About 7 months ago we had a new extension built and had a wall knocked out and an rsj installed. I recently had to lift the floorboards above the rsj as they were squeaking and noticed that the joist hangers have been nailed in and have had their tops cut off. The joists are supporting a brick wall, I am no expert at all but I expected the top of the hanger to wrap onto the top of the rsj and surprised it was only nailed in. Does this contravene building regs?