Span Of The Roof

Shingle roofs tend to have a shorter lifespan than other options such as tile.

Span of the roof.

The average lifespan of your roof depends on the type of roofing material you have installed. Longevity depends on the climate of an area the way the original installation was handled and whether ongoing care and maintenance have been part of a regular routine. Fiberglass shingles are more. So this table could accommodate a house with a total rafter span or house width of 32 feet.

The spans in this table are based on a maximum supported rafter span of 16 feet where the supported span is the total horizontal distance spanned by the roof rafters divided in half not the diagonal distance or the length of the rafter. Visit the roof framing page for more information on cutting roof rafters and visit the roof pitch calculator for determining rafter lengths based on rise and run. The average lifespan of a roof can be affected by the slope of your home the climate where you live and the quality of material installed among other things. More importantly the lifespan of a shingle roof is greatly affected by the overall materials used.

The average lifespan of asphalt shingles ranges from 20 to 40 years depending on the manufacturer although many warranties only guarantee between 15 and 25 years.