One inbox, read by a person. Corrections to the calculators go to the front of the queue.
Email: collaborationdesk@gmail.com
Send us a message
The quickest way to reach us. We aim to reply within two working days.
Report a wrong number
Tell us the tool, the values you entered and what you expected. We check it against the published formula and fix it the same week.
Request a calculator
If you keep working something out by hand, we would rather build it. Describe the job and the inputs you would have to hand.
Corrections to code figures
Codes get amended. If a minimum slope on the site is out of date, send the section reference and we will update it and note the date.
Partnerships and press
Embedding a calculator, licensing the charts, or writing about the site. Same address, just say which in the subject line.
Before you write in
A few things we get asked often enough to answer here.
The pitch gauge is not reading anything
It needs three things: a phone rather than a desktop, an HTTPS connection, and permission to use motion data. On iPhone you must tap Start gauge first, because Safari asks before releasing sensor data. If you declined once, re-enable it under Settings, Safari, Motion & Orientation Access. Desktop browsers have no tilt sensor at all, so the manual entry box is the intended route there.
My result does not match another site
Usually one of two things. Either the other tool is rounding the angle before using it in a second calculation, or it is quoting a rafter length that already includes or excludes the ridge deduction and overhang differently from ours. Every tool here states which measurement it is giving you. Send both numbers over and we will tell you which is which.
Can I use your charts on my own site?
The underlying maths is public domain, so nobody owns the fact that 6/12 is 26.57 degrees. Our specific tables, wording and tools are ours. Ask and we will usually say yes, with a credit link.
Do you offer roofing services?
No. We build calculators, not roofs, and we cannot recommend a contractor in your area or quote on a job. For anything structural, speak to a licensed roofer or a structural engineer.
Urgent structural concerns
If you are worried a roof is unsafe, sagging or has failed, do not email us and wait. Contact a structural engineer or your local building authority straight away.