A skylight is the most rewarding feature in many homes across Buckinghamshire, Hertfordshire and North London - and the most common point of entry for water. Cut into the roofline, sealed with flashings that flex with every temperature swing, and glazed with sealed units that have a finite service life, rooflights demand more maintenance than any other roof penetration. When they fail, they fail conspicuously: a drip onto the landing, a brown streak down the plaster, or condensation running down the glass so heavily it pools on the sill.
Kingsway Roofing repairs and replaces Velux, Fakro, RoofLITE and all major rooflight brands across Barnet, Finchley, Muswell Hill, St Albans, Harpenden and the wider region. We do not just turn up with a tube of silicone. We diagnose the actual failure - is it the flashing, the seal, the glazed unit, or the surrounding roof covering? - and we fix that, with the correct manufacturer parts and compatible materials, so the repair holds through the next decade of storms and sun.
The loft conversion boom across North London and the Hertfordshire commuter belt over the last twenty years means our area has an unusually high density of skylights, many of them now reaching the age where seals fail and flashings perish. If your Velux was fitted when the conversion was done and nobody has looked at it since, it is due for a proper inspection. The good news: most skylight problems are fixable without replacing the whole window, and we will always repair before we replace.
Why Choose Kingsway
What We Deliver
Velux, Fakro and all major rooflight brand repairs
Replacement of failed double-glazed units
Lead and flashband flashing replacement around skylights
Reseal and rebed leaking rooflight kerbs
New skylight installation into existing roof structures
Condensation and ventilation advice for every property
Is It Time?
Warning Signs You Should Not Ignore
As specialist roofing contractors covering Buckinghamshire, Hertfordshire and North London, these are the issues we see most often - and what they typically mean for your property.
Water staining around the skylight frame
Brown or yellow tide-marks on the plaster around the opening are the clearest sign that water is tracking in - usually at the head flashing where the skylight meets the roof above. This is rarely a glazing problem; it is almost always a flashing detail that has lifted, cracked, or been installed without enough upstand. The longer it runs, the more the timber frame and plaster suffer.
Condensation running down the glass
Some condensation in cold weather is normal, but persistent streaming that pools on the sill means the sealed unit may be failing or the room ventilation is inadequate. We assess whether the issue is the window or the humidity, and we advise on both. In many loft conversions across Barnet and Finchley, the fix is ventilation as much as it is the skylight itself.
Misted or fogged double-glazing
If there is moisture permanently trapped between the two panes of your skylight, the sealed unit has blown. The desiccant inside the spacer bar is saturated, the seal has failed, and the insulating gas has escaped. The unit will only get worse - and in freezing weather you may even see ice crystals inside. The glass needs replacing, which we do with manufacturer-compatible sealed units.
Cracked or chipped glazing
A crack in a skylight pane - whether from impact, thermal stress, or a falling branch - is a failure waiting to happen. Even a small chip weakens the toughened or laminated glass and will spread with temperature changes. We replace cracked panes with the correct specification glazing, matching the original unit's thickness, tint, and safety rating.
Draughts or cold spots below the skylight
If the area beneath your rooflight is noticeably colder than the rest of the room, the seals between the frame and the opening, or the sash and the frame, have degraded. Warm air is escaping and cold air is dropping in. On modern Velux windows this is often a perishable gasket; on older skylights it can be the whole frame. We identify the gap and seal it properly.
Visible gaps in the flashing around the frame
From the ground or through binoculars, if you can see daylight between the skylight frame and the roof tiles, or if the lead flashing has lifted away from the upstand, water is getting in. Lead flashings fail through thermal movement and fatigue; soaker aprons crack; and the felt underlayment around the opening perishes. We strip and re-detail the flashing using manufacturer kits for a weathertight junction.
Specification Matters
The Right Approach for Your Property
Flashing & Seal Repair
Most common skylight fixThe majority of leaking skylights across St Albans, Harpenden and North London do not need new glass - they need the flashing and seals doing properly. We strip the existing flashing, check the underlayment and soakers beneath, re-detail the upstand with manufacturer-compatible kits, and re-bed the frame. This is the fastest, most cost-effective fix when the glazing itself is sound.
- Manufacturer flashing kits - Velux, Fakro, RoofLITE and others
- Lead soaker and apron replacement where the original has failed
- Frame-to-structure seal renewal with compatible mastics
- Underlayment check and replacement around the opening
- Ideal when glazing is clear and the unit is not blown
Sealed Unit Replacement
For blown or cracked glassWhen the double-glazed unit has failed - misted between the panes, cracked, or losing its argon fill - the glass itself needs replacing. We measure the existing unit, source a manufacturer-compatible replacement with the correct U-value, safety rating, and tint, and fit it into the existing frame. You keep the window you have and regain the clarity and insulation you have lost.
- Exact-specification replacement sealed units
- Argon-filled, low-E double or triple glazing to match original
- Toughened or laminated safety glass as required by Building Regs
- Re-using the existing frame and sash - no structural work
- Restores insulation and eliminates condensation between panes
Full Skylight Replacement
When the frame has failedIf the skylight frame is rotten, the sash is warped, or the window is a discontinued model for which parts are no longer available, a full replacement is the right answer. We remove the old unit, check and repair the structural opening, and install a brand-new Velux or Fakro roof window with the correct flashing kit and underlayment. It is also the opportunity to upgrade to a higher-specification glazing or a centre-pivot vs top-hung configuration.
Why Kingsway
Why Homeowners Across Bucks, Herts & North London Choose Us
We know loft conversions across North London and Herts
The loft conversion wave that swept through Barnet, Finchley, Muswell Hill and the Hertfordshire commuter towns means our area has thousands of skylights installed over the last twenty years, many now reaching the age where flashings and seals fail. We have worked on the conversions themselves, so we understand how the skylights were detailed - and where they tend to leak.
We use manufacturer parts, not generic substitutes
Velux flashing kits, Fakro sash seals, RoofLITE glazing units - we fit the correct manufacturer components for the brand of window you have. Generic flashband and aftermarket seals might stop a leak temporarily, but they do not accommodate the thermal movement the window was designed for, and they fail again within a season or two. We do it the way the manufacturer intended.
Employed roofers, never subcontractors
The person who surveys your leaking skylight is the same person who fixes it, and the same company that guarantees the repair. We do not sub out skylight work to glaziers or general builders. Rooflight repair is a roofing discipline - it sits at the junction of glazing, flashing, and roof covering, and it needs a roofer who understands all three.
Emergency tarping for active skylight leaks
When a skylight is letting in water, we can usually get a temporary weatherproof cover in place within 24 hours across our coverage area while the permanent repair or replacement is arranged. We carry the materials on the van and we know the difference between a drip that can wait a week and a pour that needs covering today.
Checkatrade-vetted with unedited local reviews
Every skylight repair we complete is reviewed by the homeowner on Checkatrade, and we publish those reviews without editing. Our reputation across Buckinghamshire and Hertfordshire is built on the conversions and extensions we have worked on for years - and on the fact that when a repair does not hold, we come back and make it right.
Ventilation advice, not just glass replacement
Skylight condensation is often a ventilation problem dressed up as a glazing problem. Before we sell you a new sealed unit, we assess the humidity and airflow in the room below - particularly in loft conversions where moisture has nowhere to go. The right fix might be a trickle vent, an extract fan, or a change to how the space is used. We tell you what will actually work.
Coverage
Covering Buckinghamshire, Hertfordshire & North London
We cover the full spread of our region - from the Chilterns in Bucks through the Herts commuter belt and into the northern London Boroughs. If you are in any of the areas below, we can be with you for a free survey within the week.
Not on this list? Contact us - we cover the full surrounding area and will confirm coverage when you get in touch.
Related Services
Other Services You May Need
Pitched roof tile, slate and general leak repairs - often the source of water tracking toward skylights.
EPDM and GRP flat roof repairs for rooflights and glazing set into flat roof structures.
Chimney stack and flashing repairs - another common leak source near roof windows.
New roof construction incorporating skylights and rooflights from the outset.
Common Questions
Frequently Asked Questions
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