Well, if you live in Texas, you need to know how often to replace your roof.  If you have an asphalt shingle roof, the average life of such a roof is about 15 to 25 years.

But pay attention to several factors that could decrease its lifespan.  Having proper ventilation is an important factor.   A poorly ventilated roof can age faster.  The slope of the roof and the specifications of the shingles and roofing material must match.  If a roof has a shallow slope, the need for keeping out the slower moving water is higher than that of a steeper sloped roof.