[TowerTalk] 40 foot tied to the building

[Stan Labinsky Jr.]

Hello all;

I'm looking at attaching about 40 feet of Rohn 25 or 45 topped with a VHF gain monopole antenna, which is probably about another ten feet tall.

I'm planning to attach the tower to the side of a two story concrete block building with a one story bumpout on one side.  I'd be installing the tower on the first story roof, using the second story wall to tie to.

I can make one attachment at about one half foot up and the other at the six and a half foot point of the bottom section, keeping a few inches of clearance to the roof surface to keep from causing leaks due to the tower wearing through the rubber roof seal.

Besides taking care to spread the loading of the wall with some 4 foot long pressure treated 2x6s both inside and out, is there anything else structurally that I need to look out for?  While three sections of tower would be less of a load on the wall than four, I need the height, but am I "pushing" it at four?  Would the 25 be sufficient for the job?
Also, would it be wiser to allow the tower to rest on the roof surface with some suitable wood blocks to spread the load and protect the roof surface?

I've looked around on the net and tried to find answers on the Rohn site, but to no avail, so, I'm asking those who've been there.

Thanks for your help, Stan