Building Construction, Renovation, Maintenance & Advice

Polycarbonate roof sheeting

"Beauty is in the eye of the man who sells it"

Fashion, what a strange phenomenon. People, like mindless sheep, seem to lose the ability to think for themselves and blindly follow the herd wearing clothes or hairstyles they don't even like but – well we all have to follow the fashion don't we even if it does hurt our feet.

Mind you it isn't anywhere near as bad as it used to be. The social revolution of the '60s liberalised things a lot but back in the '50s clothing fashions were very regimented and everyone followed them. If you dressed in something “different” you were immediately branded as some sort of anarchist. It was a time when men never went out without a collar and tie. Changes were, by modern standards, very slight but everyone noticed. The width of the tie might change slightly or the shape of the collar. Winkle picker shoes evolved into chisel toes. Men all had short hair but great importance was placed on just how short or whether the back was round or square. Short back and sides and crewcuts came and went and sideboards were particularly daring.

Then the sixties came and the revolutionary move that really shocked the world – long hair. “God help us, the world as we know it will collapse”. Surprisingly to many the world didn't collapse and we survived. But then a whole series of very different fashion changes came in quick succession. Flared jeans, paisley shirts and ties (remember them?), flower power, mods, rockers, punks with their heads shaved and Goths looking like something the cat dug up. It became quite chaotic there for a while with people doing everything they could to try to be different, it became fashionable to not be fashionable - as long as you were fashionable about it. These days, thank goodness, people simply wear what they want. Nowadays you can walk down the street in a nappy and no one will turn a hair.

You might note that building design has followed similar trends. As a child I remember that houses were all identical. Built in rows the only difference was that they had either green paint or brown paint on their window frames and external doors. My father caused a real stir down our street when he mixed some old paint and our house ended up with a sort of blue green colour. The curtains fluttered for a long time but lightening didn't strike my father down, buildings didn't collapse and, as people started to realise the world might actually survive the onslaught on normality they started to copy it, blue green paint started to spring up everywhere. It was truly a revolution.

As in other areas of fashion building design went through a process of liberalisation and, we now find streetscapes that have lost their regimented look but, dear me, we have seen some rubbish along the way haven't we? At one time in Australia they went through a phase of building fashion that I can only describe as the “Toybox” period. It was a lazy, low cost style really. They would build a structure out of concrete columns and beams and fill in the gaps with bricks. Then, to try and “decorate” the boring utilitarian box they had created, strange steel fabrications of pipes and shapes such as triangles, squares and anything else that looked even vaguely shapish would be bolted to the outside and painted bright red, yellow, green or blue. The result was hideous rather like something out of Noddy and Bigears. The amazing thing was that no-one ever stood up and said “Come on you parrot faced, warty wazoks, you have the creative skills of a bank manager's dog.

“Toybox” was probably something different however. It was a “fashion” created by builders because it was cheap. Build a cheap box then bolt something on to fool people into thinking that there had actually been a design process involved somewhere.

Of course sales people will always spout out the old line, “it is a matter of supply and demand you know” and “fashion is governed by what the customer wants”. I think I smelled a rat in that argument when I was about 3 months old and I was given a nappy that didn't fit.

Fashion is, as we all know, decided by what some smartarse wants to sell us. In housing many “fashion” developments are driven by the “I'm a greedy sod” gene while others result from the finding of a supposed solution to “a common problem”. Britain for example is a busy place these days the streets bustling with silken tongued creeps who knock on doors and persuade unsuspecting innocents that they need to install damp proof courses in their chair legs, double glazing on their picture frames and roof insulation in the dog kennel (mind you after a night out with the lads in the depths of winter a warm doghouse might just come in handy).

These fake fashions are often blindly taken up by everyone until suddenly something “new” is found and suddenly everyone realises that the earlier solution was about as effective as a bog roll in a swimming pool.

One such “solution” currently in vogue is polycarbonate roofing which has been taken up wholesale across the island. All over Denpasar there are little yards with a frenzy of highly skilled former watch salesmen welding up steel frames on which to mount the magical plastic sheeting.

Oh sure it looks good but it does have a few problems.

Having wrestled with this material for a while now I have found that it always seems to leak. Fix a leak here and it leaks there, fix a leak there and it leaks over there. After a while you start to get a little confused. Twitches settle in around your mouth and you start to wonder if your dog is having an affair with the milkman. Friends start accidentally leaving psychiatrists name cards on your coffee table before rushing off to that urgent appointment to get their tongue pierced.

Then one day a strong wind comes along and elopes with your plastic roof and suddenly sanity returns, and, like a spotty faced teenager that has finally had his first bonk you wonder what all the fuss was about.

The polycarbonate material we are discussing, often called names such as solarduff, twilite or b$%&*y c£%@p (how did that British pound get in there?), looks like corrugated cardboard made from melted down cola bottles. It comes in a range of colours such as smokey grey, barf blue and spittle green and is usually installed by skilled pheasant pluckers who nail or screw it to a steel or wooden frame.

The trouble is the plastic is fairly thick with hollow flutes through it. It compresses as they tighten the screws up too tight leaving a depression in the plastic, water sits in the depression and finds its way, as is its wont, through the hole round the screw. To make matters worse the plastic may crack, especially after the sun has been on it for a month or two, and you will see water lying in the flutes of the polycarbonate sheet. You stand a much better chance if you (1) make the holes bigger to allow the plastic to move a little and (2) install a rubber seal under the head of the screw.

Success is still very elusive and the series of complaints that follows brings the return of our trusty tradesman who learned to install roofs while creeping around the ladies underwear department at Ramayana. They have in their hands the ubiquitous solution, the answer to all our property maintenance problems from leaking baths to dead cats in the water tank.....

SILICONE!

Just one slight problem that two million frustrated leak sealers have failed to notice, silicone doesn't stick to polycarbonate very well, in fact usually not at all. You do stand a better chance if you clean the plastic with a degreaser first and use acid free silicone but a better bet is to use something with a lot more sticktion such as Sikaflex.

Look at virtually any polycarbonate roof and you will find blobs of silicone daubed along the joints and blobbed over the screws heads. The dribblings of frustrated leak sealing attempts.

But just a minute, why would people produce this material if you can't install it.

The answer to that is quite simple but, until now, has only been known to the inner circle of a secret men's society that meet once a month in a bus shelter in Renon. Polycarbonate sheet roofing comes as a system. In addition to the plastic sheeting itself the system includes specially designed aluminium joining and edging channels and rubber sealing strips all designed to secure and seal the plastic sheeting without putting screws or nails through it.

When the full system is used and properly installed polycarbonate works very well and there are a couple of roofs around that have been correctly installed using the correct channels and rubber sealing strips. These are usually brought in from Surabaya and I am not aware of anywhere in Bali where the correct channels and seals are available. Of course your trusty tradesman will always assure you that the channels he supplies are the correct ones, that silicone is just as good as the seals and that the screws through the plastic are necessary to hold it down.….... You would be far better buying an umbrella.

There are alternatives to polycarbonate sheet, for a high quality look you can use strengthened glass. For lower cost applications such as carports you can use a plastic known as Chladian instead but don't forget: it needs to slope enough to drain properly, install it with a good overlap, drill bolt holes in the plastic slightly big to allow the plastic to expand and move, use rubber seals under coach bolts and DON'T TIGHTEN THE BOLTS UP TOO TIGHT.

A good friend of mine has recently torn down the disastrous polycarbonate roof on his carport and is installing a pretty swish looking shingle roof.

Copyright © Phil Wilson 2009
This article or any part of it cannot be copied or reproduced without permission from the copyright owner.

17 July 2017 Copyright © Mr Fixit,
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