Guardian Warm Roof review

A Guardian Warm Roof is a factory-made insulated roof with a lightweight aluminium frame and lightweight tiles or slates on top. It replaces the see-through roof on an existing conservatory, gives you a plastered ceiling inside, and turns a room that is too hot in summer and too cold in winter into one you can use all year.

Understand the supply chain before you buy. Guardian designs and licenses the system, fabricators make up each roof, and an independent Certified Installer sells and fits it. Your contract, workmanship guarantee and aftercare are with that installer, not with Guardian.

Who makes the Guardian Warm Roof?

Guardian began in Ireland, where Joe Kearney started fabricating roofs through his supplier business, Celuplast. Guardian’s brand history page says the company was founded in 1997 (a search summary of the same page gave 1995). Celuplast is still “the exclusive fabricator of all Guardian Building Systems products in Ireland”. According to a summary of the brand history page that we could not re-check, Double R became the first UK fabricator in 2008, followed by an exclusive partnership with the tile maker Metrotile.

Guardian describes itself as “the original and most trusted solid roof system in the UK”, says it has been “approved by Building Control since 2006”, and claims more than 100,000 installations in the UK and Ireland. These are the company’s own claims.

The company behind the brand is less clear than for most rivals. Guardian’s privacy policy names Guardian Building Systems Ltd, but we could not find a UK company of that name on Companies House, so its UK company number is not confirmed. Earlier companies with Guardian in the name have closed: Guardian Warm Roof Limited (08391437, Stourbridge) was dormant and dissolved on 26 April 2022, and Guardian Warm Roof Holdings Limited was dissolved on 14 January 2025. Many small firms on the register also use “Guardian Warm Roof” in their names, and their link to the brand owner is not confirmed. Guardian Warm Roof has no connection with Guardian Glass, the glass maker.

How a Guardian roof is built

Guardian describes a prefabricated insulated warm roof on a lightweight, precision-engineered aluminium frame with integrated ventilation. The parts arrive on site in pre-cut sections numbered to match a layout plan. One installer publishes this build-up, from outside in:

1. Tile or slate finish
2. Breathable membrane
3. Exterior grade plywood deck
4. Two 50mm layers of high performance insulation
5. Timber battens
6. 72mm insulated plasterboard, ready to plaster

An older Guardian brochure shows thinner insulation (25mm plus 40mm), so the build-up has changed over time. Guardian’s installation guide insists that “all insulation used must have a foiled back covering”, that foil tape goes over every batten “so no timber will be visible from the inside”, and that tie bars are fitted before the internal fit-out. It also says the plan requires all the side windows to be fully reinforced, which is why your surveyor should check the frames. Guardian says a typical job takes 3 to 5 days depending on the design.

Guardian Warm Roof specifications

Specification	Guardian Warm Roof
U-value (maker’s figure)	0.15 W/m²K England, 0.13 Wales, 0.12 Scotland, “fully tested and BRE-assessed”. Older brochure: 0.18
Weight	Not published by Guardian. About 55 kg/m² according to ConservatoryRoofCosts.co.uk (third party)
Frame	Lightweight aluminium with integrated ventilation
Tile and slate finishes	Guardian Esprit Shingle, Metrotile Shingle, Guardian Slate; one supplier also lists Tapco Slate
Colours	Esprit: Greenstone, Coal-Black, Charcoal, Scarlet. Metrotile: Scarlett, Red-Brown, Ironbark, Forest Green, Coal Black, Brown-Black, Bistre-Brown. Slate: Black, Grey, Mulberry, Terracotta
Glazed options	Guardian Solstice Rooflight (a sealed glazed panel) and VELUX roof windows; installers also offer sun tunnels and LED spotlights
Ceiling	Insulated plasterboard, ready to plaster
Certification	LABC approved, HBC approved, BRE tested (including fire tests of the finishes), TrustMark Scheme Provider from 2025. An older brochure lists LABSS approval for Scotland. ExpertSure cites BBA certificate 13/5078; Guardian does not mention it and we could not verify it
Guarantee	10-year product guarantee plus 10-year workmanship guarantee from the Certified Installer, insurance-backed
Time on site	3 to 5 days (Guardian)

Guardian Warm Roof cost in 2026

Guardian does not publish prices, so every figure comes from third parties:

• ExpertSure (May 2026): £7,500 to £14,500 fitted, with most 14 to 18 m² Edwardian or Victorian roofs at £9,000 to £11,500. It does not say whether VAT is included.
• ConservatoryCost.com (June 2026): £900 to £1,400 per m² installed.
• Double Glazing Direct, an installer: from £5,000, rising to £15,000 for larger projects.

For context, our researched range for any tiled roof on a medium conservatory in the four common shapes is £7,400 to £12,100 fitted in 2026, typically about £9,600. ExpertSure’s Guardian figures start at the bottom of that band and run above it for larger roofs. Our tiled conservatory roof cost guide breaks prices down by size and style.

Guardian also cites modelling by AECOM that a Guardian roof saves “more than £200 per year on average”, or £5,447 over 25 years, for a 12ft by 12ft Victorian conservatory with electric heating. That was commissioned modelling, not measured bills, so treat it as a best case.

Who sells and fits Guardian roofs?

Guardian does not fit roofs itself. It supplies a UK-wide network of Certified Fabricators, who make up the roofs, and Certified Installers, who survey, sell and fit them. ExpertSure estimates about 70 approved installers across the UK and Ireland and calls it the largest approved installer network of the tiled systems it reviewed.

Installer quality is what varies. Individual firms trading on the Guardian name can score very differently from the brand: NECS Group, trading as Guardian Roofs UK, had 4.9 out of 5 from 101 Trustpilot reviews on 27 September 2026. Before you sign, check the firm’s Guardian certification, look up its own company number and history on Companies House, ask which insurer backs the guarantee and confirm who submits the building control application. Our list of questions to ask an installer covers the rest, and our building regulations guide explains why the completion certificate matters when you sell.

Reported problems and Trustpilot reviews

On 27 September 2026, Guardian Building Systems had 3.3 out of 5 from 21 Trustpilot reviews: 71% five-star and 24% one-star. The low-star reviews raise these themes:

• Installers going into liquidation, leaving customers without recourse or a usable guarantee, with Guardian saying responsibility lies with the installer.
• Building control certificates not obtained by the installer.
• Leaks, water staining and condensation appearing years after installation.
• Tile fading.

A separate, unclaimed “Guardian Warm Roof HQ” profile has 12 reviews, is closed to new reviews and cites refused guarantee claims and slow communication.

Keep the numbers in proportion: 21 reviews is a small sample against a claimed 100,000 installations, and most homeowners review their installer rather than the system maker. The pattern is still useful. The insurance-backed guarantee exists for exactly the case where an installer stops trading, so ask for the policy document and the insurer’s name at handover. If condensation worries you, our guide to conservatory condensation explains what to check.

Guardian vs LivinRoof, SupaLite and LEKA

	Guardian	LivinRoof	SupaLite	LEKA
U-value (maker)	0.15 (England)	0.15, or 0.12 option	0.15, or 0.12 enhanced	From 0.10
Weight	About 55 kg/m² (third party)	31 kg/m² (maker)	Under 46 kg/m² (maker)	About 34 kg/m² (third party)
Outside finish	Shingle or slate tiles	Grey insulated panels	Tiles or slate	Tiles or slate
Guarantee	10 years product, 10 years workmanship, insurance-backed	10-year parts	10 years (product page)	40-year components
Published price	£7,500 to £14,500	£9,500 to £15,500	From £10,000 plus VAT for 10 m²	None found
Installers	About 70 (ExpertSure)	About 35 (ExpertSure)	About 30 (ExpertSure)	350+ (LEKA claim)

Guardian’s strengths are its tile choice, lower U-values for Wales and Scotland and insurance-backed workmanship cover. LivinRoof is much lighter and takes glass almost anywhere; LEKA claims the lowest U-value and longest warranty. See Guardian vs LivinRoof, Guardian vs SupaLite and Guardian vs LEKA for the detail.

Verdict: who a Guardian roof suits

A Guardian roof suits you if you want a conventional tiled look with a real choice of shingle and slate finishes, a U-value that meets the England figure, and an installer network wide enough to get several quotes. If you want lots of glass, a lighter hybrid may fit better; see our overview of tiled conservatory roofs for the alternatives.

Because the installer carries so much of the risk, choose the firm as carefully as the roof. When you get quotes, ask each Guardian installer for the U-value in writing, the name of the guarantee insurer, proof of certification and a firm date for the building control completion certificate.