Ground snow load pg.
Solution to roof snow drift.
The first reason to worry about roof snow is you re worried about a roof collapse.
Figure 7 1 pages 84 85 and table 7 1 page 92.
A longer term solution to drifting snow includes building up roads and driveways so that snow is blown across rather than drifting on to them.
Usually the roadway should be 1 2 feet higher than the nearby landscape to make this effective.
This approach is conservative and simpler but for small gap the width could be 6 hd.
For ordinary leeward drifts the width is 4hd unless hd hcin which case we set the height at hcand increase the width.
Determine the direction from which wind usually moves the snow.
Solutions to these problems are generally self evident e g place air intakes high up on the wall keep windows at roof steps as high above the lower roof as possible locate plumbing vents and.
A sloped metal roof system can be installed directly over the lower flat roof minimizing business disruption.
From our example our ground load and flat roof snow load were found to be 30 psf and 21 psf respectively.
Lets assume our project is in madison wisconsin and we have already calculated our balanced roof snow load here.
Perhaps the least costly option is to institute a snow drift monitoring program after a significant snow or winter wind event the roof could be inspected to look for snow drifts at known susceptible areas.
This is fairly simple to determine even when it isn t snowing.
Length of roof upwind of the snow drift.
Table 1 1 page 3.
The second reason is you live in an ice dam prone home and you want to prevent ice dams.
Length of high roof lu.
To prevent a roof collapse the slope of your roof makes a huge difference.
For adjacent drifts we do not start with 4 hdand then possibly increase the width we start with the 1 on 6 shade line.
Sloped retrofit metal roofing solution for lower roof abrasive roofing materials asphalt shingles or aggregate surface build up membranes do not shed snow as well as slippery surfaced standing seam metal roofing.
Before building a barrier to prevent the build up of snow drifts such barriers are typically called a snow fence you must assess the area where the snow drifts.
