[Elecraft] Mounting vertical antennas

[Per von Zweigbergk]

I live in an apartment building in a large city, and I have decided 
that basically the only realistic option (besides operating with 
stealthy wire antennas) is to mount some form of vertical HF antenna -- 
and I need to pitch the idea to my landlord, who will obviously have a 
few concerns. I'm probably happy enough to accept that if I do things 
"as they are normally done", bad stuff won't happen -- but it'd be nice 
to have some nice pictures, stories and hard specifications rather than 
vague ideas to put forward.

It would be really helpful if I could get descriptions of how *you* 
have mounted your HF vertical antenna to your roof, and how reliable it 
has been with respect to winds et cetera. Even more helpful would be 
pictures of the installation in place!

I'm currently leaning towards having some kind of chimney mount, since 
I won't be allowed to make any holes in the roof itself, but I'm open 
to other suggestions of course! :-) But I still have some unresolved 
questions.

How can ensure reasonable reliability. Obviously, the last thing I want 
is for the antenna to come loose and come crashing down on some poor 
soul or his car. What calculations should I do in order to ensure that 
the antenna stays up? And how can I accomplish that if it fails, at 
least it should fail in a relativelty safe way. (I.e. not come crashing 
down tens of meters. :-)

Also, most guides I've read tell you to mount the antenna to a mast 
tube, using U-bolts to secure the antenna itself to the mast. (It seems 
that my vertical has holes supplied for just that purpose.) Won't that 
decrease reliability -- should I try to mount the antenna directly to 
the chimney, or is the mast tubing there for a good reason?

Finally, should I just forget about trying to do this myself, and have 
it professionally installed? After all, the stakes with respect to 
reliablilty and safety for working at relatively high altitudes are a 
bit higher than erecting a horizontal dipole in a couple of trees 
(which I have done at my summer QTH I might add. :-) What kind of 
people can I expect to have to contact about this, and if I decide to 
go professional, how much would it cost reasonably?

-- 
73 de SM0YUF
Rig: Elecraft K2 -- Serial number 4291 (base model -- almost, but not 
quite finished.)