Coefficient of Friction on Roof
Coefficient of Friction on Roof
(OP)
I'm checking sliding (due to wind) of a temp. guardrail system on a membrane roof. The bases are coated with rubber, so it's rubber on rubber, but could be wet. I'm looking for opinions on a value for the coefficient of friction. Thanks.






RE: Coefficient of Friction on Roof
And i would be more worried about the fact it is a guardrail that is not connected to anything... doesn't seem like a guardrail.
RE: Coefficient of Friction on Roof
RE: Coefficient of Friction on Roof
Eric - Depends on duration of temporary, but, in my opinion, winding loading should be looked at for temporary structures. In this case, it will be approaching permanent installation.
RE: Coefficient of Friction on Roof
I would consider that approximate at best. Actual sliding could involve rocking back and forth moving a bit at a time or something like that rather than just a smooth motion.
A little sand thrown in there may reduce the COF as well.
RE: Coefficient of Friction on Roof
I again reiterate my earlier statement that the overturning effect of any lateral load (OSHA 200# or your 12plf wind) will negate the friction factor unless your railing is so heavy that (200*3.5' = 700 ft-lb) 700 ft-lb of moment can be resisted without permanent anchors. At which point you will crush all the insulation below the EPDM/TPO/PVC membrane and possibly compromise the structure.
But maybe this is a system that i cannot imagine and you are 100% correct, Very possible!