Tuesday, September 13, 2011

new use for old television antenna towers

We have a large west facing deck which can become unbearably hot on a summer afternoon. I used old tv antenna towers to create horizontal struts on which to hang landscape fabric making a very effective sunscreen that did not catch the wind.

I wanted to create a sun screen to partially shade the deck. The deck is 20 feet wide so the span would have required a fairly massive structure if made from wood. I looked at metal trusses of the kind used on portable stages and exhibits but was discouraged by the high cost.

Since the advent of cable and satellite TV, many homes have antenna towers that are no longer being used. Former antenna installers now have another business of tower removal. Many of these surplus towers end up as scrap which is a shame since they are potentially very useful strong structural trusses as used here as a support for shade cloth over our deck.

I got my tower sections from the yellow pages by calling a local antenna installer. They were cheap, about $100 for the four ten foot sections. I specified that they all had to be the same or at least identical pairs (so that they could be fastened together and for appearance purposes). I didn't want the top section, the one that narrows down to hold the antenna mast. I bolted the sections together into two 20 foot spans, sanded and painted them with primer and two finish coats of white rust paint.

I created the vertical support posts from 4x4 inch pressure treated wood, spliced to the existing porch supports. I arranged an overlap of the existing and new posts of about four feet and fastened them together with nuts and bolts in three places. This was a convenient mounting method as it meant that I did not have to dig new post holes under the deck to anchor the awning support posts.

At the tops of the support posts I made up yokes out of pressure treated 2x4 inch wood with arms to support the antenna towers at their ends. Metal straps across the openings in the tops of the yokes anchor the towers to the yokes. I spent about $75 on wood and hardware.

For the awning, I first tried brightly colored nylon cloth. Although light in weight and pleasantly colorful, the cloth panels acted like a sail in strong wind and the buffeting noise and the thrashing they took was alarming. I took the nylon panels down.

One day while visiting a garden center, I noticed the shade cloth that was suspended above the plants. This seemed like an ideal material and the open weave I thought would not catch the wind so well.

After looking around locally for sources of supply without success, I ordered shade cloth from greenhousemegastore. I got the 60% black. My order arrived quickly and was well made. Cost was about $100.

They have standard or custom sizes with eyelets installed in a reinforced band around the edge. I put the shade cloth awning up with long tie wraps and bungee cords.

We are very pleased with the result. The old televison towers are incredibly strong. I can do a chin up in the center of the span and they don't sag. The shade cloth provides welcome relief in the hot sun and isn't bothered by the wind. I take the shade cloth down in the fall and put it back up in the spring.

So I have saved four old tv tower sections from the landfill and for very little effort and a cost of about $275 I given them something useful to do.

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