Skylight Installation in Holbrook
- Fixed quote before we start
- Roof never left open overnight
- 10-year workmanship guarantee
- Fixed quote before we start
- 10 years workmanship guarantee
- 25 years fitting rooflights
- Skylights only, not a general roofer
Holbrook sits on the Shotley peninsula with the land dropping away towards the Stour. Village stock, a fair amount of twentieth-century infill, and a lot of houses that have gained a rear extension at some point in the last forty years. That last group is where most of our work here comes from, and flat-roof extensions bring a specific problem with them.
Under seven miles from Ipswich, about twenty minutes down the B1080. An easy run, and the roads on the peninsula take a scaffold lorry without drama.
Ponding is what kills flat-roof rooflights
A flat roof is not flat. It is supposed to have a fall, and the usual design minimum is 1 in 80 after allowing for deflection, which in practice means designing to 1 in 40 so you still have 1 in 80 once the joists have settled under load. Plenty of older extension roofs around here have less than that, or had it once and lost it as the timbers sagged.
Water that does not run off sits. A pond on a flat roof is not immediately a leak, but it is a permanent test of every joint in the covering, and it puts the rooflight kerb in standing water for days at a time. Every freeze and thaw works at the junction. Sooner or later the weakest lap gives.
So before anyone discusses glass, we get a level on the deck and find out what fall exists. It takes ten minutes and it decides the whole specification.
Three outcomes, and they cost different amounts
- The fall is adequate. Straightforward. Build the kerb, dress the membrane up and over it, and set the unit. A normal flat roof skylight installation.
- The fall is marginal. We raise the kerb higher than the standard 150mm upstand so the glass edge sits well clear of any water that does linger, and we position the unit at the high end of the deck rather than the low end. Cheap insurance.
- There is no usable fall. The honest answer is that the roof needs firrings or a tapered insulation scheme to create one before a rooflight goes in. Fitting glass into a deck that ponds is putting a good unit into a bad roof, and it will be blamed on the rooflight when it fails.
We tell you which of those three you have got at survey, in writing, with the cost consequence. It is the difference between a quote you can trust and a number that changes once someone is on the roof.
Upstand height is not a detail to trim
The kerb carries the rooflight above the water line. Standard guidance for a flat roof upstand is a minimum of 150mm from the finished roof surface to the top of the kerb. On a roof with marginal fall, or one that gets driven rain across it from the Stour side, more is better. Cutting the upstand down to make a rooflight look lower is a false economy that gets paid for in about year four.
The membrane, whether it is single ply, felt or GRP, is carried continuously up the face of the kerb and over the top edge before the unit is bedded. The waterproofing is the membrane, not the sealant under the frame. Sealant is a secondary line, and treating it as the primary one is the most common reason a flat-roof rooflight leaks.
Estuarine exposure on the Stour side
Holbrook faces the tidal Stour. That means saline water and wind coming across a wide open channel, with moderate salt loading rather than the full open-sea conditions you get out towards Harwich or Felixstowe. Practically, we upgrade fixings to stainless on exposed elevations and pay attention to the finish on any exposed metalwork. It is a sensible precaution, not a marine specification.
What else we fit in Holbrook
- Roof lantern installation on wider rear extensions, where the room is big enough that a single flat rooflight would look mean and a lantern gives height as well as light.
- Pitched roof skylight installation on the main house slopes, including loft conversions.
- Energy efficient skylight installation where a big glazed area in an extension needs to hit Part L without turning the room into a greenhouse in July.
On lanterns versus flat rooflights: a lantern is a pitched structure sitting on a kerb, so it sheds water by its own geometry regardless of what the deck is doing. On an extension with a lazy fall, that is a genuine technical argument for a lantern rather than a styling preference.
Reading the deck: what a ten-minute level tells us
Putting a level across an extension deck does more than confirm the fall. It tells us where the water is going and what shape the roof is in underneath. A deck that dips in the middle rather than falling to one edge points at joists that have sagged under load or, on an older extension, timber that has softened where water has sat. Where we find that, we probe rather than assume, because a rooflight kerb fixed into a rotten deck edge has nothing sound to hold it. We also check the outlets and the covering. A blocked or badly placed outlet is often the real reason a roof ponds, and the age and type of the existing covering, felt, single ply or GRP, decides whether it can be dressed into a new kerb or whether it is near the end of its life and worth renewing while the roof is open.
All of that comes back in writing with the quote, so if the honest answer is that the deck needs a tapered scheme or a re-cover before a rooflight is worth fitting, you can see the reason and the cost rather than discovering it once someone is up there.
The main-house roofs, and loft conversions on the peninsula
Not everything here is a flat-roofed extension. The village carries a mix of older cottages on hand-cut roofs and later twentieth-century houses on trussed rafters, and the loft-conversion enquiries turn on which one you have. A hand-cut roof can be trimmed and opened up for a generous rooflight, while a trussed roof takes a unit between the trusses without structural work or a designed detail if you want it wider. We establish which from inside the roof space, because from the garden the two look identical, and the answer sets both what is possible and what it costs. A converted loft also brings Part L for the new opening and Part B fire escape into the picture, and both are settled at survey.
Garage conversions and garden rooms
Alongside the rear extensions, a fair amount of Holbrook work is turning a garage or building a garden room into usable space, and a rooflight is often what makes the room work. These jobs bring their own quirks. A garage roof was built to keep a car dry, not to insulate a habitable room, so the covering, the fall and the insulation usually all need attention before a rooflight goes in, and the Part L standard for the new room applies to the glazing. A garden room is new construction, which is simpler, but the roof is often a shallow single-ply or GRP deck where the fall and the kerb height matter exactly as they do on an extension. On both, a flush flat rooflight suits a modest room while a lantern gives height and light to a larger one, and the choice is as much about the deck and the ceiling as about looks. We survey the actual structure and the fall rather than assuming a garage or a garden-room roof is ready for glass, because more often than not it wants some work first, and it is better to know that in the quote.
Getting a price in Holbrook
Surveyed on the roof, priced once in writing, fixed unless you change the specification. Ten-year workmanship guarantee and installation to current Building Regulations. We install and replace, and we do not offer patching, because a patched flat-roof detail buys a season and costs the same again afterwards.
We cover the peninsula at Chelmondiston, Stutton and Shotley Gate. The rest of the coverage is on areas we cover.
Request a fixed quote. If the job is a flat-roof extension, tell us roughly when the roof was built and what the covering is, and we can narrow the answer before we visit.
Our Holbrook extension roof holds water after rain. Can we still have a rooflight?
Not sensibly, until the fall is corrected. Standing water is a permanent test of every joint, and it puts the rooflight kerb in a pond for days at a time. The fix is firrings or a tapered insulation scheme to give a proper fall, usually designed to 1 in 40 so it still achieves 1 in 80 after the joists deflect. We check the fall with a level at survey and quote the honest answer rather than fitting glass into a roof that will fail around it.
How high does the kerb need to be?
A minimum 150mm upstand from the finished roof surface to the top of the kerb is the normal standard. On a roof with marginal fall, or an elevation exposed to driven rain off the Stour, we go higher. The membrane is then carried continuously up the face of the kerb and over the top edge, so the waterproofing is the membrane rather than a bead of sealant under the frame.
Is Holbrook exposed enough to need marine fixings?
It is estuarine rather than open coast. The Stour is tidal saline water and the wind crosses a wide channel, so salt loading is moderate. We upgrade to stainless fixings on exposed elevations and check the finish on exposed metalwork. Full marine 316L and marine coatings belong on genuinely open-coast addresses, and specifying them here would be charging for something the site does not need.
Would a lantern or a flat rooflight suit our extension better?
It depends on the deck and the room. A lantern is a pitched structure on a kerb, so it sheds water by its own shape whatever the deck is doing, which is a real advantage on a roof with a lazy fall. It also gives ceiling height and works better over a large open room. A flush flat rooflight is neater, cheaper and better where the room is modest or the sightline from an upstairs window matters.
Our extension roof dips in the middle. Is that just the fall, or a problem?
It is worth looking at closely. A deck that dips centrally rather than falling to an edge often means the joists have sagged or the timber has softened where water has sat, and a rooflight kerb needs sound deck to fix into. At survey we probe the deck, check the outlets and identify the covering, because a blocked outlet is frequently the real cause of ponding and the fix may be drainage and a corrected fall rather than the rooflight itself.
We want to convert the loft in the main house. Trussed or hand-cut, does it matter?
It decides the job. A hand-cut roof, common on the older village cottages, can be trimmed to open up a wider rooflight. A trussed roof, common on the later houses, takes a unit between the trusses without structural work, or needs a designed detail if you want it wider. We check which you have from inside the roof space, since they look the same from outside, and a converted loft also brings Part L and Part B fire escape into the specification.
Can you renew the flat roof covering at the same time as fitting the rooflight?
Where the existing covering is near the end of its life, doing both together makes sense, because the roof is open and the new membrane can be dressed cleanly up and over the rooflight kerb as one continuous waterproof layer. If the covering has years left we dress the rooflight into it instead. We tell you which at survey based on the type and condition of what is there, so you are choosing on the facts rather than being sold a re-cover you do not need.
Thinking about this job? We survey across Ipswich, Suffolk and north Essex and give you a fixed price before any work starts, with a 10-year workmanship guarantee.