Most rooflight problems start with a decision made months before anyone climbed a ladder: the wrong product for the room, an upstand specified at 100mm because the brochure said it was acceptable, clear glass on a south-facing lantern, a flashing kit that does not match the roof covering. By the time those show up as a stain on a ceiling, they are expensive.

So we write the guides we would want if we were buying. Real numbers, named regulations, and the trade-offs stated rather than glossed. If a guide talks you out of the more expensive product, it has done its job.

Technical drawings and a rooflight upstand cross-section on a workbench in flat overcast daylight from a window — Written from the roof, not from a brochure.

How the library is organised

Guides sit underneath the service they belong to. Each of the seven main services carries its own cluster of technical articles and direct answers to specific questions, so if you are looking into flat roof rooflights you are not wading through loft conversion content to find it.

Roof lantern guides

Kerb construction and why 150mm is a minimum rather than a target. Ring beams, trimmers and the point where a structural engineer is not optional. Aluminium against timber against uPVC. Glazing bar counts and proportion against room size. Lantern or flat rooflight, which is the question behind about half the enquiries we take.

Flat roof rooflight guides

Falls, ponding and why water sitting against an upstand is the beginning of every failure. EPDM, GRP, single-ply and felt junction details. Walk-on and flush-glazed units, what they genuinely cost and where they are worth it. Retrofitting into an existing flat roof that was never designed with a hole in it.

Pitched roof skylight guides

Flashing kits matched to covering type, which is the single most common cause of a leaking roof window in this region given how much deep-profile pantile Suffolk carries. Rafter trimming and load transfer. Sizing for Part B fire egress on loft conversions. Positioning for daylight, headroom and the view from a standing position rather than a lying-down one.

VELUX and roof window guides

Size codes decoded. Centre-pivot against top-hung and which suits a low sill. Replacing a unit from the mid-2000s with a current one, including what does and does not carry over. Blinds, flashing recodes and the honest position on installer certification.

Electric and opening rooflight guides

Chain against rack actuators. Rain sensor positioning, and why one fitted in the wrong place closes your rooflight every time the neighbour waters the garden. Solar-powered kits where a cable run is genuinely impractical. Wiring, isolation and what an electrician needs to do.

Energy efficiency guides

U-values, g-values and light transmission, and how those three numbers pull against each other. Part L thresholds for replacement and new work. Warm-edge spacers and thermal breaks. Cold bridging at the upstand, which is the reason a lot of “leaks” reported in January are actually condensation.

Commercial rooflight guides

GRP sheet replacement and barrel vaults. ACR[M]001 non-fragility classification and what it means for anyone stepping on that roof. Phased replacement on an operating building. Industrial estate and port-side work around Ipswich, Felixstowe and Harwich.

Close-up of a sealed glazing unit edge showing the warm-edge spacer bar, photographed in flat grey overcast daylight — Warm-edge spacer detail. The guides go to this level because the differences live here.

Three guides worth reading before you buy anything

Upstand height and fall. If a rooflight is going to leak, this is where. Not the glass, not the gaskets, and no amount of sealant fixes a detail that depends on sealant.
Glazing specification for orientation. Get the g-value wrong on a south-facing unit and you have bought a beautiful heat lamp. This one is cheap to get right at order stage and impossible to fix afterwards.
Coastal specification. If you are within a mile of open sea anywhere between Southwold and the Blackwater, standard fixings will let you down years early, and it is the least-discussed problem in this market.

Costs, honestly

The guides are technical. If you want figures, the costs page publishes real 2026 ranges by size and type for every service, plus every variable that moves a price: access and scaffolding, structural work, covering type, glazing specification and making good. No Suffolk competitor publishes prices at all, so it is worth an hour of your time even if you end up buying from somebody else.

Questions rather than guides

If you have one specific thing you want answered, planning permission, how long the roof stays open, whether a repair is possible, the FAQ page covers the fifteen or so questions we get asked most, with straight answers.

Still adding to this

The library is growing. Guides go up as they are written properly, which means when we have something worth saying rather than to fill a schedule. If there is a question you cannot find an answer to anywhere, ask us through the quote form and if it is a good question it will probably end up here.

When you are ready for a real figure on a real roof, request a fixed quote. We survey, price once, and hold that price.

Skip the reading

Rather just get a price?

If you already know roughly what you want, tell us about the roof and we will give you a fixed quote after a survey. No obligation, and a leaking rooflight gets prioritised.

Get a fixed quote See costs

Get a fixed quote

Tell us about the roof. We will tell you the price.

A survey costs you nothing and there is no obligation attached to it. We look at the roof build-up, the exposure and the opening, and give you one fixed figure, not an estimate that moves once work starts.

If your rooflight is leaking now, say so and we will prioritise the survey.

Fixed price, confirmed in writing
10-year workmanship guarantee
Installed to current Building Regulations
Your roof is never left open overnight