The short answer
Possibly. A sealed glass unit that has misted inside the panes is the kind of failure a maker's guarantee is written for, so check whether yours is still in cover before you order anything. Find the paperwork, read the date on the spacer bar, and ask the maker to confirm their terms. If the unit is out of cover, a new sealed unit is the straightforward route.
Start with the paperwork, then the glass itself
Two things decide whether a claim is worth making: who made the unit, and when. Both can usually be found without taking anything apart.
Begin with whatever came with the house or the job. The original invoice, the installer's certificate of completion, a product brochure or an emailed order confirmation will usually name the maker and the date. A guarantee card or a warranty registration is better still. If you bought the property, the seller's pack or the solicitor's enquiries may hold the same papers.
If there is nothing on paper, the glass can tell you. Sealed units carry a small mark stamped or printed on the spacer bar, the metal or plastic strip running round the edge between the panes. Look at the edge of the glass where the frame meets it. The mark can include the manufacturer's name or code and a date, typically a month and year. A torch held at an angle against the glass helps to read it. Take a photograph of it, with a coin or a ruler beside it for scale.
Sometimes the frame helps too. Some makers place a label on the frame, the head of a roof window or the inside of a lantern curb. Write down what you find, along with the size of the unit and the make and model of the rooflight. The measurements are the same ones we would need, as set out in how a failed rooflight is measured for its replacement.
What you are looking for in the terms
Guarantee wording differs from one maker to the next, so read yours rather than assuming. These are the points that usually decide a claim.
| Point to check | Why it matters |
|---|---|
| Start date | Cover runs from the purchase or installation date, which may differ from the stamp on the glass |
| What counts as failure | Some terms name moisture between the panes; others name only a loss of seal |
| What is supplied | A new unit only, or also access and fitting |
| Who can claim | The first owner only, or later owners of the house |
| Conditions | Proof of purchase, correct installation, no alteration of the glass |
The period of cover is on the certificate or in the maker's published terms. It varies by product and by date of sale, so the maker's own terms are the source. Ask the maker for the wording that applied when yours was bought.
The glass-only point is the one that catches people out. A guarantee may produce a replacement unit at no charge and still leave you to arrange and pay for the fitting, or for access at height. Read that line before you assume the whole job is covered.
Claiming, and what to expect from the maker
A claim is a short exercise in evidence. The more of it you hand over at the start, the quicker the answer comes back.
- Photograph the misting in the morning, when it is at its clearest, and again from close to the edge of the glass.
- Photograph the date mark on the spacer bar and any label on the frame.
- Send the invoice or order number, the address and the unit size to the maker's customer team.
- Ask in writing whether the unit is in cover and what exactly they would supply.
Do not let anyone drill, vent or treat the unit before the maker has replied. Altering a sealed unit can change how its cover is treated, which is one more reason to think twice about a demisting service. Our page on demisting misted skylight glass explains why we recommend a new unit instead.
If the maker agrees to a replacement, they will supply the unit on their terms, and you choose who fits it. Lead times depend on the size and build, and our answer on how long a replacement glass unit takes to arrive gives a general picture. Where the maker has stopped making the product, see replacement units for a skylight that is no longer made.
When the cover has run out
A unit outside its cover is a normal situation for a rooflight that has had years of sun, frost and damp. It is not a dead end.
The glass is replaced with a new factory-sealed unit, made to the size measured on site, and the surrounding seals and trims are renewed where needed. The job is an installation like any other, and it comes with a written quote. Where the whole frame has aged, renewing the rooflight may be the sounder choice, and we say so at the survey.
A replacement is also an opportunity. If the old unit was an ordinary double glazed pane, the new one can have a laminated inner pane, warm edge spacers and better coatings, and the glazing build is written into the quiet spec that comes with the quote. The new glazing carries its own paperwork from its maker, and our work on it is covered by our 10-year workmanship guarantee. Keep both papers with the house documents, since a future buyer's solicitor may ask for them.
Questions about cover on a misted unit
Does the guarantee pass to me if I bought the house?
That depends on the wording. Some terms follow the property and others stay with the first purchaser. Check the clause on transfer, and send the maker your proof of ownership with the claim.
What if the spacer bar has no date on it?
Then the invoice or the installer's records are your evidence. If neither exists, describe the rooflight, send photographs to the maker and ask them to identify it from the profile and the glass build.
Is a blown unit the same as a misted one?
In everyday use, yes. Both mean the seal has failed and moisture has entered the cavity. The wording a maker uses may differ, so see what a blown double glazed unit in a skylight means before you write your claim.
Can you replace a VELUX pane that is still in cover?
Whether we fit it or you use the maker's own route is your decision, and the maker's terms usually apply to the product either way. For the options, see misted VELUX windows: new pane or new window. If you would like a written quote to set against the maker's offer, get a quote, and read more on the misted and failed rooflight replacement page.