Antennas inside roof space – do they work?
The age old question that I get asked is – can my antenna be mounted inside the roof space?
Sure, anything can be done, but how good will it work?
While this type of installation is advised against, many customers still find this placement attractive. While signal is greatly decreased when mounting a TV
antenna inside the attic, with a few careful steps this can be done successfully in some cases.
The answer whether in-roof antennas work is not simply a yes or a no, however a varying degree of reception reliability from perfect, intermittent to failure to display
or scan in any channels. This is all dictated by the available Signal Strength and quality outside and inside your roof
The first fundamental that must be understood is the signal that is available outside your roof, before it is degraded after it penetrates through your roof.
In Perth for example, areas where signal is very strong are Dianella, Morley, Ascot, Midvale, Cannington and Ballajura for example. The signal strength and quality
in suburbs like this is known amongst installers to be very strong and is able to make it through obstructions such as roof tiles and still maintain an acceptable level
inside the roof space where the antenna will be placed.
In comparison, trouble areas such as Fremantle, Scarborough, Wembley Downs and Claremont have a very low signal strength available at lower heights, which generally
after penetration through roof structure will not provide an adequate signal strength and quality to the antenna inside the roof.
Once the fundamental of available signal strength is understood, we consider the variables that will effect that signal
– Roof Surface – Generally a Tile roof will pass the signal without too much degradation. Any sort of sarking or insulation under the tiles will heavily degrade the signal strength.
A metal roof will block almost all the incoming signal. It is only in rare cases where signal strength is very strong that reception is possible, however
– Antenna position – With in-roof antennas, height is a major factor, even small adjustments in height can yield noticeable improvements. Adjustment is also important so it must be ensured
the antenna can point toward the correct direction of the tower in the proposed installation area.
The conclusive rule of thumb is – An in-roof antenna installation is possible in any suburb that has a very strong signal of 70dbuv and higher available and where the antenna is being installed on a house with a tile roof without any sarking or insulation.