Warm Roof Nails Online Calculator

If the Site Details are unknown then

This is an estimate of the wind and snow loads based on selected location and exposure
The nearest town will give values for wind speed and snow load appropriate to the location.
Select Nearest Town
The altitude factor Sa is used to adjust the basic wind speed for the altitude of the site above sea level. It has been assumed that there is no significant topography. If you do not know the altitude of the selected location and an Ordnance Survey map is not availabel, we recommend the use of Google Earth.
Height above sea level
As a generalisation any building more than half-way up a hill, or an on a ridge or cliff will have increased wind loading.
If your project falls into this category, then a more detailed analysis will be required.
Is the building more than half-way up a hill, or on a ridge or cliff	Yes No
The town category is defined as built-up areas with an average level of roof above ground level of at least 5m. For a building to be considered as town, then the building must be at least 2km inside the town terrain. If within 3km of coast treat as country.
Location	Town Country
Distance from sea
Building height to ridge

You have stated that the building more than half-way up a hill, or on a ridge or cliff. If this is not the case click the back button.

If your project is more than half-way up a hill, or on a ridge or cliff then then a more detailed analysis will be required.

Contact David Roy at Roofconsult Limited david@roofconsult.co.uk on 01903 774907.

Building Details
Roof area on slope (m²)
Rafter centres
Counter batten thickness We do not recommend the use of counter battens less than 35mm.
Tile/sheet weight
Gap between rafter & counter batten Insulation + other materials
Roof pitch
Roof type	Mono Pitch Duo Pitch

SPECIFICATION SHEET

Project Details
Project Name
Designer
Site Details
Basic wind speed Vb	m/s
Altitude factor Sa
Terrain/building factor Sb
Site snow load so	kN/m²
Building Details
Roof area on slope	m²
Rafter centres	mm
Counter batten thickness	mm
Tile/sheet weight	kg/m²
Gap between rafter & counter batten i.e. Insulation & other materials	mm
Roof type	Pitch
Roof pitch	°
Results
Wind load	kN/m²
Permissible tensile Load	kN
Actual Tensile Load	kN
Snow Load	kN/m²
Permissible Shear Load	kN
Actual Shear Load	kN
Super-7 Nailing Details
Up-rafter Fixing Centres	mm
Fixings Required	per m²
Quantity Required
Minimum Nail Length	mm
This data is calculated using a Design Method that has been approved by the Building Research Establishment, which is applied to the results of an independent test programme carried out by CERAM Building Technology. Wind load calculations are to BS 6399:Part 2:1997, snow load calculations to BS 6399 Part 3:1988. Partial safety factors are from National Annexes to Eurocodes 0 and 5 and have been applied in respect of timber connections, dead loads, wind loads and snow loads. The results are specific to Thor Helical Super-7 Warm Roof Nails, which are guided through the counter batten and into the central section of the rafter.

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