Use our Heli Calc Calculator to work out how many you will need plus the spacings - Click Here

What Are Warm Roof Fixings?

Warm roof fixings are used in over-rafter insulation systems to secure counterbattens through rigid insulation boards into timber rafters. In pitched warm roof construction, insulation is installed above the rafters to improve thermal performance and reduce thermal bridging.

Super-7 helical warm roof fixings provide a structural connection between counterbattens and rafters without compressing the insulation layer.

How Super-7 Helical Fixings Work

Manufactured from stainless steel and engineered with a patented precision helix, Super-7 fixings rotate as they are driven into timber. This corkscrew action reduces splitting and minimises bounce during installation.

The helical design provides:

• High withdrawal resistance

• Excellent holding power in timber rafters

• Enhanced resistance to bending

• Long-term corrosion resistance

With a cross sectional area more than 20 percent greater than Inskew 600 type helical nails, Super-7 delivers increased structural performance when fixing deep insulation between counterbattens and rafters.

Fixings for Celotex, Kingspan and PIR Insulation

Super-7 warm roof fixings are suitable for securing rigid PIR insulation boards such as Celotex, Kingspan and Eco-Therm in pitched warm roof systems.

They connect counterbattens directly to rafters through the insulation layer, maintaining structural stability while supporting tiled or slated roof coverings.

Compliance and Structural Performance

Super-7 warm roof fixings have been independently tested to meet NHBC technical requirements when specified using HeliCalc.

HeliCalc is a BRE approved design method that calculates correct fixing size, spacing and quantity based on applied wind loads and bending moments. Calculations ensure compliance with:

• BS 6399 Parts 2 and 3

• Applicable Eurocodes

• NHBC standards

HeliCalc calculations are based specifically on the performance of genuine Thor Helical Super-7 products.

Selecting the Correct Fixing Length

Warm roof fixings are available in lengths from 130mm to 240mm in 10mm increments.

Correct length depends on:

• Insulation thickness

• Counterbatten depth

• Required embedment into the rafter

• Wind uplift requirements

Use the HeliCalc design calculator to determine correct size, spacing and quantity for your project.

Installation Guidance

To ensure correct installation:

• Fixings must be driven vertically into the centre of the blind rafter

• An alignment tool should be used to maintain correct positioning

• Spacing should be determined using HeliCalc

Proper installation ensures structural stability, load transfer and long-term performance of the pitched warm roof system.

Product Details

• Stainless steel construction

• Patented precision helix design

• Suitable for pitched warm roof systems

• Pack size: 50

• Lengths: 130mm to 240mm (10mm increments)

FAQ Section

How many warm roof fixings do I need per square metre?

The required number of fixings depends on wind load, insulation thickness and roof pitch. Use the HeliCalc calculator to determine the correct density for your project.

What length fixing do I need for 150mm PIR insulation?

The correct length must allow for insulation thickness, counterbatten depth and sufficient embedment into the timber rafter. HeliCalc provides a project-specific recommendation.

Are these suitable for timber rafters only?

Yes. Super-7 warm roof fixings are designed for use in timber rafter constructions in pitched roof systems.

Do warm roof fixings compress insulation?

No. These helical fixings are specifically designed to secure counterbattens without compressing the insulation layer between the batten and rafter.

Are these compliant with NHBC standards?

Yes. When specified and installed using HeliCalc calculations, Super-7 fixings meet NHBC technical requirements and relevant British Standards.