Good Roof Grade
4 76 8 33 grade.
Good roof grade. Steel copper and zinc also carry their pros and cons. Pitches of less than 2 12 are considered flat roofs even though they may be very slightly angled. In this guide we ll cover the following most common roofing options. There are advantages and disadvantages to having a steep pitch versus a shallow or low pitch.
A 4 12 pitch being 4 inches of vertical rise over one foot or 12 inches of horizontal run. 3 12 1. Common roof slopes expressed in rise run and angle slope expressed as grade. The most commonly used roof pitches fall in a range between 4 12 and 9 12.
Pitches above 9 12 are very highly angled and are designated steep slope roofs. Simply put pitch is expressed as rise over run just as the grade is simply this fraction expressed as a percentage. Copper roofing pros cons the grandfather of metal roofing copper roofing has been used for centuries around the world. With regards to the pitch the building standard code bs 5534 recommends a minimum pitch of 200 for slate roofs.
However from the wind uplift mitigation perspective a 7 12 roof slope can be considered as a two story building due to the higher overall steepness and profile of the roof. And it weighs about the same as asphalt so there s no need to beef up the. Asphalt shingles wood shingles and shakes metal roofing concrete clay and fiber cement tiles natural and. Asphalt shingles are easy to install last anywhere from 10 to 50.
Roof slope expressed as an angle. 0 12. This composite material looks like the real thing even close up but costs a lot less. Roofs are framed with rafters or trusses which are rafters joined by internal braces so they install as a single component.
The minimum plywood for roofing. But since there is still a wide variety of slate roofing systems there are occasions when the minimum pitch can go down to as low as 15 0 depending on the uniqueness of the roof. For cr s roofing tests we focus strictly on asphalt roofing shingles because they re by far the most common choice for roofs. A roof slope of 7 12 is also good and can provide the additional benefit of helping minimize the effects of wind driven rain.
Easy to walk on. Pitches lower than 4 12 have a slight angle and they are defined as low slope roofs. 0 or 180 0. In roofing it is expressed in inches of vertical rise over inches of horizontal run.
Roof slope expressed as rise run in inches.