Condensation between panes and fogged-up glass can make your home feel cold, tired and inefficient, no matter how high you turn up the heating.
We replace failed or outdated glazing with energy-efficient double glazed units, made-to-measure and fitted by FENSA-registered installers, backed by a free home survey and a 10-year guarantee.
Our qualified glaziers use high-performance insulated glass, warm-edge spacers and secure locking systems to cut draughts, reduce noise from the street and help lower your heating bills.
Whether you’re dealing with blown units, faded uPVC frames or rotten timber sashes in your Manchester property, we’ll assess your windows, explain the options in plain language and give you a clear, itemised quote in £.
The following sections explain our installation process, product options and aftercare in more detail.
Takeaways
- Professionally cut and flashed openings take 24–28mm argon‑filled low‑E units, cutting heat loss and condensation risk.
- Certified glazing with warm‑edge spacers and continuous Q‑LON gaskets improves insulation, reducing heating bills and draught complaints.
- Multi‑point locking hardware and tested wind and water performance enhance security and weather resistance against forced entry or storms.
- Verified licences, public and employers’ liability insurance, plus FENSA/Certass registration protect you if anything goes wrong.
- Clear installation schedule with on‑site level, operation and draught checks keeps disruption predictable and handover straightforward.
- Written weatherproof warranty with response times, exclusions and FENSA certificate number supports resale value and future grant applications.
Do You Need Professional Skylight Installation?
Plenty of handy homeowners fit their own skylights, but on a lived-in roof it’s usually a job for a trained glazier or roofer. A professional will cut and trim the opening without weakening the rafters, then build and fix the upstand so it sits square and level, ready to take a 24–28mm argon-filled, low‑E double-glazed unit.
The detailing round a skylight is what stops leaks. Proper flashing in stepped courses with the existing tiles, correct overlap on the felt, and a continuous Q‑LON gasket on the frame all help keep out driven rain and draughts. Get the falls wrong on the lead or the tiles, and you’ll be chasing damp patches and blown plaster within a couple of winters.
A fitter who does this every day will check the roof pitch, loading, and ventilation in the room below, then size the skylight so you get useful light without overheating the space. On completion you should see:
- A-rated glass with warm-edge spacer bars
- Internally beaded frames and multi-point locking (for opening units)
- All external joints sealed and documented
- A FENSA certificate number on the paperwork to keep your warranty and future sale in order
If you want a skylight in, say, a tiled roof in Manchester to last, it’s cheaper in the long run to pay a pro once than to pay for a second job and making good after a DIY attempt goes wrong.
How Skylight Types Affect Performance and Weatherproofing
Having a pro fit your skylight cuts down the usual risks, but the unit you choose has just as much say in how it performs and stays watertight long term. You’re choosing between fixed or opening, tubular or flat glass, and each option changes how we flash it, seal it and service it.
Fixed skylights are the most reliable on weatherproofing because there are no hinges or moving gaskets to fatigue. A fixed, A-rated, 28mm argon-filled, low‑E double glazed unit with a continuous Q‑LON gasket around the frame will handle years of wind, rain and thermal movement with very little adjustment.
Opening skylights give you fresh air and help clear condensation, but the hardware and seals need more attention. On these we’ll use:
- High quality compression gaskets on the opening sash
- Proper stepped lead flashing or GRP kits matched to your roof covering
- Multi-point locking where the size allows, to keep the sash pulled tight on the seals
Tubular skylights suit tight areas like landings and internal bathrooms where a full window won’t fit. The reflective tube controls light spread so you don’t get harsh glare, and because the glazed roof unit is compact and factory‑sealed, heat loss and draught risk are lower than a larger opening frame.
Flat glass units and larger glass lanterns give you the most daylight and sky view. To keep them efficient in places like Manchester’s mixed weather, we specify laminated inner panes for safety, low‑E coatings and argon‑filled cavities to cut heat loss and reduce internal condensation on cold mornings.
Your choice of skylight dictates how complex the sealing is, how often we’ll expect to adjust hinges or locks, and how much movement from wind and temperature the installation will tolerate. Fitted correctly, with the right flashing system and a FENSA certificate issued on completion, a good unit should stay secure, draught‑free and watertight for many years.
Which Skylight Suits Your Roof and Climate?
Your roof shape, pitch and the local weather all affect which skylight will actually work and stay watertight. On low-pitch roofs we usually fit curb-mounted units with purpose-made flashing kits, so the upstand keeps the 28mm sealed unit clear of standing water. On steeper roofs we can use a wider range of deck-mounted or tile-flush skylights, fixed or opening, with code-matched flashings for slate or concrete tiles.
We match the glazing to the energy rating you need. An A-rated, argon-filled, low-E double or triple glazed unit will cut heat loss in colder, exposed spots, while solar-control glass helps in sunnier, south-facing roofs to limit overheating. Thermally broken aluminium or uPVC frames reduce cold bridging and condensation around the frame.
On coastal or high-wind sites we allow for higher wind load, extra fixings into the rafters and reinforced frames. In heavy snow areas or high moorland we check rafter sizes and centres so the skylight doesn’t overload the roof, and we detail the insulation and vapour barrier right up to the frame to avoid draughts. Opening skylights with secure, multi-point locking and trickle vents give you controlled ventilation without leaving the roof vulnerable.
A proper survey is essential. We measure the roof pitch, check rafter condition and spacing, confirm the build-up (cold or warm roof), and then specify the skylight, flashing kit and glazing. On completion you get a FENSA certificate, manufacturer warranty details and our installation notes so your roofer or builder knows exactly how it’s been put together.
How Installers Create a Weatherproof Seal (Flashing, Insulation, Ventilation)
On a double-glazed rooflight, the weatherproofing is only as good as the way the frame, glass and roof are tied together. We build the seal up in layers – proper flashing, tight insulation and controlled ventilation – so you’re not fighting leaks, cold spots or condensation a year down the line.
We use metal or moulded flashing kits that marry into your existing tiles or slates and any roofing membrane, then bed and seal them with compatible roofing sealant, not silicone out of a bathroom tube. The aim is to shed water in stages, so rain runs off the A-rated 28mm argon-filled unit, onto the frame, into the flashing, then onto the roof without pooling.
Around the frame, we pack insulation to cut down heat loss and stop cold bridging into the room below. That usually means mineral wool or PIR board tight to the curb, with a continuous vapour control layer taped to the existing roof membrane so warm, moist air from inside can’t creep into the roof void and condense on the frame.
We always keep ventilation paths in the roof space clear, especially at the eaves, so any moisture that does get in can escape instead of sitting on timbers and fixings. Done right, that protects the sealed unit, the Q-LON gaskets and the frame fixings, and helps your FENSA-certified installation keep its performance figures for the long term in Leeds or anywhere else.
Step‑By‑Step Skylight Installation Timeline
Before we take out your old frames, you’ll get a clear schedule showing each stage of the install – survey, removal, frame fixing, glazing, sealing, and final sign‑off – so you know who’s on site and what’s happening each day.
Day by day, you’ll see:
- Site protection and final measure‑up for made‑to‑measure frames
- Removal of existing units and prep of openings, including checking brickwork and cavities
- Fixing new uPVC or aluminium frames square and plumb, with frame packers and stainless steel fixings
- Dropping in 28mm argon‑filled, low‑E A‑rated sealed units, internally beaded for security
- Fitting Q‑LON gaskets, perimeter sealing, and making good inside and out
- Setting and testing multi‑point locking, trickle vents and fire‑escape hinges where required
At each stage we check frame level, operation, and draught‑proofing with a physical inspection, not just by eye. Before we leave, we run through window operation with you, hand over your FENSA certificate number and itemised guarantee, and confirm you’re happy with the finish.
Typical Costs, Value, and Warranty Impact
If you’re costing up new double glazing, the price comes down to size, spec of the sealed unit and how much work is needed to fit it into the existing opening. A standard UPVC casement with a 28mm argon-filled, A-rated unit and low-E coating will usually sit at the lower end, while larger openings, shaped frames or extra openers push the price up.
Installation is cheaper on straight swaps into sound frames than it is on jobs needing brickwork alterations, steel over-lintels or access towers. First-floor and above often need scaffold or a tower, which adds to the labour and any permit fees if we’re working over a public pavement.
Paying a bit more for insulated frames, warm-edge spacers and proper Q-LON gaskets reduces draughts and condensation, so you’re not paying twice in heating bills. Multi-point locking, internally beaded sashes and reinforced hinges also add to the cost but are what mortgage valuers and buyers now expect across places like Leeds.
Check what the warranty actually covers: a good setup is:
- 10 years on frames and sealed units against fogging
- Clear terms on hardware, usually 5 years on handles and locks
- FENSA certificate number on completion for Building Regulations sign-off
Factor in cleaning, hinge lubrication and the odd handle replacement over 10–20 years. If you compare quotes, line them up on like-for-like specs – glass rating, gasket type, locking points and warranty length – then choose a glazier who can show recent FENSA registrations and will put all of it in writing.
Questions to Ask a Skylight Installer
Before choosing an installer, it helps to understand the basics of competence, accountability and long-term support. Asking for proof of licensing and insurance protects you from liability if something goes wrong on site or with building regulations. Clarifying the installation schedule gives you realistic expectations about access, disruption and completion. It is also important to know exactly how warranties work, including weatherproofing and future issues with seals or flashings, as the following sections explore in more detail.
Licensing And Insurance
Skylight work means going through your roof structure, so you need an installer who’s properly covered and allowed to be up there. Before you sign anything, ask for written proof of their current glazing or building contractor licence and insurance. A decent firm will send over copies without fuss and put their FENSA or Certass details on the paperwork.
Make sure the contract spells out exactly what’s included: size and spec of the skylight, how the opening is trimmed and insulated, who’s handling Building Control, and what the warranty covers on the frame, A‑rated glass unit and any flashing kit. You want the terms in black and white, not a promise on the driveway.
Ask for copies of:
- Public liability insurance, with cover high enough for the value of your roof and interiors.
- Employers’ liability insurance, so any lads on the roof are covered if there’s an accident.
- The installer’s licence/registration and, if it’s window work as well, their FENSA/Certass details.
Check the liability limits on the insurance documents match or exceed the cost of your project and comply with local requirements. Keep digital and paper copies of all licences, insurance certificates and endorsements with your signed contract. If there’s a leak, broken tiles or a dispute over Building Regulations later on, you’ll have everything you need to get it put right.
Installation Timeline Expectations
On any double glazing job, you should have a clear written schedule before we start. We break the work down into stages – survey and measure-up for the made-to-measure units, removal of old frames, prep to brickwork, fitting the new A-rated 28mm argon-filled units, sealing inside and out with Q-LON gaskets and silicone, final trims, then sign-off and your FENSA certificate number.
Ask your glazier how long each stage usually takes on a property like yours, what access they need, and how they deal with rain, high winds or delayed deliveries. For a standard three-bed in Manchester, for example, we’ll agree start and finish dates, normal working hours on site, and which days are noisy or dusty so you can plan around them.
A decent schedule will also spell out:
- Which rooms are done on which days
- When old frames and glass are taken away
- When scaffolding or towers are going up and coming down
- When you’ll get your paperwork and guarantees
Having that detail in writing helps you protect carpets and furniture, keep neighbours informed, and know exactly when the last bead is clipped in and the multi-point locks are tested. A precise timetable shows the fitter is organised and has thought through the job properly.
Warranty And Weatherproofing
Weatherproofing & Warranty
Good-looking windows are no use if they let in water or draughts. Get everything in writing: how the frames are sealed, what’s covered, and how quickly they’ll be back if there’s a problem.
Ask for clear details on:
- Waterproofing: type of external sealant, how the cills are bedded, and the flashing detail if it’s a bay or roof area
- Gaskets: Q-LON or equivalent compression seals around the 28mm argon-filled, low‑E sealed units
- Weather performance: tested wind-load and water-tightness ratings for the profile being fitted
- Warranty terms: length of cover for frames, glass units, and hardware; labour included or not; any £ call-out charge; and if the warranty can be transferred if you sell
Get written timelines for any corrective work on leaks or failed units. Ask for:
- Recommended maintenance and simple seasonal checks to keep seals, hinges, and handles in good order
- Agreed inspection intervals on longer jobs and the response time if you report a leak or misted unit
- A clear list of exclusions, and how storm or impact damage is handled through their insurer or yours
You should leave the job with a concise warranty document, weatherproofing notes specific to your install, and the FENSA certificate number for your property in Manchester on completion. A glazier who knows their trade will have no problem putting all of that on paper.
Common Installation Problems and Fixes
If you want your new double glazing to last, most issues come down to how it’s fitted. Gaps around the frame are usually from rushing the packers or not squaring the opening properly. That’s what causes draughts and rattling. The fix is simple but precise: re-pack the frame so it’s plumb and level, then re-seal with a continuous bead of manufacturer-approved low-modulus silicone and fresh Q-LON gaskets.
Condensation between the panes points to a failed 28mm sealed unit, usually through poor handling or bedding. That unit needs replacing like-for-like with an argon-filled, low-E A-rated unit, properly toe-and-healed so the weight sits on the correct packers, not on the corners. Surface condensation on the inside is often down to poor room ventilation, not the glass, so trickle vents in the new frames and a quick check of existing extract fans usually sort it.
Incorrect frame height or twist in the opening can strain the hinges on an outward-opening casement. Over time that pulls the sash out of line and ruins the seal. We correct this by checking diagonals, adjusting or replacing friction stays, and tightening hardware to the manufacturer’s torque spec so the multi-point locking system pulls the sash in evenly all round.
Sealant spread thinly or missed entirely along the cill and head is a common cause of water ingress. The answer is to strip back to sound material, clean down the masonry, and apply a continuous external seal, making sure the cill nose projects enough to shed water clear of the brickwork. Internally beaded frames are then checked so the beads sit tight and the glazing tape is properly compressed.
On doors and larger windows, poor alignment of keeps on the frame can mean the multi-point lock never fully engages. That leaves you with a stiff handle, poor security and cold spots. We realign keeps, adjust the cams on the locking strip, and test closing pressure all round so the Q-LON gasket compresses correctly without you having to force the handle.
At the end, we check every opener, trickle vent and lock in front of you. Any replacements or new fits are logged with FENSA, and you get the certificate number on completion for your records in Leeds or for when you come to sell.
What a Weatherproof Guarantee Should Cover and How to Verify It
Fixing poor fit is only half the job. You also need a written weatherproof guarantee that spells out exactly what’s covered and how any call-backs are handled.
Read the guarantee and check it clearly lists:
- What’s covered: seals (for example Q-LON gaskets), cills, trims, flashing, glazing, frame joints and drainage holes.
- How long each part is covered: A-rated 28mm argon-filled units, low-E coated glass, hardware, and frame.
- Any exclusions linked to missed maintenance, blocked drainage slots or using the wrong cleaning products.
Ask the installer to set out in writing:
- Maintenance intervals (e.g. gasket inspection every 12 months, re-lubricating multi-point locking gear annually), and who is responsible.
- What counts as acceptable cleaning (non-abrasive products, no solvent on PVCu) so you don’t void the guarantee.
For materials, don’t just take a verbal promise. Require:
- Proof of material compatibility for sealants and packers with PVCu/ aluminium / timber frames.
- Batch numbers for units and gaskets recorded on your paperwork, alongside the FENSA certificate number on completion.
Confirm the claim process before you sign:
- Exact contact details for warranty issues (phone and email).
- What evidence they need: photos of leaks, fogging between panes, draught testing, date of installation.
- Expected response times for an inspection and for putting the fault right.
- Whether the product warranty (glass and hardware) is separate from workmanship, and who handles each.
Keep copies of the contract, guarantee, FENSA certificate, unit stickers, and any service notes. If a unit starts misting or a seal fails after a storm in Manchester, those records are what let you enforce the guarantee without arguments.
Red Flags in Quotes and Contracts : When to Walk Away
If a quote or contract doesn’t feel right, walk away. Don’t assume you can “sort it later” once the frames are in and the glass is sealed.
Watch for vague scope, like “full window replacement” with no mention of A-rated glass, 28mm argon-filled units, or multi-point locking. Check the paperwork clearly states made-to-measure frames, internally beaded sashes, and Q-LON gaskets, not just “uPVC windows”.
Avoid contracts that:
- Miss out fitting dates or leave timelines “to be agreed”
- Shift all risk to you for “site conditions” without a survey
- Allow the installer to swap materials “of similar quality” without your approval
- Auto-renew “maintenance plans” unless you cancel in writing
Warranty terms should spell out how long the frames, sealed units, and hardware are covered, and what voids the guarantee. Don’t accept “lifetime warranty” without details, or terms tied to “regular maintenance” that never say what that actually is.
Check payment clauses carefully. Be wary of price increases for “market fluctuations” or “additional works as required” with no written variation process. Insist on:
- A fixed price in £ for the agreed spec (e.g. A-rated, low-E, argon-filled units)
- Payments linked to clear stages, not just “on delivery”
- A sensible balance held back until final inspection and sign-off
If a glazier in, say, Manchester pushes you to sign on the spot, won’t amend unclear clauses, or refuses to confirm the FENSA certificate number will be issued on completion, step away. Get the contract checked or use another firm before anyone orders frames or drills into your brickwork.
Frequently Asked Questions
Can Skylights Be Installed on Historical or Listed Buildings?
Yes, you can often fit skylights on listed or historic buildings, but it has to be done very carefully. You’ll usually need planning consent and approval from the conservation officer, plus detailed drawings showing low‑profile conservation glazing and discreet fixings. We’d use sympathetic materials and an experienced heritage contractor so the historic fabric and any FENSA aspects are properly respected.
Do Skylights Affect Home Insurance Premiums or Claims?
Yes, skylights can affect your insurance, but done properly they’re usually fine. If you use a reputable, FENSA-registered installer with documented, weatherproof products, most insurers are happy, whereas DIY or poorly fitted units can lead to higher premiums or claims being queried. Always tell your insurer, keep all invoices, and get a written 10-year guarantee.
How Do Skylights Impact Indoor Acoustics and Noise Transmission?
They can make the room a bit livelier acoustically, but it depends how they’re built and fitted. Go for laminated or A-rated double glazing (28mm sealed unit with argon fill) and a well-insulated frame to cut rain and traffic noise, and make sure it’s properly sealed. If you’re very noise‑sensitive, an acoustician can measure it and advise extra treatments.
Are There Tax Credits or Rebates for Energy-Efficient Skylight Installations?
Yes, there are some tax breaks and local incentives, but they’re more limited here than in the US. You mainly need skylights that are high-efficiency – think A-rated glass, 28mm argon-filled units – and you’d check schemes via GOV.UK, your local council and energy supplier. Keep invoices and product details, and run it past your accountant to be sure.
Can Skylights Be Integrated With Solar Panels or Roof-Mounted Equipment?
Yes, you can have skylights along with solar panels and other kit on the roof, but it needs planning together. We’d liaise with your solar installer to set panel layouts so they don’t shade the rooflights, make sure the flashing is detailed correctly, and leave safe access for maintenance, while keeping everything watertight and within the roof’s load limits.