Snow Drift at interior corner of a low roof

[stevenspm]

Hello,
I have a question about snow drifts. I am designing a building that has three different roof heights meeting each other, please see the attached. For the area that I have circled should I combine the drifts off the other two roofs or should I take just the worst case to design the joists. Please note I am changing the joist layout on the smaller roof from what is shown (it was done that way for illistrative purposes.)

Thanks,
Phil

 

[DETstru]

See the attached document for how to deal with intersecting drifts.

 

[RHTPE]

Agree with DETstru and the attachment.
In my words:

From my perspective in New England, assuming N-S direction parallel to the numbered grids, with North being towards the higher lettered grids:

Consider the greater of:
1. leeward drifting from wind out of the North, accumulating along line H to the South.
2. leeward drifting from wind out of the East, accumulating along line 6(?) to the West.
3. a combination of the 1 & 2 will give overlapping triangular loading at the inside corner with an upper magnitude equal to 1, but not additive of both 1 & 2, consistent with DETstru's attachment.


Ralph
Structures Consulting
Northeast USA

 

[stevenspm]

Thanks for the information.

Phil