Timber Lantern Guarantee and Maintenance Manual

Below are the main exerts from our Guarantee and Maintenance Manual.

To read / download a full PDF copy please click HERE

Materials and Structural Integrity

All materials used in the construction of our roof lanterns are guaranteed for a period of:

  • 10 years for structural timber / glazing capping.
  • 5 years manufacturers guarantee for standard double glazed units.
  • 2 years manufacturers guarantee for electric motors and controller units.

(please see appendix A for glazing guarantee period and below for Electric Motors and Control Units). The structural integrity of each roof lantern is also guaranteed against failure assuming that no other external influences cause an adverse effect.


If others install the lantern, our guarantee only covers the materials used, including the glass. Any leaks that may occur would be down to the installer.

Glass Units

As stated in appendix A, the double glazed units themselves are guaranteed for a period of 5 years. This does not automatically cover the labour cost for replacement although in practice we will sometimes accommodate this cost depending on the individual circumstances.


The lantern finish is factory sprayed, with industry standard micro porous paint designed for external joinery (Teknos AQUATOP 2600-24 a highly versatile, robust and easy to use topcoat, which typically is used for exterior windows, doors, shutters, conservatories or claddings).

We apply 2 coats of primer and 3 coats of topcoat, applied with an airless spraying system to guarantee a minimum of 200 microns of paint per wet pass.

The paintwork should stand up very well and give many years of service, but it would pay to inspect the exterior of the lantern at least once a year.

We recommend the following to maintain and extend the life of your exterior:

  • Once cleaned, scrape, lightly sand and touch up any necessary areas with a matching microporous paint or stain. Any bare wood should be primed first.
  • Weather seals to opening skylights / sashes should be checked and cleaned.
  • Any vents should be cleaned, and any blockages removed.
  • Timber is a natural product and therefore performs differently through the year.

Generally, the only likely maintenance aspect in this respect is that should a corner joint in the lantern cill open up slightly it would be advisable to fill the joint with ‘Painter’s mate’ or a similar proprietary flexible filler and touch up with white paint afterwards. A small amount of movement in the lantern structure is quite normal for any timber product and does not impair the structural integrity.
Always follow the instructions given by the paint manufacturer.


Hardwood in many cases is now ‘engineered’, which means that it comprises several layers of timber bonded together. This increases stability and strength but a by-product is that on rare occasions a small hairline crack may appear due to fractional movement. This is not structural and will not impair the integrity of the lantern. A small touch up with painters mate / paint will remedy the situation.

Lead Ridge Capping:

Lead ridge cappings work extremely well and will last for an exceptionally long time.

HOWEVER, although patinated on both sides before delivery to site they must be re-patinated externally once the lead capping has been finally dressed down by whoever is installing the lantern. This is to prevent oxidization of the lead which can look a bit unsightly and run down onto the glass units. Eventually the capping will simply weather down, but it is recommended that the lead ridge capping is re-patinated every year.

Lead cladding to rafters will also need re-patinating if it is used with self-cleaning glass and / or it is required that the lead stays its original colour.

Self Cleaning Glass (Bio-Clean):

Self-cleaning glass works well. However – 2 important points:

  • Self-cleaning glass is not ideal with a lead ridge capping. The integrity of the lantern is not impaired but, in some instances, lead oxide from the capping has been known to cause some streaks on the external glass units. To minimize the risk of this we recommend frequent patination of the lead. See appendix A under self clean glass.
  • There are specific cleaning agents that we recommend for self-cleaning glass which do not harm it. Please see Appendix B.

Electric motors and control units

These have a manufacturer’s guarantee of two years. If a replacement unit is needed, we will supply one under guarantee, but the electric installation work / interface is not our responsibility. If the unit fails, we purely supply a new unit by post. The faulty unit would need to be returned for inspection first.