The Castlewood hidden fastener system features two clips, one locks and secures the board down (TC1 – Locking Fastener) and the other allows for expansion and contraction (TC2 – Control Expansion & Contraction (CEC) Fastener), so that you don’t experience warping or distortion of any kind after installation. The system works because it allows the user to control the direction in which the expansion and contraction will take place.

In simple terms the locking fasteners should always be used in the middle or near the middle of the boards. The TC5 Start/End Fasteners should be used at the first and last rows only.

If the preference is for a tighter gap between the boards than possible using the TC1 and TC2 fasteners, then the Metal Fasteners can be used.