Optimum Roof Overhang

If the building element bears more than about 30 off true south the effectiveness of an overhang as with any solar feature begins to decrease significantly.

Optimum roof overhang.

Geometry of overhang separated from top of window. Those larger than 2 feet wide have to withstand very high uplift so they should be engineered. How roof overhangs work. 24 dec 2012 02 45 pm.

Borst passive solar roof overhang design calculator. The size of the window width and height and the window s relationship to the roof the space above the window influences the direct. For high wind resistance use 7 16 inch or 19 32 inch plywood or osb roof decking attached with nails not staples. The optimum depth varies with the latitude and the type of climate.

An important component of passive solar design is calculating building openings doors and windows and roof overhangs. You can use the free software sketchup to draw the house and it will draw sun shadows for any date time at your location. Roof construction and materials considerations roof decking. Doing so keeps basements and crawlspaces dry and it also helps to.

But are they really necessary. Figure 2 illustrates how this is possible. Roof overhangs should be no more than 2 feet wide. Oversized overhangs can increase the risk of roof or truss uplift.

Roof overhangs at the eaves and rakes protect the walls below from rain and sun. Optimum overhang dimensions for energy saving 295 sun fig. Overhangs are most effective for south facing elements in the northern hemisphere and at midday. For instance several features of a window will influence gain of solar heat and shade.

Roof overhangs a roof overhang is a simple architectural feature which can be used on the south side of the house to block direct sunlight in summer without reducing the available sunlight in winter. They are essential for framing and shading windows reducing splashback and getting rain to fall far enough away from the foundation. Borst engineering construction llc competence integrity and professionalism are integral to all that we do. Jonr senior member posts 5341.

Roof overhangs might look relatively routine but there is a lot of design thinking that goes into creating the optimal dimensions for each one. Because the sun travels a higher path in the sky in the summer than in winter the overhang blocks. There isn t general rules to size an overhang.