Steel | Corrugated Roof Waterproofing.


AKA - Galvanised Sheeting

The Steel Roof(galvanised roof system) : General Information and Guidelines

Definition of steel sheet Vs Galvanised Sheet is: In the manufacturing industry (including both metal stamping, and metal spinning) galvanized commonly refers to galvanized steel. Galvanized steel is regular steel sheets that have been coated in zinc to make them corrosion resistant.  Regular steel is made of iron which will rust when exposed to moisture, either in the form of rain or ambient humidity. Over time rust will corrode a steel part to the point of failure.


What we offer at Fix A Roof when dealing with roofing issues and that being the leaking or intended purpose of the roof we always keep one thing in mind, be thorough and make sure all the basics are in place, structurally and build quality.

Leak Assessment & Importance of it - In so many cases when the roof was new, there were no leaks/issues. So that is true but taking into account should the roof in the first place be teetering on the border of what a low pitch galvanized sheet roof with a cheap knock-in screw/nail system with plastic washers can realistically take and still be waterproof this is another thing. Structures settle and sag, wood and steel aside. We are trained to firstly see what is a structural issue causing the leak or if its just time for a service.

Why Galvanised roofs start to leak | Thermal expansion - occurs when the heat is added to most materials, causing the material to expand. Consequently removing the heat energy (cooling) causes the material to contract. Each different material type expands at a set rate peculiar to that material for one degree in material temperature change. This rate is known as the thermal expansion coefficient for that material (see table 1).

Roof Fastener Combos & How Technically Advanced They Really Are -  

Using a proper fastener system with the appropriate washer is simply down to the right tool for the right job. The design of the screws for instance have sections where they have both a reverse thread(top screw section sheet nip) and convention thread to tighten the sheet to the substrate\truss\batten and this to stop dimpling at the point the screw and washer pull the sheet down causes pooling which is a direct rout to a leak threat. Rubber boned washers as a unit example are far better equipped to thermal cycle issue by a purpose build rubber compound that caters to this from the get go.A roof sheet in summer experiences massive thermal expansion which is a wear factor, now add in a quick rain shower (immediate contraction through cooling) and it quickly becomes apparent why if an incorrectly specified fastener system is used it will never perform long term as the intended purpose of the fastener system has to match the technical requirements of the real world application it must perform. 


Thermal Expansion Table Guideline - Zinc