Snow Drift on sloped parapet
Snow Drift on sloped parapet
(OP)
Does anyone know how to calculate snow drift behind a sloped parapet structure? I have an existing building that is being remodeled and they are adding a 6' tall parapet to the front. However they are kicking back to the flat roof structure and are going to roof over the kickers to create a slope. It seems logical to me that there would be a greater accumulation of snow at the transition from flat to sloped but I can't find anything that defines what that might be.






RE: Snow Drift on sloped parapet
Depending on how steep/tall the slope was, I may just calculate the drift as if the sloping knee wall wasn't there (using the full uniform snow and full drift height). Depending on how the knee wall is framed, you may have problems with your deck at the location where the knee wall meets the sloping roof.
RE: Snow Drift on sloped parapet
RE: Snow Drift on sloped parapet
RE: Snow Drift on sloped parapet
Also, I thought there was a provision that stated that you could eliminate sliding snow if there was an obstruction blocking the snow from sliding.... like more snow. This may be in the commentary of the code (which I don't currently have).
In this case you might not have the sliding snow condition... in fact, you may not even have drift (depending on how much ground snow you have at your location).
However, you have to remember that if you parapet is made out of lt. ga. members, that you may have a line load at the end of your sloped kneed wall. The members will carry the load back to their supports which will be the back side of the parapet and the end of the sloping roof.
This is a little tricky, but if you use common sense and some engineering judgment then you should be fine.
RE: Snow Drift on sloped parapet