[Elecraft] Attic Antenna Tradeoff?

[Ferguson, Kevin]

Most of us are just stuck with what we ended up living in,
NOW is the time to be thinking about this, Good Job!

Specify that the attic is NOT to be used for electrical, phone, CATV,
HVAC control etc. wiring, except as required for cieling fixtures etc.

 This will cost more, as the attic is the easiest place to 
run the wires. 

One of the huge problems with attic antennas is that they invariably end up
closely spaced and significantly paralell to AC wiring runs.  This couples
all the RF hash on the wires into the antenna.  Since the lines are
connected
to the grid at all times, it is not just garbage generated by a load on that
line that couples, but also from things connected several miles away.  The
more
wire you can keep out of the attic, the better.

Keeping phone, CATV lines out of the attic also avoids RFI issues. Even the
HVAC control can get RFI.  I get RFI into my thermostat if I run over 
5W on 10 meters....this turns the furnace
on and off with my keying and eventually puts out the pilot light.

Other things to think about:  

Architectural:
If you live in New-England or other areas with heavy snowfall, then the
building 
code probably requires a steep pitched roof....this is very good, as it lets
you
put your antenna higher, and you will be able to walk in the middle without
stooping. If you live in a moderate climate, then you may want a steeper
pitch
than the minimum required by code.

Insulation:
Specify that no foil-backed insulation is to be used in the house. If it is
more
than one story, such may be acceptable on the lower floors, but not on 
the upper floor.  The warning against blown-in attic insulation is valid. 
That stuff is a royal PITA.

Siding: No aluminum or steel.  No stucco (has expanded metal or chicken-wire
embedded).

Roofing: Of course steel roofs are a no-no. If using composition shingles, 
specify that the valleys are to be full-woven, with 90# felt (roll roofing) 
under them. Otherwise you will get long metal flashings in the valleys.  
I don't know of any alternative to metal edge flashing, but ask about that.

Rafters: See what it would cost to have traditional rafters fabricated on
site. 
Pre-fabricated truss style rafters are probably cheaper, but really make it 
hard to move about the attic. The jew plates at the joints invariably end up

within inches of your antenna.  There are some "engineered lumber" (wood
I-beams)
out now, that if used as cieling joists may make the cost a wash.

Specify that all the water piping should be copper (handy for grounding)

Have an attic-stair access hatch installed when the house is built.  You 
don't want to be climbing through a small trap-door on a regular basis.

Mechanical:  If possible, no metal ductwork in the attic.  If possible place
furnace and H2O heater near edge of structure instead of the middle. If the
metal vent flues go up the middle they will be in the way of everything.
Use PVC for sewer vent stacks...possibly with a short metal section where
they go through the roof.