The Fixing Specification Tool

We’ve developed an industry-first online slate specification tool designed to help architects, roofers, and specifiers create accurate, project-specific fixing specifications — quickly and with confidence.

Built around the requirements of BS 5534, the tool ensures full compliance with UK standards for slate exposure zones, headlaps, and fixings. By entering just a few project details, you can instantly generate a tailored fixing specification that’s ready to include in their documentation.

Whether you’re designing for a new build or a refurbishment, this tool simplifies the specification process, saving time while guaranteeing the precision and performance our natural slate is known for.

BS 5534 compliant – Automatically calculates correct headlaps and fixings based on exposure zones.
Fast and accurate – Generate a professional fixing specification in minutes.
Tailored to your project – Specifications adapt to your site location, roof pitch, and chosen slate.

Experience the easiest way to create compliant slate specifications.

Simply follow these steps to calculate everything you need to know about your natural slate roof. In just two clicks, you’ll get the number of slates required and the weight per square metre.

Enter the name of your project.
Select the location of your project to determine the exposure rating.
Indicate the pitch of the roof.
Choose the slate size. Remember: for projects with a pitch lower than 22.5°, Traditional Roofing Slates are not permissible under BS5534, but you can use our Readyslate product.
Select the product you want to use (you can check out our range here).

Click Calculate and you’ll get all the information about your roof! If you need more details, click Download detailed report to instantly download your personalised Fixing Specification Document.

1. Project name:

Enter your project name.

2. Region:

Select the region.

3. Exposure Rating:

Exposure Rating of the selected region:

4. Pitch:

Select the pitch of the roof.

5. Slate Size (mm):

Select the size of the slate.

6. Product Type: View products

Select the product

7. Thickness:

Thickness of selected product:

While this calculation is based on recognised standards, it is intended as a guideline only. Every roof is unique, and actual requirements may vary. We strongly recommend consulting with us or a qualified roofing professional to confirm your project’s exact needs.

If you have any questions, our experienced team on slate is at your disposal.