Installations that require mechanical attachments:
Wall caps that are in a public area known for skateboarders should have a mechanical attachment and skateboard deflectors. There are a couple of methods to attach wall caps.
One is using threaded inserts cast into the precast concrete. The installer would then need to purchase threaded dowel rods, drill holes in the masonry in the exact location, (not as hard as it seems, but time-consuming), and then by using the appropriate setting materials (a select choice of mortar) install the wall cap.
The following method is less costly for material and labor. Casting brick ties in the wall caps, the installer can slide the free end of the brick tie underneath the last unit set and pin the other end to the masonry wall. This method uses less labor and therefore less installation cost. (See drawing on attachments of wall caps).
Arch trims with or without intrados should always be mechanically fastened as most areas with arches will have foot traffic. There are several methods to fasten these materials. The weight of the precast will dictate the strength needed for the attachments. Brick ties, clips, and pin, or threaded inserts can be used for these attachments. (See attached drawings).
There are many ways to mechanically attach architectural precast concrete. Larger products may require a different attachment method than smaller products. You can easily over-engineer attachments, therefore adding cost to your project.
Problematic mechanical attachments:
Protruding attachments cast into precast concrete creates packaging and shipping issues. The precast parts are more difficult to package. Certain attachments limit the number of parts that can be packaged on one pallet, therefore creating the need for additional pallets and possibly add to shipping costs. (Value engineering is out the window).
Casting embeds into the precast:
Many shapes and applications of precast will require embeds for mechanical attachments. Stair treads often require embeds to attach to steel runners. Some designs require imbeds to protrude outside of the rear side of the precast. Though this application cannot be eliminated from the design, it usually will create an additional cost for packaging.
Please keep this in mind during your design. Many times, threaded inserts can effectively do the same thing. Engineering may be required for certain applications.
We will show you a few dos and don’ts for embeds.