Modified Bitumen Roof Minimum Slope

Modified bitumen roofing minimum roof slope roof pitch r905 11 1.

Modified bitumen roof minimum slope.

One of the longer lasting roofing options for flat roofs is bitumen roofing or a modified bitumen roof. Thermoplastic polyolefin tpo single ply roofing membranes are typically offered with 20 year warranties but manufacturers are now on their sixth formula iteration and have yet to effectively resolve cracking erosion and other. Modified bitumen roofing may have a granular surface as shown here or it may be smooth. Bitumen roof advantages and disadvantages.

Modified bitumen membrane roofs must have a design roof slope of 1 4 12 or greater 2 slope. These steps show a torch down method which looks a bit scary but actually is not too difficult. Technically we are talking about low slope roofs that have a slope less than or equal to 3 12. This means for every 12 horizontal units the roof must rise a minimum of one fourth vertical unit.

Renting a large propane torch is inexpensive. For example the international building code 2018 edition ibc 2018 prescribes a 1 4 12 minimum roof slope for asphalt built up polymer modified bitumen thermoset and thermoplastic single ply and liquid applied membranes in new construction. This 1 4 12 minimum roof slope requirement also applies to spray polyurethane foam spf roof. You can read our article about calculating slope for information on the various roof slope notations.

Advantages there are a wide range of methods available for installing modified bitumen roofing from using a hot torch to using a sealant backed peel and stick rolls. The following table provides the minimum required allowable roof slope for each type of roofing material mentioned in the code. Tamko modified bitumen roof system over wood decks miami dade county noa 17 0222 09 expiration date. Modified bitumen roofing was designed for use on buildings that have a low slope or flat roof.

Liberty sbs self adhering base ply sheet is a self adhering roofing membrane designed to be used as either a base sheet or a ply sheet in your modified bitumen roofing system providing long lasting protection for low slope roofs. Tamko modified bitumen roof system over steel decks miami dade county noa. The minimum slope for a flat roof is 1 4 per foot or 1 4 12 but some owners or insurance companies require a minimum slope of 1 2 per foot. Limited warranty 5 year limited warranty.

Self adhered modified bitumen roof systems come with several advantages over tpo single ply roofing systems.