Sunshade (Canada)

[Brad805]

We have a number of sunshades on a project. Article 45 of Commentary G of NBC suggests that a sunshade should be designed for snow loads if the spacing of the individual shades is 100mm or less. In our case the clear space between vertical shades is 125mm. The roof adjacent to the sunshades is flat, but is 19'-6" higher than the lowest level of shades. The units they would like to use are to be imported from China, so getting design data from the manufacturer is unlikely. I am having difficulty deciding what snow load to apply. Roof snow (approx 50psf), full drift (120psf max), or zero. I feel the full drift load is too conservative, and zero snow load is too low since at a minimum they will ice over during the winter. Opinions?

Thanks
Brad

 

[BAretired]

If your shades are vertical, you would not apply any snow to them because the horizontal projection of the gaps is zero.

If your frames are sloping, then consider them solid for purposes of calculating drift load.

BA

 

[Brad805]

The shade slats are vertical and are inoperable, but the unit does protrude 48" from the wall.

 

[Brad805]

re-read the clause again. I see what your point.

Thanks.