cable rafter ties

[paulmars]

I've decided to add rafter ties to my home. Im thinking of using cable. 1952 house. This house was built with NO rafter ties and very few collar ties. Block construction. The joists run from gable to gable. With the nakid eye the ridge is not sagging, walls are

not bowing. However, I have added hurricane straps and gable supports. Soon, i will be replacing the roof and while at it, screwing the roof planking to the rafters. Im making my home as hurricane resistant as possible.

Therefor I have also decided to add cable rafter ties and 2x6 collar ties.

suggestions?

pa

[Erby]

You could also just use 2 x rafter ties across the tops of the joists.

Remember the collar ties are there to hold the roof down, not keep it from sagging. That's the job of the rafter ties.

[Marc]

What Erby said. Forget the 2X6 collar ties. 1X4s are fine, 4 feet apart.

Use this checklist to improve the resiliency of your home to hurricane-force winds. It's the smart move.

Don't try to self-engineer. That has already been done and the methods are available to any owner of a wood framed structure.

Marc

[Jim Katen]

Sounds like a plan.

Don't use drywall screws. Use Simpson SDS screws.

What kind of cable will you use? How will you connect it to the rafters? Will you use one cable for every set of rafters?

[paulmars]

Sounds like a plan.

Don't use drywall screws. Use Simpson SDS screws.

What kind of cable will you use? How will you connect it to the rafters? Will you use one cable for every set of rafters?

aircraft

dont know.

4' oc

[Steven Hockstein]

Use info from this section of IRC 2009

R802.5 Allowable rafter spans. Spans for rafters shall be in accordance with Tables R802.5.1(1) through R802.5.1(. For other grades and species and for other loading conditions, refer to the AF&PA Span Tables for Joists and Rafters. The span of each rafter shall be measured along the horizontal projection of the rafter.

[mjr6550]

what is the roof pitch and the distance from wall to wall that support the rafters?