A guide to tooling for sheeting and cladding
- Read time: 8 minutes
- Date: 24 Mar 2022
- Sheeting & Cladding
Using the wrong tooling or the right tools incorrectly means you may under- or over-drive the self-drilling fasteners you are installing in sheeting and cladding applications.
This not only looks unsightly, but it can also compromise the waterproofing (leading to leaks), reduce thermal performance and result in cracked or scratched panels. It can also damage the fasteners leading to a reduction in performance, which can impact the safety of the building.
So, it is essential to use the right tools and use them correctly. The good news is it will help speed up the installation process too.
What type of gun should be used to install self-drilling fasteners?
Cordless screwguns or screwdrivers can be used with self-drilling fasteners but must have the correct speed limiter.
If you use a screwgun that is too fast, the fastener will burn-out and blunt the drill point. Not only does this stop the fastener from driving, it can also harden the steel, so a new fastener won’t drill through the steel either!
Always refer to the manufacturer’s guidelines on the product datasheet regarding the maximum gun speed and check this against the speed of the screwgun you are using. However, as a guide, the maximum gun speed for installing self-drilling fasteners into steel is as follows:
Gun speed is not a concern when drilling into timber.
Can drywall or impact guns be used to install self-drilling fasteners?
Never use drywall guns or impact guns to install self-drilling fasteners in sheeting and cladding applications. Drywall guns have a rotation speed of up to 4,000 rpm, which is well over the 2,000 rpm limit for self-drilling fasteners, so should not be used.
The repetitive impact action of impact guns can lead to drilling failures, reducing the fastener’s pull-out performance. It can also damage the fastener’s coating or strip the moulded head. As a result, using an impact gun can invalidate the manufacturer’s warranty.
Is using a depth setting sleeve necessary?
Yes. A depth setting sleeve (nose cone or depth stop) ensures every fastener is installed to exactly the right depth. If you don’t use one, then you may install the fastener incorrectly.
The depth setting sleeve works by disengaging the clutch, automatically stopping the screwgun from driving the fastener further when the correct depth is reached. It also speeds up installation.
Follow these tips to use a depth setting sleeve correctly:
Choose a depth setting sleeve with a larger diameter than the fastener head. If the one that comes with your drill is too small, purchase an aftermarket one with the correct diameter for the fastener.
Set the depth setting sleeve to the correct depth at the start of each project. The best way to do this is to estimate the cone setting, then drill several fasteners, each time increasing or decreasing the setting slightly until you have achieved the correct depth.
This will allow you to remove and reattach the depth setting sleeve if required without going through the process of setting it to the correct depth again. Check the setting dial regularly to ensure it is still set correctly.
How do you stop the clutch from disengaging too soon when using a depth setting sleeve?
The clutch will only disengage early if the fastener has been driven in at the wrong angle because one side of the depth setting sleeve will hit the panel before the other. If this happens, it means part of the fastener is underdriven and the washer will be compressed unevenly, compromising the weatherproofing. Best practice dictates that fasteners should never be more than five degrees out of line.
This usually happens because the installer is holding the screwgun incorrectly. Most people automatically hold the gun in a pistol grip, but this distributes the weight unevenly and means the fastener is more likely to be driven at an angle.
How should you hold a screwgun correctly?
The correct way to hold a screwgun when installing self-drilling fasteners is with:
Your arm completely straight
The lip at the top of the gun sitting along your thumb and forefinger
Your little and ring fingers operating the trigger
This ensures the weight is transferred in a straight line through the screwgun to the drill point of the fastener.
Holding the gun like this rather than in a traditional pistol grip will ensure that the fastener is driven into the panel at a right angle. It also prevents skating (where the drillpoint of the fastener moves across the surface rather than penetrating it) which leads to unsightly scratches, especially on coated panels.
How do you choose the right drive bits?
Always use the recommended drive bit for the fastener you are using. This will support the head helping to keep the fastener straight and prevent skating. Match the length of the drive bit to the depth setting sleeve and ensure it is deep enough so that the drive bit sits against the flange of the fastener.
Check your drive bits regularly and if they are worn, replace them. If you are using magnetic drive bits, check that no swarf has become trapped within the head as this can damage the fastener and stop it from gripping correctly. Unfortunately, it is very difficult to remove swarf from magnetic drive bits.
Do you need to sweep away swarf?
Yes, always remove swarf to ensure it does not become trapped under the washer, where it can rust and compromise the seal. To do this, screw the fastener to approximately three quarters of its total depth and sweep or blow the swarf away. If the depth setting sleeve does not have a cut-away section, don’t wait until the cone is touching the panel because it won’t be able to fall clear of the cone and is more likely to become trapped.
Using the right tooling will not only help you to achieve the best possible finish by ensuring you have driven the fasteners to the correct depth and the right angle, but it will be much quicker too.
