What I am going to be talking about here is external fixing of roof sheeting. Not the secret fixed and crimped or the seamless sheeting.
I will be using the names as used in Australia, but other countries use the same technology with similar profiles. The photos show fastenings that are for cyclonic areas. They are typical for other regions, but the spacings could vary.
Corrugated roof sheeting or roofing iron has been around since the 1830's in England. It was and still is a significant invention. The simple process or forming corrugations into a flat floppy sheet of thin iron changed roofing for ever. Because of it's lightness and strength, easy transportability, tons of it was shipped all over the world, including Australia.
Types of Roof Sheeting Available.
Here, as far as I know the locally produced steel roof sheeting in Australia all comes from the one source, which used to be called BHP but now is using the name BlueScope. I will be using their names for the material and profiles, but local suppliers use their Types_of_Sheeting_Available.own names for what is the same base material and the same or very similar profiles.
The main product that has replaced the old galvanised iron is called "Zincalume". This name being derived from the two main components of the actual coating system, which consists of Zinc 55% / aluminium 43% / silicon 1.6% that coat the steel base.
The material is sent from the steel mill in large rolls of flat sheet. (I'd guess a couple of tonnes per coil). The main difference in the coil products are:-
Various local companies do the roll forming. They turn the coils of flat into various standard profiles for which the engineering properties are documented. There are quite a few roof sheeting profiles available, but the main ones for housing are as follows:-
You can see from this short list, that the shallower the roof sheeting pitch, the
deeper the ribs have to be, and also the thicker the material in most cases.
A visit to BlueScope's website will give you heaps of detail.
Before you get on a roof.
Read the roofing safety page
Get your ladders set up right. Here's a link to my ladder safety, handling ladders page.
Maintenance of Sheet steel roofs and walls
Modern Steel roofing if done well will last as long as the rest of the house! Easily, no sweat! The manufacturers say that under normal conditions where the roof is washed down with rainwater no maintenance needed.
Read what I said about maintenance on my roof care page.
I advise that you do a bit of preventive maintenance every so often. Note I am not specifying a time frame here. Only you can judge your own conditions.
The most common mistake that people make when trying to fix small leaks in their roofs is using the wrong sealants. Any silicone that says "acidic cure" is not compatible with Zincalume based roof sheeting. That includes most of the bathroom, glass and wet area stuff. You must use neutral cure silicone. It usually says Roof and Gutter etc.
There are a few other materials that are are incompatible with one another, and then there is the problem of galvanic corrosion. Do NOT miss this page if you work on steel roofing.back to top
Stripable Plastic Coating
Don't fix flashing with it still in place, thinking that it will peel off afterwards. It does come off, but it is a pain to do it, and there are always dags of plastic around the screw heads.
If you have left overs from a job and think you might find a use for them later, strip off the plastic, or they may be useless in a few months time. Certainly if left in the sun
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Please Note! The information on this site is offered as a guide only! When we are talking about areas where building regulations or safety regulations could exist,the information here could be wrong for your area. It could be out of date! Regulations breed faster than rabbits!
You must check your own local conditions.
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