In heavy snow areas where you might get 5 or 6 ft.
Attic dormer high snow load.
If this rafter is supporting the dormer roof it should.
Most dormers are roof dormer windows that is the structure s roof surrounds the dormer as if it were a skylight.
In practice i found when a building only has a single valley on one side of the roof the unbalanced snow ussually governs.
And the extra heat is not just a summer concern come winter hot attic air can melt snow on the roof during the day only to refreeze when temperatures drop overnight creating ice dams that lead.
Accounting for snow loads in certain climates constructing roof dormers is relatively straightforward in both original design and renovations.
Homes in non snowy areas usually come with 20 lb.
The load path needs to flow into the rafter next to the dormer side wall.
Dormers are wonderful spots for a reading nook kids play area dressing area and other uses where extra light is a bonus.
Of snow on the roof a 90 lb.
Summer and winter photographs of the same building.
Snow accumalates in valleys and may be a major design concern.
However the side wall does not extend to the floor in this area.
When the roof was snow and ice covered that part of the roof would melt faster causing water to pond which was then wicked up by the dormer structure.
In some cases roof snow melt systems or heat tape can be used to combat ice accumulation on eaves and in valleys.
This was the cause of the long standing interior moisture issues.
In the case of heavy snow and ice during the last bad winter that s even more ponding water than usual.
Roof dormers add light.
These photos were taken by roxie baldwin in 2002 at mirror lake on the medicine bow routt national forest.
In areas where you might get 2 or 3 ft.
However only a single rafter is placed here.
If the dormer is built above living space rather than over an attic or if you re converting attic space to living space then it provides much needed natural light.
Of snow you should upgrade to the 50 lb.
Shed dormers are easier to waterproof and shed snow better than gable dormers.
Proper roof ventilation and high r value roof insulation is essential to minimizing ice dam formation.
One reason may be that the current unbalanced snow load provisions for gable roofs is much higher then what was required by some codes in the past.
