Strongback Bridging (SB) is used as a load sharing element between the joists. When installed correctly, standing on one joist effectively spreads the load over 3 joists. As it is structural, it has to be graded timber, usually the same as what the SpaceJoist has been made from. It has to be installed in its vertical orientation, to a timber vertical either within the joist (chase vertical) or face fixed to the side of the joist. Minimum size is 35mm x 97mm TR26 but larger sections should be used on deeper joists. Using lower grade timber will have a lesser effect.