Any fixings which are to be used to attach steel roofing to purlins must be able to withstand wind pressures and varying weather conditions. The specific fixing required is dependent on what roofing profile you are using, the purlin type (light steel, heavy steel or timber). We recommend the use of self-drilling TEK screws which are created with 5/16th hex head for superior performance.
The screws we provide have a specific drill point to drill through the steel sheeting and purlin before then tapping into the purlin itself. Beneath the head there is a stainless steel washer which is 19mm fitted with a neoprene bonded pad that will compress to ensure a seal to the roof sheet.
Depending on the sheeting which you are installing, the screws can be installed into the sheetings crest profile or use a longer screw and baz washer when installing corrugated sheeting. All screws provided are self drilling TEK screws, however if you prefer you can centre punch an indent into the metal sheet at the point you wish to install, this can help to ensure the screw stays straight when drilling.
Remember – do not overtighten or under tighten your screws as this can affect the performance of the washer and prevent it from sealing correctly. See diagram below.
How to install Cladco Steel Sheeting
Steel sheeting can be installed simply and easily using cladco screws and accessories, the type required will be dependent on the profile and purlin material used in the project. 5/16th hex head self drilling TEK screws with a neoprene washer and stainless steel head can be used in the lower portion of the steel sheeting profile to fix the sheeting to metal or wood purlins.
Longer screws are available in lengths up to 175mm which can be used when you need to install through thicker material such as insulation.
Cladco Box Profile 34/1000 sheeting has 6 troughs,
Colour caps are available in a range of colours to match the steel sheeting, these caps can then be used to cover the screw heads.
Installing the sheets is simple to do using Cladco screws, for installing box profile 34/1000 the recommended installation is through troughs 1, 3, 4 and 6. The lower end of the sheet can be fixed through every trough to ensure the wind does not uplift the steel sheeting.
When installing tile form sheeting the screws which are required depend on the purlin composition. To install tile form sheeting we recommend installing into trough 1, 3 and 5. As above the lower end of the sheet can be installed through every trough to prevent wind uplift. When installing through thicker material or insulation you can use longer screws of up to 175mm length. As above, colour caps can be installed on the screw hex head to cover the stainless steel material and match into the steel sheeting coating colour.
To install corrugated steel roofing sheets the purlin material must be considered. Cladco supply fixings for most purlin compositions and thickness. Corrugated roofing sheets should be installed into the corrugated sheets crown using a 65mm TEK screw with baz washer. The general advice for fixing is 4-5 screws across the sheets purlin, we advise using 1 screw on the overlap of the next sheet. As with all of the fixing screws provided, you can use a colour cap to hide the stainless steel head.
When installing a helpful tip is to use a stretched string piece lined up along the purlin line, this can ensure you keep the fixings in line with the purlin.
You will find all fixings and accessories you need in the accessories section of the website as well as metal Z purlins.
For further advise on installing your steel roofing sheets, please see the help and advice section of the website. Should you require further assistance please contact us where our friendly sales team will be glad to assist you.