Black Pig have been members of the Glass & Glazing Federation since 2014.

The Glass and Glazing Federation (GGF) is the industry’s main trade federation. Being the industry authority, the GGF promotes best practice and sets the highest technical and health & safety standards.

By using a GGF member our clients benefit from using a company that:

  • Has financial stability and has been trading for a minimum of 3 years – there are no phoenix companies in the GGF.
  • Has been vetted and has premises, products and employees fit for purpose.
  • Employs trained professionals to ensure your installation is to the highest technical standards as outlined by the GGF Glazing Manual written by the industry’s leading experts.
  • Complies with the GGF Consumer Code of Good Practice which has strict requirements regarding the conduct of Member companies and ensures they comply with all relevant consumer legislation. All GGF Member companies are audited on a regular basis to ensure their compliance.
  • Offers you free automatic deposit protection using the GGF Deposit Indemnity Fund set up in 1981 – now the industry’s best deposit protection that safeguards your deposit and instalments of up to 50% of the contract value or £12,500 (whichever is lesser).
  • Offers you free access to our Conciliation Scheme in the unlikely event of a dispute with a GGF Member company. Rest assured you will not be left alone – the GGF will help resolve the dispute and if it cannot be resolved (very rare), the Glazing Arbitration Scheme is there to help you reach resolution.
  • Offers you transferrable warranties – should you sell your property, you can advise the buyer that the guarantee can be transferred over to them by the Member Company who fitted your windows for a reasonable fee.

Black Pig Guarantee (short form)

We give a 25 year guarantee for our labour and materials and the the same for all IGU’s supplied by us (this excludes joinery units which have different conditions). If for some reason you are not satisfied with our work, you must contact us in writing, preferably including photographs, let us inspect the installation and carry out any remedial work we deem necessary, at our expense. You agree to allow us or our representatives full access to the site and the areas of work disputed. This guarantee assumes that the green oak frame has been allowed to acclimatise in accordance with our recommendations and that the green oak framing was adequate. This guarantee is limited to our work only, covered by a contract signed by the client. No consequential losses will be covered.

What does this mean ?

25 Year guarantee:

This is the effective life of the IGU (Insulating Glass Units – double glazed or triple glazed units) which is understood to be 25 years (based upon research by the Building Research Establishment back in the 70‘s) however technology has moved on since then and we expect our well made and properly installed modern units to far exceed this.

Client responsibility:

One of the principles behind our work is that the client should be fully aware of the risks involved in building in green oak (or other green timber) and be aware of their responsibilities in helping to control the drying process. In signing our contract the client or their agent acknowledge that the client will have, as an absolute minimum, fully read our website and understood it. We are only a phone call away if anyone should have any questions. In addition we try to verbally brief all clients at the time of site survey or if required during our time working on site.


This guarantee is fully transferable as long as the new client is also fully briefed as to the vagaries of green oak. In order to transfer the guarantee the new client will need to contact us and in writing confirm that they have read our website and acknowledge their responsibilities to their frame. Again we are always available to answer questions.

Glass Units:

The IGU’s carry a 5 year manufacturer’s guarantee against seal failure (misting up).  This manufacturer’s guarantee only covers against manufacturing fault leading to unit failure. We believe that the IGU’s that we supply are unlikely to fail because we only source them from well established unit manufacturers that we have inspected and with whom we have established a good working relationship. IGU’s are all manufactured to the same BS standards but are not necessarily all the same; there are a number of subtle differences that are only apparent if you know the factory that they come from and the processes involved. These differences can affect both the longevity of a unit and its structural safety. Black Pig has been trading since 2005 and Simon installed his first units in 2002. In all that time we have only seen a handful of units that have failed after installation. We do replace a couple of units a year that are broken by golf balls or strimmers, this work however is chargeable! As a consequence and having designed our system accordingly, we are happy to extend this 5 year period to match the 25 year guarantee that covers our labour and materials.

The Green Oak Frame:

Whilst we do everything reasonably possible to reduce the risk of water leakage (which is very rare) we cannot give a 100% guarantee against leakage.  Any leakage would be primarily caused by excessive movement of the green oak frame and is dependent on the quality of the green oak used and the speed that the frame dries out. Both these factors are outside our control.  We therefore strongly recommend that any part of a green oak frame that is to receive glazing or joinery is made from glazing quality oak, i.e. straight grained and free from knots with clean crisp arrises and no sap wood. Very importantly we would further advise that any heating in the building is kept to a minimum for as long as possible (ideally 3 winters, longer if possible) so that the green oak dries out as slowly as possible.


By leakage we are referring to water leakage, not air leakage or drafts. We believe that our installations are airtight, as shown by our work never having failed an airtightness test. However, if we open up liability to air leakage then we will get the blame for every draft that happens to be near our installations. This is just not practical – sorry!


One of the very few disadvantages of using oak as a building material is that water staining is very visible. Large expanses of glass can attract condensation, depending upon the atmospheric conditions and other factors; whilst this can be very apparent, it is not a leak. It is relatively straight forward to clean off by scrubbing with a steam cleaner. The risk of condensation can be dramatically reduced by specifying the most appropriate unit specification, something that we do as standard for every project we work on.

Our approach:

If a job should appear to leak then we will initially request photos and then return to site to assess the problem at no charge (assuming that the job is within mainland England and Wales; any job outside mainland England and Wales will be subject to discussion). We will diagnose the cause of the problem and recommend a course of action.

Joinery (opening windows & doors):

If we buy in joinery units, we always purchase from a recognised joinery manufacturer and these units are covered by the manufacturers own guarantee. If we subsequently install these bought in joinery units, then we guarantee our installation but not the actual unit. Black Pig joinery that is made to our specification and supplied by us is subject to a 10 year workmanship and materials warranty. This warranty excludes abuse and general wear and tear.

Black Pig joinery is usually supplied with an oiled finish and will therefore require a small amount of maintenance. We recommend that once a year for the first 2-3 years, during a dry spell, that the units are washed down with a mild detergent and if deemed necessary a light sanding and then re oiled.

Oak doors, windows, associated joinery and ironmongery are manufactured and installed to tight tolerances. Whilst oak is a beautiful and long lasting natural material, its use in joinery units will mean these units will require a period of time to settle in after installation. Depending upon exposure and other local environmental factors they sometimes need some adjustment. This is well within the ability of a local qualified carpenter and as such we specifically exclude any revisits (to site) to adjust doors, windows or ironmongery as the cost is unfortunately prohibitive.

In conclusion:

  1. Should one of our glass units should fail (mist up) within 25 years we will replace it free of charge, including all parts and labour.
  2. Should there be a water leak that can be traced back to our work within 25 years, then we will fix it free of charge, including all parts and labour.
  3. Joinery is covered under its own terms.
  4. No consequential losses will be covered.

We take a great pride in our work and are constantly improving and upgrading our system. We welcome any feed back, good or bad as this will help in any future improvements that we can make.

Company Information

Black Pig Frame Finishing Ltd is registered at Companies House as a private limited company, so if you are so inclined you can look up our accounts or other exciting information at

Company registration no. 5578405

VAT registration no. 801 0401 09