The collapse of concrete formwork used to support concrete slabs, decks and roofs is a never ending problem. Each year hundreds of men are seriously injured or killed and many hundred thousands of dollars are lost in material and equipment. The causes of these failures are many, but there are three general categories into which formwork collapses and shoring failures can be classified: (1) faulty workmanship in the field; (2) external forces that overload the formwork before, during, or after the concrete is placed; (3) inadequate or faulty structural design of the formwork to support the expected design loads. Some of the more common critical areas associated with shoring failures are: (1) tubular steel scaffolding used for shoring. Under this heading would go such common problems as the height of screw jacks at base or top of scaffolding legs extending beyond their load carrying capacity and the unequal spacing of stringers in the top U bracket, causing eccentric vertical loading on the hollow leg members. (2) For wood and steel shores, common problems include the failure to scab spliced shores on 4 sides with adequate nails, square ends and maintain full contact between the two pieces spliced, the height of screw jacks on shores extended too far, and the size and bearing of sills on grade inadequate to hold shores or sills not properly blocked and leveled. The function of X bracing is to resist any unexpected external lateral forces on the formwork and shoring system which could cause a collapse. Some of the external lateral forces which have caused collapses in the past are: pneumatic pressure loads during placing operations against the bulkhead or deck; severe wind forces against the deck surfaces; any sloped or arched formwork surfaces for sloped floors and ceiling or arched slabwork which create horizontal or lateral forces when concrete is placed; and sliding or moving heavy concentrated loads of equipment or material on the deck forms which create lateral forces on the shoring system. Details of the X bracing layout should be clearly indicated on formwork drawings by a qualified engineer. Or, standards should be published on X bracing for varied layouts of common shoring systems which vary in shore height or spacing, only, for horizontal formwork.