What warranties do you offer?

Our windows are coated with Teknos coatings and they provide us with an excellent guarantee.
With minimum maintenance they will give decades of service.

There is an 8 years warrantied lifespan on opaque coatings and a 6 year warranted lifespan on
translucent coatings providing our maintenance procedures are followed. Please see our guidelines here.

This period can be affected by exposure. See table below. No re-coating will be required during this period provided the coating is not damaged (details are given below).

The Warranty covers the coating against:

  • Peeling.
  • Cracking (over greater than 5% of the coated areas).
  • Damage resulting from fungal growth within the coating.
  • Significant yellowing of the coating.
  • Premature erosion of the film leading to areas of exposed timber.

It does not guarantee against:

  • The exudation of resin.
  • Extractive staining around knots.

Once the joinery is supplied, the warranty remains valid, provided that:

  • The windows are installed in accordance with our instructions. Please check that there is no damage to the coating, such as chipping, staining etc.
  • Should the coating become damaged when the windows are installed, the coating is promptly repaired in accordance with our remedial coating instructions, please contact us for details.
  • The coating is cared for in such a way that it is not damaged by abrasion, for example; window cleaners ladders.
  • The coating, and area surrounding the coating, is not cleaned with strong chemicals.
  • The coating is cleaned at specified intervals so that dirt retention does not lead to excessive mould growth. Such mould growth is more likely to occur on North facing elevations.
  • Only coatings recommended by us are applied to the joinery.
  • The correct coating maintenance schedule is followed.
  • The site is not exposed to excessive industrial pollution.


  Moderate: typically noncoastal areas at low altitude Harsh: this would include areas within 0.5 miles of the coast Extreme: areas of high altitude and expose
Sheltered e.g. beneath porch or large roof overhang 8 years for opaque coatings 8 years for opaque coatings 7 years for opaque coatings
6 years for translucent coatings 6 years for translucent coatings 5 years for translucent coatings
Partly sheltered, e.g. window built back in reveal. 8 years for opaque coatings 7 years for opaque coatings 5 years for opaque coatings
6 years for translucent coatings 5 years for translucent coatings 3-4* years for translucent coatings
Not Sheltered, e.g. face of building 7 years for opaque coatings 5 years for opaque coatings 5 years for opaque coatings
5 years for translucent coatings 3-4* years for translucent coatings 3-4* years for translucent coatings

We are registered with QANW and our warranties are protected by an insurance policy, underwritten by an onshore, UK-based, FSA registered insurer. In the event that Isis Joinery Ltd ceases to trade, and are unable to honour their warranties, QANW with the insurer and its agents take the place of Isis Joinery Ltd and the policy of insurance taking the place of their warranty. For more information click here. Please note, warranties offered by our partners George Barnsdale Ltd may vary and you will be advised accordingly at time of order.


Astragal Bars

An astragal bar is an industry term for a glazing bar that is applied to a piece of glass to give the impression of smaller pieces of glass. Astragal bars are aesthetic replications of the original narrow glazing bars, but give much better thermal performance.

Cill Extension

A cill extension extends the outside of the window to overhang the brickwork and provides a drip to stop water running down the wall. Windows are either fitted onto a separate stone cill or require a cill extension to provide this function.

Cill Side Extension

A cill side extension extends past the side of the frame. This is a common feature in many properties and allows original windows to be replaced without needing to make good any brickwork.

Fully Finished

Fully finished refers to each window being supplied, fully painted, glazed and ready for installation. Many carpenters and joiners just supply windows without glass or paint leaving it to the owner or builder to glaze an paint when the window has been fitted. This practice is troublesome as it is usually done with substandard materials in substandard conditions. All of our windows are supplied as fully finished

Case Studies

Click on images below

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Call-back Service

Have you a project that you would like to talk to us about? Let us call you back!




Contact Us
Email: info@isisjoinery.co.uk
Telephone: 01981 580237 or
0845 644 3785
Fax: 0844 376 9979
Isis Joinery Ltd, Ross on Wye, Herefordshire.
Company Reg Number: 5708071
VAT Registration Number 881 503524