I’m certain this question has been asked a million times on this forum:
We performed a wind mitigation on the home shown in the attached images.
Based on my experience and training in class I’m calling out “other” because of the way the flat roof is attached to the main roof. Home owner argues its a hip roof.
I feel pretty damn confident its other because of the attachment being made on the main roof.
We still need a measurement when its attached structurally or does this automatically rule it as other because of the attachment?
Roof Geometry: What is the roof shape? (Do not consider roofs of porches or carports that are attached only to the fascia or wall of the host structure over unenclosed space in the determination of roof perimeter or roof area for roof geometry classification).
The form says to not consider porches that are attached to the wall of the host structure, doesn’t say what part of the wall (top or side). Specifically, was the roof structure for the low-slope roof system attached to the wall only? Or was it attached to the hipped-roof structure? Would it’s removal damage the main roof structure or simply detach it from the wall?
Most importantly, was the low-slope roof system located over living space? Also, the overhangs on that structure are well beyond 24", to what standard (building code) was the home built? Try it this way:
what standard was the home designed/constructed to (this is key in determining a roof structures ability to potentially mitigate wind)?
What type of roof-to-wall connection did the home have (a hip roof with toe-nail roof to wall connections isn’t going to do much)?
Was the roof covering FBC complaint (what good does it do to have a hipper roof structure if the roof covering is 50 years old)?
was the roof deck re-nailed, or required to be (you can’t give a roof structure credit for potentially mitigating wind damage of the roof deck is stapled down)?
Was any part of the roof structure damaged (damaged roof structures do not qualify for a hipped-roof classification, common sense should kick in there)?
Was the roof covering leaking (a failing roof covering should not allow a hipped-roof classification until it is repaired or replaced)?
All of these considerations are part of determining a roof structures ability to potentially mitigate wind, they make sense. The current methods being taught don’t because they are being taught by people who have little to no understanding of wind mitigation or the laws of the state. Most are simply regurgitating all of the bad habits they learned from others. There is a program within the state that can teach you proper wind mitigation (FSS 553.841), that and consulting with the Florida Building Commission will help.
Under no circumstances ask an insurer, underwriter, or the OIR how to complete the form, we have enough know-nothings doing that now.
It’s a very important question, with more than one possible answer. To fully understand what a hip roof geometry is you must know what sets a hip roof apart from other roof structures. First, it isn’t a “hip roof”, it’s a “hipped roof”. What specifically separates a hipped roof from other roof structure is the corner features. Hipped roof structures have multiple connection points at the corners that reinforce the attachment and redistribute wind loads to each connection within the corner construction.
So, what sets a hipped roof apart from other roof structures? Simply put, it is a “reinforced roof structure” at the corners. Hipped roofs are not inherently different because of their slope (slope plays a very small role in determining roof geometry for existing structures only), but because of their multiple connection points that redistribute wind loads at the corners. If hipped roof structures were the only ones that could redistribute wind loads when properly designed, they would be the only roof shapes we currently build with. But they aren’t.
This is why you still see gable wall features (concrete gable features are not technically classified as a gable end walls) being constructed throughout the state, the methods for “reinforcing” these structures for mitigation purposes is required in the Florida Building Code. A properly installed and reinforced gable end wall meets the intent of a hipped roof geometry, that it is built to redistribute wind loads at its’ interior framework. The only process for determining this would be through an inspection (OIR-B1 1802 Uniform Mitigation Verification Inspection Form).
Back in 2006 the Florida Building Commission embarked on a mission to promote mitigation (redistribution of wind forces) of existing structures in Florida. It was determined that the use of mitigation techniques on existing structures, built to codes other than the Florida Building Code, could lessen wind damages during hurricanes and protect the public. In the 2007 Florida Building Code specific methods for applying mitigation techniques to existing structures was implemented. These techniques are listed within the Florida Building Code today.
Chapters 7 and 17 of the Florida Building Code: Existing Building address roof covering, roof deck attachment, opening protection, roof to wall connection, secondary water resistance, gable end wall bracing, and roof geometry. These methods are specific in their intent to mitigate wind damages on existing structures. When followed, they are part of the Main Wind Force Resisting System (MWFRS) of a structure and complete an envelope around a structure for the intended specific purpose of mitigating wind damage.
Despite what some “Copy and paste artists” might tell you. The main thing you need to look at is if the porch roof could be torn off without damaging the main roof. in this case it can’t. So the next question becomes, how big is this roof in comparison to the main roof. Figure out if the flat roof edges come in at more than 10% of the roof perimeter. if they are more, roof is other, less, roof is hip. Unless of course there are other features you didn’t make us aware of.
