Gable ends probably present the most complex glazing scenario because of the numerious angles and mid rail intersections.

Carpenter Oak & Woodland have been glazing oak frames for over fifteen years. Glazing onto oak frames requires a specialised glazing system and experienced skilled craftsman. Only then can you ensure years of trouble free service.

We have an unsurpassed record for the quality of our workmanship and support it with a full 3 year warranty on materials and labour and manufacturers 5 year warranty on the glazing units.

The glazing system

Because the timber in an oak frame moves as it dries the glazing system must accommodate this if it is to remain wind and weather tight. In the early 90’s we developed a ‘drained and vented’ glazing system through discussion with Pilkington Glass. One of its key principles is that it assumes that water will in certain conditions (particularly driven rain and wind buffeting) make its way past the first seal and as such must be allowed to free drain away from the timber frame. The second seal is then able to provide full wind and weather tight integrity. Systems that don’t allow for this, particularly those that use silicone mastic will inevitably trap water against the frame which will lead to the onset of rot.

The success of the system is dependent on a number of key things -

• the selection of timber in the frame onto which the glazing will be applied
• the quality of the materials used in the glazing system
• the preparation of the oak frame
• the skill of the installers

Glazing to an oak framed extension

The materials

Our glazing system is applied to the outside of the frame to create a wind and weather tight ‘envelope’ and prevent risk of damage to the glazing units and the frame as it shrinks and moves.

Our glazing system comprises:

• Glazing units – we use toughened, argon filled glazing units with a high specification U-value of 1.2 w/m k bedded onto EPDM black rubber glazing tape to provide the flexibility needed to accommodate the movement of the green oak frame.
• External oak cover boards – each unit is secured by an external joinery grade seasoned oak cover board fixed back to the main structural frame creating a wind and weather tight envelope outside the frame. The cover boards have a sawn finish so that they emulate the frame. Beware of using cheap timber for the cover boards as the wrong cut of timber will ‘cup’ badly, cause leakage and damage to the glazing units.
• Fixings and flashing – in order to ensure longevity of service we only use high quality materials including larch packers, stainless steel fixings and 24swg copper flashing. Beware of cheap alternatives; the iron in steel screws will react strongly with the tannin in the oak and will deteriorate very quickly. Lead flashing will corrode as the tannin from the oak is washed over it by the rain.
• Installation – our price includes all the appropriate lifting and access equipment, haulage of materials, travel and accommodation costs and site labour.

Glazing an oak framed building depends on meticulous attention to detail

Common questions

Are there alternative systems?

The most common alternative is to set the glazing into a rebate in the frame and apply a bead to the external face. Installers using this system normally apply the glass onto silicon mastic. Whilst it is quicker to install and uses cheaper materials it is prone to failure as the timber shrinks away from the glass and water becomes trapped against the valuable oak frame. It is unlikely to have a 3 year warranty.

Will you fit your system to other manufacturer’s frames?

We will as long as the frame has been manufactured to a high standard. Importantly the timbers onto which the glazing will be applied must meet the required specification with minimal knots and slope of grain. This is essential because these characteristics cause deflection in the timbers as they dry out and are the biggest cause of water ingress and damage to glazing units.

What are the benefits of Carpenter Oak & Woodland system?

• It accommodates movement and shrinkage of green timber
• It is a drained and vented system that guarantees water tightness even in very demanding weather
• It allows for easy replacement should a unit get broken
• It comes with a 3 year warranty on the system and 5 year manufacturer’s warranty on the units

Our service to frame manufacturers

Our oak frame glazing system has been developed to give you and your customer’s piece of mind and comes with a full 3 year warranty with the manufacturer’s 5 year warranty on the glazing units.

This is a proven system developed in collaboration with Pilkington Glass and available for installation across the UK. We use high quality materials and our dedicated glazing team only work on green timber frames as such they have a full understanding of the issues associated with timber movement and deflection.

For more information about glazing onto oak frames download Glazing Green Timber Frames with Carpenter Oak & Woodland (pdf 604Kb).

For a detailed quotation please contact us on 01225 743089, fax a set of scaled frame drawings clearly indicating glazing units and if appropriate associated joinery to 01225 744100 or email the details to paul.kersey@cowco.biz