When it comes to fitting a digital TV aerial in a loft, there are a couple of things that need to be considered. Firstly, the Aerial fitter would need to ascertain how many TV points are going to be coming off the aerial. Also, the engineer would need to find out if there are going to be any obvious obstructions to receiving a quality signal. There is already the loft and roof itself that can reduce the signal strength received in the loft by up to 50%, and in some lofts with certain types of insulation on the walls and roof space there is no way of receiving a TV signal at all.
The only way of really finding out is to rig up an Aerial to a spectrum analyzer and trying to pick up the best signal whilst in the loft. Depending on the signal strength and also quality the aerial & satellite engineer can decide not only if an aerial can be fitted in the loft, but also if there needs to be an amplifier installed to boost the signal. If an amplifier is needed, then the type of amp or booster sometimes depends on whether there is a power point in the loft. If not then the use of a masthead amplifier is the best option.
The benefits of a TV Aerial Installation in the loft is that usually all the cabling and the digital aerial itself is kept dry and away from the ravages of the UK weather. This drastically reduces the chances of corrosion and improves the lifetime of the whole aerial system. Once a quality digital TV aerial is installed by a TV Aerial Installer and everything is tested and running well, then the system should not need to be looked at again for going on 10 to 20 years.