If partially or totally concealed connection hardware is desired and a customer’s Heavy Timber Trusses are either (a) Structural and/or (b) oversized, our most common method of construction is to use “Hidden” or “Knife” plates.
This method involves cutting concealed slots or “plunge cuts” in the center of timbers, into which a single gusset plate is inserted out of view. The plunge cuts are generally made from the top sides of the truss members so they are not visible from below. Holes are drilled through the timbers to coincide with holes in the gusset plates. Bolts are installed with washers to bear on the wood.
The bolts may be installed with the bolt head, nut and washers exposed at the surface, counter-sunk flush with the surface, or counter-sunk below the timber surface, covered with a wooden plug and sanded smooth so the all hardware is completely hidden from view.
The counter-sunk and plugged approach may only be used if the timbers are of sufficient thickness to permit this configuration.
There are some truss geometries that will not allow hidden plate construction for engineering reasons. SWC will advise the customer when hidden plates are not permitted.
There is significant additional labor associated with the hidden plate fabrication approach so extra lead time must be allowed.