Physics Van 3-site Navigational Menu

Physics Van Navigational Menu

Q & A: roofing friction tests

Learn more physics!

Most recent answer: 11/18/2014
Q:
I have been testing a variety of roofing material samples for relative slip resistance using various boot outsole materials at various roof pitches. Why do my live applied load tests out perform my identical dead load tests by as much as 77% when all conditions and test methods are otherwise identical. Thanks for any input. Chip Macdonald Best Safety LLC
- Chip Macdonald (age 68)
Cambridge, NY, USA
A:

That's a very interesting question, maybe beyond our range. When you say "live applied load" does that mean a person standing on the material? If so, I bet that the person adjusts the distribution of weight between their feet and also the angles of the feet. That should help avoid slipping. Anyway, that's my guess and I'm sticking to it until you explain why it's wrong.

Mike W.


(published on 11/18/2014)

Follow-up on this answer.