Residential Flat Roof Loading

Most modern residential homes have relatively steep pitches.

Residential flat roof loading.

For ground snow loads greater than 20 pounds per square foot the roof load is equal to 70 of the product of the exposure thermal and importance factors the ground snow load and 20 pounds. There s a lot to know about flat roof systems and how they. 2018 international residential code. Contains sections covering roof framing roof sheathing and roof ventilation.

Flat roofs make replacing a roof a challenge. Cities with older housing stock think federal hill in baltimore or alexandria virginia s old town the roofs are often flat or have very low slopes. All three types of flat roofing cost 250 to 350 per square 100 square feet but prices vary according to region and size of the roof. Also known as low slope roofs flat roofs are less common in north american residential construction because the low slope of a flat roof has an increased tendency to collect water rather than shed like its more steeply pitched alternative.

Flat roofs usually come with a 10 to 20 year warranty but can last 25 years if you build the roofs right and maintain them using commonsense rules. There are several things to consider when choosing a flat roof such as the materials weather and maintenance. However in many u s. On the upcodes website.

Built up roof bur the traditional hot tar and gravel. For roofs that are flat and with ground snow loads lower than 20 pounds per square foot the roof snow load is equal to 70 of the product of the exposure thermal and importance factors and the ground snow load. This would be the ceiling materials under the roof and any permanent installations such as hvac components. Flat roofs are usually found on commercial buildings rather than residential buildings but this does not mean you cannot have a flat roof constructed on your home.

The load increases with the use of heavier roofing material. Flat roof systems are a bit of an outlier. Chapter 3 design loads for residential buildings. For a larger map with greater detail refer to asce 7 98.

This includes the combined weights of all of the individual roof materials and anything attached to it permanently. As an example of what you can find in chapter 8 of the 2018 irc see. This may make it less ideal for rainy or snowy climates. A clay tiled roof may have a dead load.

2018 international residential code. Location 2uniform load psf kn m roofs ordinary flat pitched and curved roofs roofs used for roof gardens roofs used for assembly occupancies roofs used for other occupancies awnings and canopies fabric construction supported by a skeleton structure screen enclosure support frame all other construction schools classrooms. 3 20 residential structural design guide. In areas where the ground snow load is less than 15 psf the minimum roof live load refer to section 3 4 is usually the controlling rgavity load in roof design.