FAQs

Here at Lynx Trussed Rafters, we pride ourselves on being a professional, experienced and friendly team. We have served UK customers for over 30 years and understand the process from creating specific designs and supplying them for commercial and domestic use. Each customer is important to us and we make sure that we achieve, and you receive the highest quality standard of service and produce.

There is no mandatory requirement to treat timber used in the manufacture of trussed rafters in most of the UK. The exception is an area of the South East where insect damage from the Long Horn Beetle requires the use of treated timber.

The majority of trussed rafters manufactured in the UK are fabricated using European Whitewood which has been kiln-dried to a moisture content of 12% and machine stress graded. The most common grade used is TR26 which is a specific grade for truss manufacture. 

Common timber width for trusses is 35mm for truss spans up to 11.0m and 47m for spans greater, although there are other thickness restrictions for longer spans.

There is no mandatory regulation that requires the use of a metal clip connection, although the British Standards and the Trussed Rafter Association strongly recommend the use of preparatory mechanical connection between the truss and the supporting structure. The main purpose of the connection beyond simple positioning is to resist uplift forces generated by wind. 

Skew nail is a method of connection often seen but isn’t recommended. It is extremely difficult to apply proof calculations to a pair of skew nails and there is often a risk of damage caused to the nail plate on the eaves joint while hammering home the skew nails.

Glide shoes fitted at the bearing points of trusses allow a limited amount of horizontal displacement of the truss at the bearing. The raised tie design leads to flexing of the extended rafter members and as the truss tries to deflect this, a horizontal force is generated at the bearing points. If the bearings were rigidly fixed to the truss, this force would then result in damage to the supporting structure and decoration. By introducing a sliding bearing mechanism like the glide shoe, the amount of horizontal force transposed to the wall is greatly reduced and minimises the potential for structural damage.

Unless otherwise stated, all carpenters metalwork should be fully nailed using the special square twisted nails supplied. Other nails, such as plasterboard nails should not be used and could result in failure of the connection.

Lynx Trussed Rafters have been accredited The Programme for the Endorsement of Forest Certification (PEFC). This gives our customers reassurance and confidence that timber products supplied by us are sourced from responsibly managed and sustainable forests.