Originally Posted by signals unlimited
The vertical dimension is ok if well anchored. I would cut the mast down to all that is needed to place the antenna only as high as needed. Even if you only remove a foot of mast, you decrease the torque on the mount.
At first, I was thinking to extend the mast before I calculated the limited vertical separation. I believe you are right, mount it as low as I can and still all of the antenna elements clear the roof. It does not look like there are any antenna elements directly above the mount point. Is it important to cut the mast down as opposed to just mount the antenna lower on the mast?
I guess it is an engineering calculation balancing the shearing force a 2"x.25" wood screw will sustain before it either shears off or pulls out of the combination of a pine 1"x4" and hardieplank by the the torque exerted by the wind against the profile of the mast and antenna. I have no idea how to calculate that. Thinking about the distance between the mast mount points and the arms that extend to the eves, it does seem like that distance would act as a lever to increase the ability to resist the torque applied.
From your experience, are you aware of any general rule of thumb about the proportion of the mast that should be secured below the highest mount point of a mast?