Embedment mechanisms at a glance

The first part of our guide for rear-ventilated facades described the design and the advantages of this special type of facade. The next section deals with the topic of fastening.

There are three different embedment mechanisms that form the basis for attaching a rear-ventilated facade: by frictional connection through expansion, guided connection through undercuts or adhesive bond through composite. The current part of our guide for rear-ventilated facades will illustrate how these three principles work and how they differ.

Frictional connection

Nylon anchors and through bolts generate their tensile capacity in the substrate through their frictional grip. When using a nylon anchor, this anchor is pressed onto the wall of the drilled hole by tightening the screw. The greater the pressure, the greater the friction and therefore the force required to pull out the nylon anchor again. With this form of embedment it must be observed that the high expansion pressure requires corresponding axle and edge distances to prevent substrate splitting or edge fracturing.
 

Guided connection

Undercut anchors for concrete or injection systems for perforated bricks generate comparably high tensile capacity due to the guided joint connection with the substrate. A key advantage is the low expansion pressure and the high safety on cracked substrates.
 

Adhesive bond

Anchor rods which are bonded with injection mortar into solid building material achieve their tensile capacity through an adhesive bond. This does not create expansion pressure, so low axle and edge distances can be used. A further advantage for application in unprotected outdoor areas is that the embedment is protected from moisture penetrating it, and thereby also protects the reinforcement rods from corrosion.

The next part of our guide for rear-ventilated facades will look at single vs. multiple fastening of non-load-bearing systems.