Designer N is planning a new btah for a second floor bedroom. The floor was not designed to support the wight of the heavy cast iron bathtub she has specified for the rpoject. What would be the best and most cost effective method to add additional support for the bathtb?
A. Add two layers of 3/4\ plywood in the tub area B. Add extra floor joists in the tub area C. Place steel \I\ beams under the tub D. Replace the existing 2x10 s with 2x12 s