Rise
Raised Heel Truss
Raised heel trusses are a type of engineered roof truss that creates more space for insulation around the perimeter of an attic. They are similar to a typical roof truss, but a vertical 'heel' is installed to raise the height of the top chord above the bottom chord and the perimeter wall plate.
Raised heel trusses are typically custom engineered and fabricated, so make sure that the heel height is large enough for sufficient insulation. For attic insulation types such as blown cellulose and fibreglass, at least 16 inches are required to achieve an insulation value of R-50; however, other types of insulation with higher R-values such as extruded polystyrene can be used around the perimeter to achieve the same effect with a lesser heel height. Note that a ventilated attic will also require an additional 1 inch space to install attic baffles.
Compared to standard trusses and hand framed roof systems, raised heel trusses can provide additional room for insulation in an attic. As well, perimeter attic insulation can increase the durability of a roof system by preventing ice damming from occurring.