Minimum Flat Roof Overhang

Overhangs are common in most house designs providing protection against both wind and rain.

Minimum flat roof overhang.

Weather and not properly protected by a roof eave or similar covering table r802 11 required strength of truss or rafter connections to resist wind uplift forcesa b c e f pounds per connection r804 3 2 1 1 eave overhang. Eave overhangs shall not exceed 24 inches 610 mm measured horizontally. Of course it is common in the philippines to build the overhangs larger so to keep the sun off the concrete walls. We are building the roof and want to create an overhang that acts as a bit of a canopy above a bi fold door to shield it a bit from rain.

The ibc table 1505 1 lists the minimum requirements for roof covering fire resistance classifications a b or c for all types of. The larger the overhang the more upward lift will be created on the roof. The length of the overhang depends primarily on the climate. If the roof overhang is not big enough then the only way to protect these windows doors and entryways is by recessing them into the thick exterior wall or by installing special casing and flashing for each door or entryway.

This is a compromise you will have to think about the larger the overhang the more pressure your roof will have to withstand. However you can only use this pitch with built up roofing or specialized synthetic roofing. The siding underneath the overhang is known as the soffit. The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run.

Figure r804 3 2 1 2 gable endwall overhang. When required testing is in accordance with astm e108 or ul 790. We are using 9x2 joists for the span but these will be notched down to 5 for the overhang. Does anyone know what the maximum overhang can be for a flat roof construction depending on joist size.

In general roof overhangs offer an effective solution for how to protect windows doors and entryways. Metal is usually installed on rafters or strip sheathing rather than the solid decking used under other materials. Some slight overhang is recommended in conjunction with a drip edge flashing to prevent water from getting under the roofing and onto underlying wood. Roof overhangs are the amount that the roof hangs over the top of the siding in residential home construction.

Minimum roof fire resistance ratings apply based on the type of construction and some building types do not require a fire rating.