|
The InSkews require a minimum 35mm penetration into a softwood rafter.
| Counter batten thickness |
38mm |
| + |
+ |
| Insulation thickness |
50mm |
| + |
+ |
| Optional ply deck |
Nil |
| + |
+ |
| 35mm into the rafter |
35mm |
| = |
= |
(Rounded up to nearest standard length) |
Helifix is the only manufacturer to have had independent testing carried out on its roof fixing. Initially TRADA carried out comprehensive testing and developed our original load tables. These were updated in 2000 to conform to current timber standards and measure performance with deep insulation.
In 2003 Napier University conducted timber pull-out tests which concluded that three traditional fixings would be required to match the performance of a single InSkew. Comparative costs should bear this in mind – together with the labour costs of installing three times as many traditional fixings.
As insulation thicknesses increase so does the need for ever longer effective fixings. Whereas nails increase in diameter and tend to curve as their length increases, InSkews remain constant in diameter and are straight. Traditional fixings will therefore require wider, and more expensive, counterbattens and rafters as their length increases to avoid splitting the timber – a problem InSkews avoid with their self-tapping helical design.
For a detailed and accurate fixing specification that takes into account your exact roof details and specific location, which will save you time and money and is covered under the Helifix Professional Indemnity insurance, please call our Technical Sales Team on 020 8735 5222. |
A. Counterbattens must be at least 25mm thick to grip the tile batten fixing firmly.
B. Insulation over 50mm thick requires a stop batten.
C. Hand or power support tools should be used with InSkews of 120mm or longer. The power driver speeds installation and is recommended for deep insulation and to reduce buckling when driving into hard rafters.
D. When using InSkews to fix tile battens to support vertically hanging tiles, contact the Helifix Technical Sales Team.
Helifix is happy to provide individual project specifications to suit your exact requirements. You can either visit our website (www.helifix.co.uk) and complete the InSkew 600 Enquiry Form on-line and email it to us, or you can telephone our Technical Sales Team on 020 8735 5222. When telephoning please make sure you can provide the following information to enable us to work out an accurate specification.
1. Counter-batten thickness
2. Insulation thickness
3. Additional material thickness (e.g. ply deck)
4. Counterbatten/rafter centres
5. Roof pitch (rounded to the nearest 10°)
6. The laid weight of tiles or slates being used
7. In which county is the site?
8. Wind exposure – minimum, medium or maximum?
9. Is the building over 15m high?
10. The area of the roof in m2 |
|
