Rogues Gallery

We came across this in a windy east coast town. The building is a block of council flats, and this is the aerial for the communal TV system. One of the entrances, used all day and every day, is directly below the aerial, next to the red fallpipe. When we arrived people were going in and out with never an upward glance.
The aerial at the top of the mast is a Televés DAT75, a very heavy item that catches the wind. Lower down is a cheap 10 element UHF aerial and below that a two element VHF-FM aerial. The mast is 16 feet long, with 10 feet above the uppermost of the two wall brackets. The brackets are about two feet apart.
Where do I start? I suppose the worst thing is that which gave way first – the plastic plugs and coach bolts, which are quite inadequate for such a load. The large-scale use of plastic plugs by the aerial trade came about because Sky installers are supplied with them. If used properly they are perfectly adequate for a little satellite dish, but of course if Mr Cowboy Rigger has them in his van he will use them for everything. They are so irresistibly quick and easy and cheap.

In this case it was inevitable that the plugs would pull out of the wall, and I think the installer knew in his heart that he was pushing his luck. That’s why he didn’t push the mast up as high as possible. He left a good four feet of mast hanging below the lower bracket. Incidentally the surplus mast length should have been cut off, for the sake of neatness.

Personally I don’t use plastic plugs for anything, even dishes, but if you must use them please bear in mind that they have their limits. There are all sorts of really good fixings on the market. I generally use sleeve anchors for fixing to brickwork. The pullout force these will withstand is limited only by the strength of the wall itself.
The bracket pair used here is known colloquially as a ‘T and K’. Why I don’t know, because the lower one doesn’t look remotely like a ‘K’, but in any case they are not strong enough for this loading and they don’t have enough fixing holes. What’s need is a pair of ‘tripod’ brackets. These are inherently stronger than the ‘T and K’ because of their shape, and they have a total of eight or twelve fixing holes. The ‘T and K’, especially when it has a large stand-off, can break at the welded junction if overloaded. The ‘T and K’ is fine for reasonable loads, but not for something like this.

If the installer had made use of the full mast length and positioned the lower bracket four feet further down the wall, the strain on the brackets and fixings would have been much less.

Note also the coil of surplus cable taped to the lower bracket, and the old brackets left on the wall to rust.
What a pity it is that local councils use such cowboy contractors. Surely a bit of quality control would be in order. Or don’t they care about wasting the public’s money? Could it be that everything else in this building, the plumbing and the electrics and so forth is done to the same abysmal standard?

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