systems, such as Guardian Warm Roof, Ultraframe LivinRoof or Ultraroof, SupaLite, Leka or Eurocell Equinox. Knowing the system lets you read the maker’s installation guide, certificate and guarantee, and our brand reviews summarise each. A good answer names the system and the maker; a vague “our own lightweight roof” deserves a follow-up question.

2. Are you approved by that manufacturer? Guarantees often depend on it. Guardian’s consumer promise only applies to roofs fitted by Guardian Certified Installers, and SupaLite sells through approved independent installers. Ask for proof and check with the maker directly.

3. Is the system covered by an LABC Registered Detail or a type approval, and is the certificate current? These speed up building control but do not replace it; the LivinRoof certificate says it is “designed to fast-track, not remove” the need for approval. The copy of that certificate online shows a validity date of July 2022, so ask for the current one. If a BBA certificate is quoted, note that the BBA’s own site said in September 2026 that its UKAS accreditations were temporarily suspended.

The survey and the structure

4. How did you check my frames for steel reinforcement? A solid roof needs steel in the upright frames to carry the load to the floor slab. LABC suggests a magnet test or small pilot holes. A good answer describes the test and what it found. Our guide to whether your conservatory can take a solid roof explains what happens if the steel is missing.

5. Will you dig a trial hole or check the foundations another way? LABC expects trial holes in most cases, though they may not be needed where the added load is small, typically under 15%. Ask who digs it and who pays if the foundations need work.

6. Are structural posts, tie bars, box gutter supports or new windows needed, and are they in the price? These are the common extras. Price guides put steel reinforcement or structural upgrades at £800 to £4,000 when needed. Ultraframe says that if tie bars are specified, they must be fitted.

7. What happens to my side windows, doors and bi-folds? Several systems remove the glass from the frame heads to fix the new ring beam through them. The LivinRoof certificate says bi-folding doors under the roof must be bottom supported, not top hung, and Guardian notes that its box gutter insulation sits 82mm below the aluminium, so clearance for opening windows and doors must be allowed for.

8. What happens if you find a problem once the roof is off? Out-of-plumb walls, missing steel and poor foundations sometimes only show once the old roof is stripped. Ask how extra work is priced and agreed, and get it in the contract. Suffolk Trading Standards reported a cold caller’s roof repair quote rising from £2,000 to £29,900, which is the extreme version of what an open-ended contract allows.

Building control and paperwork

9. Who submits the building control application, to which body, and when will I get the completion certificate? A solid roof needs approval from your council’s building control or a registered building control approver. GOV.UK says a completion certificate usually arrives within 8 weeks of the work being finished. LABC stresses that compliance is ultimately the owner’s responsibility, so ask for the application reference before work starts. Council fees for a conservatory re-roof vary: Rotherham charges £480, for example.

10. Will the house stay thermally separated, and are you extending any heating? In England a conservatory only stays exempt from the energy rules if external-quality doors separate it from the house and the house’s heating is not extended into it. Removing the doors or adding a radiator on the central heating changes what the roof has to meet.

11. Who does the electrics, and will I get a certificate? Spotlights in the new ceiling are electrical work, and LABC asks for certification to BS 7671. A good answer names a registered electrician and confirms you will receive the certificate, which building control does not keep a copy of.

The specification

12. What is the insulation build-up and U-value, in writing? A new solid roof must reach 0.15 in England, 0.13 in Wales and 0.12 in Scotland. Get the figure and the insulation type and thickness in writing: building control needs them, and so will an energy assessor when you sell.

13. How do you control condensation? Warm roofs rely on foil-backed insulation, taped joints and ventilation. SupaLite recommends trickle vents around the window frames and air bricks in dwarf walls, and the LivinRoof certificate asks for ventilation that keeps relative humidity below 80%. A good answer is specific.

14. What does the internal finish include? Plasterboard type, skim coat and whether decoration is included. Solid roofs usually finish with a skimmed ceiling ready to paint, and painting is often left to you unless the quote says otherwise.

15. Are scaffolding, the skip, removal of the old roof and making good included? MyJobQuote lists scaffolding (£400 to £800), skip hire (£120 to £300), new guttering (£150 to £500), internal finishing (£500 to £2,000) and building control fees (about £200 to £400) as common extras.

Money and protection

16. What guarantees do I get, who issues each one, and are they insurance-backed? Expect a product guarantee from the maker and a workmanship guarantee from the installer; Which? advises at least 10 years. Ask whether an insurance-backed guarantee stands behind the workmanship if the installer stops trading, and how long that cover lasts. Our guide to guarantees explains the differences.

17. How much deposit do you need, and when are the stage payments? Citizens Advice advises a deposit of no more than 25%, paid by card, with the rest in stages. DGCOS deposit protection, for example, does not cover deposits above 25% of the contract value. A credit card adds Section 75 protection on purchases over £100 and up to £30,000.

18. Is this a fixed quote or an estimate? Citizens Advice warns that an estimate, unlike a quote, can leave you liable for extra charges. Ask for a fixed price for the agreed specification.

19. Which trade body or scheme are you in? Which? points to membership of the Glass and Glazing Federation, FENSA registration and Which? Trusted Trader as things to look for. Check membership with the scheme itself: displaying a trust mark without authorisation is banned under the Digital Markets, Competition and Consumers Act 2024. FENSA is a scheme for replacement windows and doors, so a FENSA certificate would not by itself cover a new solid roof.

The people and the timing

20. Do you use subcontractors, how long will you be on site, how many people, and will you make good afterwards? Which? suggests asking all of these. A good answer gives a named team, a realistic number of days and a clear plan for the garden, the skip and the mess.

How long does it take to replace a conservatory roof?

Solid roof makers quote 2 to 5 days on site: Guardian says its roof typically takes 2 to 3 days, Leka 2 to 3 days including removal, and ExpertSure reports 3 to 5 days for an Equinox roof on a standard Edwardian. A new polycarbonate roof can often be done in a day.

Plastering can add time, and one installer quotes 4 to 6 weeks from quote to start. Our guide to what happens on installation day walks through the stages.

Answers that should make you walk away

• “You don’t need building regs for a tiled roof.” LABC says you do.
• “This price is only available today.” Falsely claiming an offer is time-limited to rush a decision is banned under the Digital Markets, Competition and Consumers Act 2024.
• Refusing to leave, or coming back when asked not to. Both are banned practices under the same Act.
• A deposit above 25%, or a request for cash. When Safestyle went into administration in 2023, customers who had paid cash deposits were told they would not be repaid.
• No written cancellation information. For a contract signed at home, you normally have 14 days to cancel, extended by up to 12 months if the trader failed to give you the cancellation information; not giving it is a criminal offence.
• Unnamed “grants” or “subsidies”. Ask for the scheme’s name in writing and check it yourself.

Turning the answers into a fair comparison

When you get quotes, put each installer’s answers side by side: the same roof system or an equivalent U-value, the same structural work, the same internal finish, the same electrical scope and the same building control route. A cheap quote often leaves one of these out. Our guides to comparing quotes like for like and red flags when buying take it from there.