What guarantees and warranties do composite doors come with?

A composite door's guarantee is not one single thing; the slab, parts and fitting are usually covered separately, so it pays to check each.

What the guarantees cover

A composite door comes with more than one guarantee, and understanding the split helps you know what is protected and for how long. The manufacturer guarantees the door itself against defects, while the installer guarantees the fitting. Within the door, the slab, the hardware and the glazing may each have their own terms. The table summarises the common elements and what they typically cover.

Durations vary by brand and installer, so the figures below are indicative rather than fixed. Always ask for the specific guarantee documents and read them, as headline claims can hide different terms for different parts of the door.

Indicative cover; durations and terms vary, so check the written guarantee.

Slab, hardware and glazing

The door slab guarantee is the headline figure many buyers focus on, often in the region of 10 years, covering manufacturing defects such as delamination of the skin, warping or significant colour fading. This is the part that reflects the durability composite doors are known for.

Hardware and glazing usually carry separate, sometimes shorter, warranties. Handles, hinges and the multipoint locking mechanism are moving parts subject to wear, so their cover may differ from the slab. Glazed units are typically guaranteed against sealed-unit failure, such as misting between the panes. Because these periods can differ, a door advertised with a long slab guarantee may have shorter cover on the parts you are most likely to need replaced, so check each.

Installation guarantee and insurance backing

Separate from the product guarantees is the installation guarantee, given by the company that fits the door. Correct fitting is essential, as a well-made door fitted poorly can leak draughts, sit unevenly or fail to seal, so this cover matters. The installer should guarantee their workmanship for a stated period.

An insurance-backed guarantee (IBG) is worth asking about. It protects the installation guarantee if the installer goes out of business during the cover period, so you are not left with worthless cover. Reputable installers, particularly those registered with a competent-person scheme such as FENSA or CERTASS, can often provide an IBG. Confirm whether one is included, what it covers and how to make a claim, and keep the paperwork safe.

Exclusions and protecting your guarantee

Guarantees come with conditions and exclusions, so read them. Common exclusions include accidental damage, misuse, lack of reasonable maintenance, alterations by others, and normal wear on items like seals. Some guarantees require periodic maintenance, such as cleaning and occasionally lubricating moving parts, to remain valid, and may need the door to have been fitted by an approved installer.

To protect your cover, keep all the documents together, including the order specification, manufacturer guarantees, installation guarantee and any insurance-backed certificate. Follow any maintenance the guarantee requires, and report problems promptly within the cover period. When buying, ask for all the guarantee terms in writing before you commit, compare them between quotes, and treat the durations and exclusions as part of the value, not an afterthought.

Frequently asked questions

Sources & further reading

• HomeOwners Alliance — front doors guide
• FENSA — installer registration and guarantees
• Which? — buying a new front door

Figures on this page are typical UK ranges drawn from published sources and depend on your specific door and opening. They are guidance, not a quotation.