Sorry, I was not very clear. We have to mount floor timbers in a house using galvanised joist hangers as we need to lower the floor. The previous floor rested on top of the wall whereas we need to be 14 inches lower fixing the joist hangers to the rendered brick work lower down. The idea of being able to fire fixings in with a nail gun would save a load of time as the alternative is to drill, plug and screw some 400 times! Tedious.