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However, if cost savings or limited space require it, a
properly guyed base mount will usually work. Unlike
a chimney mount, a base mount holds the mast at
only one point, the bottom. Consequently, the mast
also must be supported by guy wires, regardless of
the mast length.
Correct installation of either type of roof mount
requires great care and should not be attempted
without a helper. Both types of mounts should be
secured to the roof with either bolts or lag screws.
These should be screwed into only solid wood like a
rafter or a truss section. You can locate these with a
stud finder.
If you must fasten the mount to the roof in an area
where a bolt or screw cannot reach a rafter, send your
assistant into the attic with a large square of wood
1-1/2" thick, to act as a backing plate. Have him hold
this wood against the entry points of the screws or
bolts so that the mount is firmly anchored in both the
roof sheathing and the wooden block. This will give
the mount needed stability.
When installing a base mount, attach the base
plate to the roof in the manner just described,
and place the mast (with antenna, guy ring, and guy
wires attached), into the U-bolt that has been
fastened loosely to the mount. Do not let the bottom
of the mast touch the roof; it may tear a hole in
the shingles.
Fig. 4-10. The correct method of raising a base-mounted TV antenna.
Since a base mount must be guyed, an easy way to
raise the mast is to first fasten one of the guy wire
screw eyes to the roof peak on the end of the roof
T
M
OOLS,
ASTS &
Fig. 4-11. Pitch Pad seals should be installed under the tripod legs.
opposite the direction in which the antenna is lying.
Run the end of the guy wire through the screw eye.
Have your assistant slowly raise the mast while you
pull the guy wire through the screw eye (Figure 4-10).
When the mast is vertical, the guy wire you are
holding will be approximately the right length for
permanent installation. Temporarily secure this guy
wire. Install the other guy wires while your helper
holds the mast in a vertical position. Check the mast
with a level as you tighten and permanently secure
each wire. When the mast is vertical and each guy
wire has been tightened, orient the antenna and
firmly tighten the U-bolt (clamp) on the base mount.
Tripods, as noted earlier, are a stronger, more rigid
type of roof mount. The most common tripod mounts
are 3, 5, and 10 feet high. The 3 foot tripod is most
commonly used.
A tripod mount can be installed and leveled before
the mast is inserted. It should always be mounted so
that the antenna can be folded down along the peak
of the roof. This will enable you to lower it more eas-
ily should repairs or adjustments become necessary
in the future. Even though tripods are very stable, any
tripod-mounted mast over 10 feet high should be
guyed.
Ensure the sturdiness of the tripod by anchoring. To
protect the roof, use a pitch pad seal under each
tripod leg (Figure 4-11). Coat all lag bolts with roofing
tar or other sealant to prevent leaks around them.
Roofing tar or silicone should be used liberally
around all holes, bolts, screws, nails, and eye screws.
HA
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EQUIREMENTS
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