Conservation Rooflight Maintenance: A Practical Care Guide for Steel Rooflights

A conservation rooflight is a small steel window set into one of the most exposed parts of the building. Conservation rooflight maintenance comes down to three things: keep the coating intact, keep water moving off and around the frame, and write down what you did. Done twice a year, it takes less than an hour per unit and protects both the building and the guarantee.

Why does maintenance matter on a conservation rooflight?

Maintenance matters because a steel rooflight lasts as long as its coating does, and because the longer guarantees are conditional on proof that the unit has been looked after. Neglect shortens both the life of the frame and the value of the paperwork.

Steel gives conservation rooflights their slim, flush profile, but it rusts once water reaches bare metal. The factory coatings, a polyester powder coat classified for highly corrosive environments in one case and a deep black matt paint finish in another, are robust but not self-healing. A chip left open for a few winters becomes a rust blister, and the damage spreads beneath the surrounding finish.

Guarantees are the second reason. Frame finishes carry longer cover than moving parts, and at least one manufacturer ties its extended guarantee to registration and a maintenance record.

The third is the building. A blocked head gutter or lifted soaker lets water into rafters and plaster that are often historic and costly to repair. For the detailing that should be in place from day one, see our installation and flashings chapter.

A maintenance schedule for conservation rooflights

A sensible routine is a light monthly check on anything that moves, a proper clean and inspection every six months, a closer annual review, and a quick look after any major storm. The table below combines the published guidance of both manufacturers into one working schedule.

When	Task	Notes
Fortnightly	Open and close motorised units	Keeps motors and chains working; a unit left shut for months can stick
Monthly	Light oil on the manual winder spindle	A drop or two only; wipe away excess
Monthly	Open and close manual units fully	Regular use keeps seals from bonding to the frame
Every six months	Clean frame, glass and seals	Warm water, a little washing-up liquid, soft cloth, rinse clean
Every six months	Clear the top gutter of the rooflight	Leaves, moss, twigs and tile chips are the usual culprits
Every six months	Inspect the coating	Look for chips, cracks, blistering or rust spotting
Annually	Oil hinges sparingly	Light machine oil; avoid getting oil on seals or glass
Annually	Check flashings, soakers and roof covering	Look for lifted lead, slipped slates or tiles, open joints
Annually	Check internal lining and reveal	Staining, flaking paint or damp are early warnings
After storms	Visual check from inside and, if safe, outside	Debris in the head gutter, displaced slates, wind damage to open units

Near main roads or dusty farm activity, clean more often: grime holds moisture against the coating.

How to clean a conservation rooflight

Clean with warm water, a small amount of mild detergent and a soft cloth or sponge, then rinse with clean water. Never use abrasives, solvents or scouring pads, because they wear the coating you are trying to protect.

Frame. Work from the top down, paying attention to the head and upper corners. Rinse thoroughly, as detergent residue attracts dirt.

Glass. Clean with the same solution and rinse. De-ionised water reduces streaking. If the outer pane has a self-cleaning coating, check the manufacturer’s guidance first, and never use a blade. Our glazing and security chapter covers glass specifications.

Weather seals. Wipe with a damp cloth. Grit on a seal abrades it each time the casement closes and stops it seating properly. Do not grease seals unless the manufacturer says so.

The rooflight’s top gutter. Most conservation rooflights have a small channel across the head that diverts water running down the roof around the sides. It cannot be seen from inside, so it is easily forgotten. Filled with leaves or tile fragments, it backs water up under the frame and holds moisture against the coating. Clear it with a soft brush and rinse it through.

Access. Clean from inside with the casement fully open only where that is safe. On high or steep roofs use a roof ladder, tower or existing scaffold. Never lean out of an open rooflight to reach the head.

Ironmongery, hinges, motors and gas struts

Moving parts need a small amount of lubrication and regular use. The winder spindle wants a drop of light oil monthly, hinges want oiling sparingly once a year, and motorised units should be run at least every couple of weeks.

Manual winders. Hand and pole winders work through a threaded spindle; a little light oil keeps them smooth. If one becomes stiff, do not force it. Check the casement is not binding on its seal first.

Hinges. Oil sparingly once a year and wipe off any excess before it reaches the coating or glass.

Motors. Run motorised units regularly. An open motorised rooflight is not locked in position: strong wind can drive it closed. Keep hands and objects clear of the frame.

Gas struts. Escape units and some larger rooflights use gas struts, which weaken with age. If a casement no longer stays open unaided, have the strut replaced through the manufacturer. On an escape rooflight this is a safety matter, as the Building Regulations expect an escape window to stay open without being held.

Motors, struts, blinds and controls usually carry around 12 months’ cover, so report early faults promptly.

Inspecting the coating and dealing with chips

Look over the whole frame every six months for chips, scratches through to bare metal, cracking, blistering or orange rust spotting. If you find damage, photograph it, note the date in the building log and contact the manufacturer for advice on repair.

The usual causes are scaffolding, dropped tools, slipped slates and abrasive cleaning. We do not recommend improvising with a general-purpose paint: an incompatible product can trap moisture or fail to bond, and may affect the guarantee. The manufacturers will advise on the correct method and material for their finish. Clement asks for problems to be reported within 48 hours of discovery; The Rooflight Co. asks owners to report coating damage for assessment.

When other trades work nearby, ask them to board over the frame first. It costs very little compared with a damaged finish.

Flashings, soakers and the roof around the rooflight

Check the flashings, side soakers and surrounding slates or tiles at least once a year. Most leaks blamed on rooflights start in the roof around them.

• Head flashing. Tight to the frame and dressed under the course above.
• Side soakers. Lead soakers at each course are the traditional detail on sensitive buildings. Check none have slipped.
• Cill or apron flashing. Flat, unsplit, and discharging cleanly onto the course below.
• Slates and tiles. Slipped or cracked units above the frame can block the head gutter.
• Lead condition. Splits, fatigue cracking, or white carbonate staining washing onto the glass.

Lead repairs are specialist work; our Index lists leadwork specialists experienced on traditional roofs.

Condensation or a leak? Diagnosing damp around a rooflight

Water inside around a rooflight is either condensation forming on cold surfaces or rain getting in from outside. The pattern tells you which: condensation appears on cold mornings regardless of rain, while leaks follow rainfall and wind direction.

Sign	More likely condensation	More likely a leak
Timing	Cold, still mornings; after cooking, bathing or drying clothes	During or after rain, especially wind-driven rain
Location	Evenly across the inner glass and frame; runs to the cill	Concentrated at a corner, the head or one side
Staining	Mould spotting on reveals and lining	Tide marks on plaster, often spreading below the rooflight
Room	Bathrooms, kitchens, bedrooms with doors shut	Any room; not linked to activity
Dry weather	Still appears	Stops

Some rooflights have a condensation channel at the base of the frame that drains outwards through small holes in the cill. If those holes block, the channel overflows and looks like a leak.

Condensation is solved in the room: working extract fans, trickle ventilation, regular opening, and no indoor laundry drying. Our article on the problem with condensation explains the mechanism in older buildings.

For a leak, work outwards: head gutter, head flashing, soakers, roof covering above, then the glazing seal. A hose test run section by section from the bottom up, with someone watching inside, usually isolates the source. The correct detailing is in our installation chapter.

Exposure and coastal sites

Salt-laden air attacks steel coatings far faster than inland air, so coastal and exposed sites need extra care and a conversation with the manufacturer before ordering.

The coating system and its pre-treatment do most of the work. The Rooflight Co. offers a hot zinc spray pre-treatment beneath its powder coat, but its frame guarantee still reduces nearer the sea: ten years beyond 5 km, five years between 500 m and 5 km, and twelve months within 500 m. Clement does not recommend its rooflights for marine environments within five miles of the coast and asks to discuss such sites directly.

On exposed sites:

• Give the manufacturer the distance to the coast and the slope’s orientation at quotation stage.
• Ask what pre-treatment and coating are proposed, and what guarantee applies.
• Clean at least quarterly; salt holds moisture on the finish.
• Inspect more often and report damage immediately.

Rooflight warranty registration and guarantees compared

Guarantees on conservation rooflights vary by component, and the frame finish carries the longest cover. Registering the unit and keeping a maintenance record are what secure the longer terms.

Component	The Rooflight Co.	Clement Windows Group
Standard cover	12 months, extendable on registration	Component-based, see below
Frame / finish	Mild steel frame: 10 years (over 5 km from sea). Zinc pre-treated frame: 10 years (over 5 km), 5 years (500 m–5 km), 12 months (within 500 m)	10 years on the paint surface
Sealed glazing unit	5 years (with silicone)	5 years on glass unit failure
Fittings and ancillaries	12 months (gas struts, motors, blinds, controls)	1 year on fittings
Internal timber lining	12 months	Not stated separately
Conditions	Register each unit by serial number; correct installation for the location; recorded maintenance	Report problems within 48 hours
Coastal note	Cover reduces nearer the sea	Not recommended within five miles of the coast

Terms change, so confirm them at order stage. Make registration a contractor handover item, with serial numbers noted against each rooflight location.

Keeping a building log

A simple building log, paper or digital, is the best maintenance tool you can have. It records what was installed, what was done and when, and it is the evidence a manufacturer will ask for if something goes wrong.

For each rooflight, record:

• Location, manufacturer, product, size, serial number and installation date
• Glazing specification and options (motor, blind, escape hinge)
• Registration date and guarantee reference
• Installer and leadworker
• Each inspection: date, who, what was done and found, with photographs
• Damage reported, to whom, and the outcome

Log the rainwater goods alongside: profile, when last painted and when last cleared. The record helps with later consent applications and future owners will value it.

Repairing surviving historic cast iron rooflights

Where an original cast iron rooflight survives, repair it before considering replacement. Historic cast iron rooflights are part of the building’s significance, and most defects can be repaired by a competent metalworker.

Victorian and Edwardian cast iron skylights survive on barns, stables, terraces and industrial buildings. Typical faults are corrosion, broken glazing, failed putty, seized stays and decayed upstands. Cast iron corrodes slowly compared with thin steel, so a poor-looking frame often has plenty of sound metal.

A typical repair sequence:

1. Record with photographs and measurements before removal.
2. Remove loose paint and corrosion, testing old paint for lead first.
3. Repair cracks, casting replacement parts from a pattern taken from surviving pieces.
4. Prime and repaint. Linseed oil paint suits cast iron frames: it stays flexible and can be maintained by rubbing down and recoating without stripping. See our page on linseed oil paint for cast iron.
5. Reglaze with appropriate glass and putty; overhaul the stay.
6. Renew flashings and upstand.

On a listed building, repairs that change glass or profile may need consent; our consent and permissions chapter explains when.

Inspect gutters, hopper heads and rooflight flashings on the same visit

The best time to check rooflights is on the same visit as the gutters and downpipes. The access is the same, the weather conditions are the same, and many rooflight leaks start with rainwater goods that are not coping.

Rooflights concentrate water: each head gutter throws it sideways onto the courses below, and the slope discharges into the eaves gutter. A blocked or undersized gutter overflows onto walls and back under the eaves; a blocked hopper head or cracked downpipe does the same lower down. One inspection shows the whole path of the water from ridge to ground.

Cast iron gutters, hoppers and pipes also need a repainting cycle with linseed oil paint every few years, alongside clearing and checking joints. If the rooflight work needs scaffolding, that is the cheapest moment to overhaul them. Our chapter on roof works and rainwater goods covers this in more detail, and our cast iron guttering and rainwater heads pages show the profiles available.

Common mistakes

• Using abrasive cleaners or scourers. They wear through the coating and create the damage you are trying to prevent.
• Forgetting the head gutter. It cannot be seen from inside, and it is where most debris-related leaks start.
• Improvising paint repairs. An incompatible product can trap moisture and affect the guarantee. Ask the manufacturer.
• Not registering, or keeping no log. Extended cover may depend on both.
• Leaving the frame unprotected during roof works. Dropped slates and tools chip coatings.
• Confusing condensation with a leak. Check timing and pattern first.
• Leaving motorised units unused. Faults surface after the guarantee has expired.
• Ordering a standard specification for a coastal site. Discuss exposure first.
• Replacing a repairable historic cast iron rooflight. Repair first.

Illustrative scenarios

The scenarios below are illustrative composites drawn from typical projects. They are not specific buildings or Tuscan Foundry commissions.

Where to go next

For existing installations, The Rooflight Co. handles maintenance and guarantee questions at customerservices@therooflightco.com. Other chapters of the Conservation Rooflight Guide cover specification, consent, glazing and installation.

Tuscan Foundry supplies cast iron gutters, downpipes and hopper heads to BS 460 for listed and traditional buildings, with an in-house linseed oil paint finish. A failing gutter below a rooflight undoes good flashing work above it, and a scaffolded roof is the cheapest moment to repair or replace one. Stock items dispatch promptly; bespoke and copy-cast items take around 12–14 weeks from pattern approval, so book our site survey service early in the programme.

Frequently asked questions

How often should I clean a conservation rooflight?

Clean a conservation rooflight at least every six months, using warm water with a little mild detergent and a soft cloth, then rinse with clean water. In polluted areas, beneath trees or near the coast, clean more often, as dirt and salt sit on the coating and hold moisture against the steel.

What should I use to clean a steel rooflight?

Use warm water, a small amount of washing-up liquid and a soft cloth or sponge, then rinse. Avoid abrasive cleaners, scouring pads, solvents and blades. De-ionised water reduces streaking on the glass. If the glass has a self-cleaning coating, check the manufacturer’s guidance before using any cleaning product.

Why is my rooflight leaking?

Most rooflight leaks start at the head, where a blocked top gutter lets water back up under the frame, or in the flashings and soakers around it. Slipped slates or tiles above the rooflight are another common cause. Check whether the water appears only during rain; if it appears on cold dry mornings, it is more likely to be condensation.

How do I tell condensation from a leak around a rooflight?

Condensation appears on cold mornings whether or not it has rained, spreads evenly over the inner glass and frame, and is worse in bathrooms and bedrooms. A leak follows rainfall, often wind-driven rain, and shows up at one corner, the head or one side, with tide marks on the plaster below.

How do I lubricate rooflight hinges and winders?

Put a drop of light oil on the manual winder spindle monthly and oil the hinges sparingly once a year. Wipe away any excess so it does not run onto the coating or glass. Do not oil the weather seals. If a winder becomes stiff, check that the casement is not binding before applying force.

What should I do if the coating on my rooflight is chipped?

Photograph the damage, note the date in your building log and contact the manufacturer for advice on the correct repair method and material. Do not use a general-purpose paint, which may not bond to the factory finish and could affect the guarantee. Report damage promptly; Clement asks for problems to be reported within 48 hours.

Why is my steel rooflight rusting?

Steel rooflights rust when water reaches bare metal through a break in the coating, usually from a chip caused during roof works, abrasive cleaning or debris sliding onto the frame. Salt air on coastal sites accelerates the process. Report rust spotting to the manufacturer early, before it spreads beneath the surrounding finish.

Do I need to register my rooflight for the warranty?

For The Rooflight Co., yes: the standard cover is 12 months, and the longer guarantees apply when each unit is registered by serial number, correctly installed for its location and maintained with a record kept. Check the current terms with whichever manufacturer supplied your rooflight and keep the paperwork with the building records.

How long is the guarantee on a conservation rooflight?

It depends on the component. Frame finishes typically carry up to ten years, sealed glazing units five years, and motors, gas struts, blinds and fittings around one year. The Rooflight Co.’s frame cover reduces closer to the sea. Confirm the current terms with the manufacturer at order stage.

Can I fit a conservation rooflight near the coast?

Possibly, but discuss the site with the manufacturer first. Clement does not recommend its rooflights for marine environments within five miles of the coast. The Rooflight Co. offers a zinc pre-treated frame, with guarantee periods that shorten closer to the sea. Expect to clean and inspect more often on exposed sites.

How often should motorised rooflights be operated?

Run a motorised rooflight at least every couple of weeks to keep the motor, chain and controls working. Remember that an open motorised unit is not locked in position: strong wind can close it. Faults on motors are usually covered for 12 months, so report them early.

Can an old cast iron rooflight be repaired?

Usually, yes. Cast iron corrodes slowly, and a frame that looks poor often has sound metal beneath. A metalworker can clean it, repair or recast broken parts, and repaint it; linseed oil paint suits cast iron well. On a listed building, check whether listed building consent is needed before starting.

Should I check the gutters when I inspect my rooflights?

Yes. Rooflights concentrate water onto the slope below, and a blocked eaves gutter or hopper head causes overflows that can look like rooflight leaks. Inspecting gutters, hopper heads, downpipes and rooflight flashings on the same visit shows the whole path of the water and saves on access costs.