High Wind Roof Rafter Designs

Many conventional roofing products such as shingles mandate a slope no lower than 2 12.

High wind roof rafter designs.

While this article focuses on configurations we also have a very cool set of illustrations showcasing the different parts anatomy of roof trusses. Wrap hurricane straps over the top of the roof truss or rafter. Hold down brackets are brackets that are bolted nailed or screwed to wall studs or posts and anchored to the construction below concrete masonry or wood to hold down the end of a member or assembly i e shear wall. Use baffled ridge and soffit vents to minimize the number of roof penetrations which are vulnerable in high winds.

Baffled vents slow airflow and prevent wind driven rain from entering the attic through the ridge vent. Continuing on from part 3. Bond beam depth and minimum horizontal reinforcement varies with design wind velocity ceiling height roof truss span and spacing of vertical wall reinforcement. Floor beam span tables of residential structural design we will now look at roof rafter and beam design.

Flat or actually more like nearly flat single slope think one high wall with a roof that slopes down to a lower wall. This approach conforms to my general design philosophy when in comes to the structural design of houses. The numbers vary depending on your local design wind speed zone but the bottom line is that you can use the same hardware here that you would use if the roof were an ordinary 12 pitch roof with straight rafters. Use this calculator to find your rafter length.

It helps to understand the 4 basic geometric shapes that are common to most types of roofs. More they usually claim that 4 12 is the lowest you can go without any special underlayment. Here we have a wood framed gable roof. Let s consider a basic gable wood roof framing design.

The hip style roof of this 3 bedroom 3 bath southern home plan even in low profile is a recommended roof style to resist high winds plan 136 1031. This guide is ultimately about the top 20 styles of roof designs. Rafter clips and roof tie downs are straps or brackets that connect roof framing members to wall framing to resist roof uplift loads associated with high wind conditions. Clay or concrete spanish tile is also a common roofing material in southern parts of the country and is resistant to high winds as are stone and stucco exterior siding materials.

The image below shows a cross section of our simple 12 x 13 house from the joist span tables section of this tutorial. First you ll want to find the pitch of your rafters which will help you find the length of your rafters.