Posted By: Kevin Rose
Rafter Thrust - Math Check, Please - 02/14/10 05:53 PM
I'm calculating the rafter thrust for common rafters at 33" OC to determine how much tension will be applied at the tie beam tenons. My math yields a horizontal thrust of 712 lbs per rafter (same as the load) for a 6:12 pitch. Have I got that right?
Multiplying the total load per rafter by 11 gives a total horizontal thrust being transmitted to the top plate of 7,832 lbs. That horizontal thrust will be held by 4 bents. That means that each of the two middle bents will have a tension of 2,611 lbs at the tie beam tenon. Right?
With two pegs, each connector will have 1,305 lbs applied at full design load?
Thanks!
Multiplying the total load per rafter by 11 gives a total horizontal thrust being transmitted to the top plate of 7,832 lbs. That horizontal thrust will be held by 4 bents. That means that each of the two middle bents will have a tension of 2,611 lbs at the tie beam tenon. Right?
With two pegs, each connector will have 1,305 lbs applied at full design load?
Thanks!