of the cavity being formed when the clamping device is tightened the respective horizontal portions 68 72 of the first and second wall engaging components are tightly secured to each other in this state the overall length l of the clip 60 is fixed and the clip is effective to retain the partially constructed wall in place as the foamable material is introduced into the cavity as best shown in fig1 the contacting faces of the horizontal portions 68 72 can be formed with teeth 82 or similar surface features that intermesh with each other and prevent slippage between the first and second wall engaging components as best shown in fig1 the clamping device 66 can include a fixed nut 84 that is fixedly secured e g welded to the lower end portion of the shaft 80 and a rotatable knob 86 received on the upper portion of the shaft 80 the knob can have internal threads that engage external threads of the shaft an o ring or washer 88 can be disposed on the shaft 80 between the knob 86 and the fixed nut 84 rotating the knob 86 in a first direction e g clockwise is effective to secure the wall engaging components to each other while rotating the knob 86 in the opposite direction e g counterclockwise is effective to loosen the clamping device and allow for adjustment of the clip 39 s length in view of the many possible embodiments to which the principles of the disclosed invention may be applied it should be recognized that the illustrated embodiments are only preferred examples of the invention and should not be taken as limiting the scope of the invention rather the scope of.