Timber windows and doors made with traditional skills

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All joinery supplied by GBS is made with care & attention by our team of time served craftsmen and trainees all of whom are keen to produce a quality product to be proud of and one that will provide first class service.

The following information is offered to uphold and maintain the quality of products and service .

Timber source

All timber used by GBS in the manufacture of it’s products is sourced from importers and merchants that are FSC (Forest Stewardship Council) and PEFC (Programme for the Endorsement of Forest Certification) registered and as such operate a chain of custody from a sustainable source.

Commonly used Softwoods sourced from   uses
Redwood Sweden, Finland, Russia and Canada ll forms of joinery; some construction; panelling
Douglas Fir, Columbian Pine Canada & USA Panelling; heavy construction; joinery.


Commonly used Hardwoods sourced from   uses
Merranti. S.E. Asia Shop fitting, joinery, furniture, finishing’s, flooring.
Sapele, Iroko, Utile, Idigbo W Africa Shop fitting, joinery, furniture, finishing’s, flooring.
Oak Europe & USA Shop fitting, joinery, furniture, flooring, construction (Oak)


Timber Quality

Timber being a natural product is prone to defects and as such we endeavour to not only source the best possible quality of timber but to deal with as many of the defects as possible during the manufacturing process.

We do this by routing out large unsightly knots to a depth of approximately 5 mm and filling with a timber biscuit, removing dead knots and filling with two pack filler, we also cut out shakes and splits in the timber and laminate in new pieces.

GBS – Installation consumer

It is our utmost intention to arrive on time on pre arranged days, to be courteous and polite at all times and to go about our work in a professional manner with the least amount of disturbance to family life as possible. We understand that we are entering into your home and not a building site.

Our work will be carried out with both best practise and the health and safety of everyone concerned in mind.

The replacement of windows by GBS in the home will be carried out with the utmost care. However, the removal of old windows is a dirty job and whilst blankets and dust sheets will be laid to protect as best as possible and practical carpets and furniture. Carpets will be turned back if at all possible. We would ask that any light fittings ornaments pictures photographs and anything of particular value be removed from working areas also electrical equipment in particularly televisions and computers be adequately and satisfactorily protected or removed from working areas.

Where radiators are positioned beneath windows we will endeavour to work around them. However, if this is not possible they may have to be removed which may involve the assistance of a professional plumber to remove and to refit which would incur further charges.

Every care will be taken when erecting scaffolding and ladders, any disturbance to garden borders and plants will be repaired.

It is our intention to leave you pleased and completely satisfied with our service and your home enhanced by our products.

GBS – Installation trade

It is our utmost intention to arrive on time on arranged days, to be courteous and polite at all times to both customers and other trades and to go about our work in a professional manner with the least amount of disturbance as possible.

Our work will be carried out with best practise and the health and safety of everyone concerned in mind.

Fitting instructions – supply only

For the fitting of windows and door frames on a supply only basis to either the trade or diy consumer we offer the following advise and instructions which if not followed may affect warranty.

Once old frames have been removed the aperture must be cleaned and checked for mould growth and infestation and if necessary the area must be then sterilised.

This is also the opportunity to check the supporting brickwork and lintels and to carry out any remedial work that may be necessary.

Where frames are to be fitted into new build properties or extensions cavities must be closed in accordance with current building regulations.

Where ever practical windows and door frames should be fixed using galvanised metal straps or brackets fixed to the side of the frame and projecting inwards to be fixed to the brickwork .

Fixing points should be approximately 150 mm from top and bottom and at 450 mm thereafter, if this is not possible frames can be fixed using fox wedges at the head and cill points only, not within the length and breadth of the frame as this will result in pushing the frame out.

At no time should the main frame be drilled and screwed as this may result in moisture penetration. Frames can then be further fixed and sealed by using expanding foam around the perimeter tolerance before being finally sealed with either troweling mastic or gun sealant , under no circumstances must any form of silicone sealant be used.

Glass & Glazing instruction

Handling glass and glazing is dangerous and should only be carried out by competent persons wearing the correct PPE (gloves and goggles).

Where panes are too large for one person to manage safely assistance must be sought.

Single glazing must be set in a bed of linseed oil putty or similar bedding compound and pinned in place, pointed to the outside with putty or a timber bead.

Double glazing  units must be set on plastic packers in the bottom of the rebates to form a minimum of 3 mm void all around. Packers must be set into opposite corners on the horizontal and vertical, approximately 75mm in to “heel and toe” units when fitted in side hung casements to prevent sagging of the frame.

Units must be set against either a dry glazing tape, a butyle tape or a security tape then mass filled around the perimeter void running a bead of sealant on to the face of the glass before fitting external beads.

Under no circumstances must silicone sealant be used. External beads must be pinned 75 mm in from each corner and subsequently every 150 mm thereafter.

Where a drained system is used the void between the unit and the bottom rail of the frame must be kept clear.

Ironmongery – locks & furniture

Mortise locks and latches, multipoint espagnolettes and hinges must be checked and cleaned annually. Lock faces and latches, friction hinges and hinge knuckles should be smeared with a light oil applied with a rag. Do not use excessive oil or allow oil to penetrate timber.

Furniture should be wiped clean with a soft cloth and mild detergent before being polished.

Draught seals must be checked and cleaned annually with a mild soap solution.

Do not over paint seals.


Factory painting of windows and doors by GBS uses a specialised industry developed and recognised microporous paint system designed specifically for timber windows and doors to provide long lasting protection against weathering and to resist cracking and flaking.

Maintenance and redecoration will be required throughout the life of the product at intervals of between 8 – 10 years for light colours, reduced to 5 – 8 years for dark colours depending on exposure and orientation.

It is advisable to wash down paintwork annually with a mild detergent and soft cloth to prevent the build up of dirt . Do not use any abrasive products.

When re coating use only microporous paints, do not use traditional oil based paints or paints that will seal the surface.

This information is advisory based upon technical information from Teknos UK Ltd.

Please see warranties, terms & conditions.

Building regulations

All windows and doors manufactured and installed by GBS conform to current building regulations, in particular documents L – N – B – F.

Installations require inspection and certification, GBS employs the services of an independent RICS (Royal Institute of Chartered Surveyors) approved building inspector. Windows supplied for new build or extensions to property where the project is already covered by building regulation approval and inspection, require no further inspection or certification .

Building regulations do not state how requirements are to be met. The following is our understand of the requirements in discussions with our RICS approved buildinginspectors.

On a supply only basis customers must satisfy themselves that the windows and glazing that is provided meets requirements of the building regulations.

Document L requires all replacement windows to be double glazed to meet or exceed a specific whole window energy value WER                     or grade A to G

Double glazed windows supplied by GBS meet this requirment in accordance with BS EN 673 having a whole window value of 1.5 Kw/2k, equivilant to grade C

This is achieved by using a low emesitivty softcoat glass as one leaf and a cavity of 16 mm argon gas filled with overall unit depth of 24

Document N requires safety glass to critical areas.

Critical areas are glazing below 800 mm from floor level, glazing in doors and adjacent panels. Glazing supplied by GBS meets this requirement with use of toughened glass to BS 6262.

Document B requires windows in habitable rooms to provide emergency escape known as egress .

Egress windows must provide a clear unobstructed minimum opening width or height of no less than 450 mm and a square area of no less than 0.33 M2and must not exceed 1100 mm to the opening from floor level.

Document F requires back ground ventilation of all rooms via either windows, wall vents or mechanical ventilation.

Where windows that are to be replaced are not currently fitted with trickle vents their replacements do not require trickle vents

Where windows that are to be replaced are currently fitted with trickle vents their replacement must also be fitted with trickle vents.

Where windows are supplied for new build properties or extensions trickle vents must be fitted to the windows unless some alternative back ground ventilation or mechanical ventilation is installed.

Window furniture with vent facilities may also conform to this requirement.

Certification All replacement windows require building regulation certification, it is the responsibility of the installer to provide such certification Certification will be required by future prospective purchasers of the property their surveyors, solicitors and lenders.

Non compliance of the building regulations will be in direct breach of the Building Act 1984 and or Building Regulations 2000 and may result in enforcement.

Listed Buildings and conservation areas

The considerations for easement of part L of the regulations are Historic Buildings, listed buildings and buildings within conservation areas. In such cases it would be advisable to seek the opinion of your local authority conservation officer regarding the style and glazing of replacement windows and doors to determine if Planning Consent is required before any work is carried .

Whilst every assistance will be offered to customers with a listed building or with property within a conservation area including providing specifications and indicative or individual drawings for applications, the responsibility to meet the requirements of any local authority planning requirements lies with the property owner.

We are now able to handle local authority planning applications for clients. Fees apply .


The supply only of windows and doors is subject to vat at current standard rate.

The supply and installation of windows and doors is subject to vat at standard rate, however for new build or conversion vat may be zero rated or reduced.

The replacement of windows to a listed building is classed by HM Revenue & Customs as repair and maintenance and is therefore subject to vat at the current standard rate.
  • Our new Door is exceptional , making good outside and inside all superb by Ryan who is a great asset to your company, for very hard working, attention to detail, high skill level and is and a really nice likable guy

    Mr P Stevens , Cheshire.
  • Thank you! The quality of the workmanship [For our wooden door replacement] is wonderful, and the fitting was excellent – it fits so perfectly into place, with no damage to the internal architrave or existing step. I can hardly believe it’s a replacement door. Great fitters and excellent communication throughout. I wouldn’t hesitate to recommend you

    Anna, Cheshire.
  • Please thank your craftsmen for an outstanding job. Good quality workmanship all around. Regards, Bob Screen.

    B Screen - Northwich, Cheshire
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