How do you calculate the grip length of a plastic facade anchor?
Based on the details of the total length and the details about the installation depth of the anchor in the substrate, the so-called grip length can be easily calculated. For example, the red anchor, SDF-8V, has an installation depth in the substrate of 50 mm. These details are listed in the ETA of an anchor. If the anchor has a total length of 80 mm, an attachment with a maximum thickness of 30 mm can be fastened.
What is the difference between push-through and pre-positioned installation?
All fastenings are designed as push-through installations as per EAD 330284-00-0604. For this purpose, the anchor sleeve is inserted through the pre-punched attachment, for example, the rainscreen facade wall bracket, and the screw is then tightened until it comes into contact with the anchor sleeve. The clearance hole diameter of the attachment is listed in the key assembly values of the corresponding ETA. Push-through installation is characterised, in particular, by the anchor sleeve and the associated screw being precisely reconciled to each other.
This reconciling, together with the defined installation situation, guarantees a reproducible expansion behaviour of the anchor. In addition, during the push-through installation, you can actually see whether the sleeve in the substrate is also turning while tightening the anchor screw. With so-called pre-installation, which is popular on the construction market, this is not possible. In the construction segment, anchor sleeves and screws are sold individually, and it is down to the customer which combination of sleeve and screw they use for a unit, which leads to a non-reproducible installation situation.
