I have a 40x60 pole barn that I am doing a slab in this summer. I plan on doing a radiant setup. I received a quote for 6 300' loops of 7/8" pex spaced at 16". That seems odd to me, I was under the impression that 1/2" pex spaced 12" would be the norm (2400ft of tubing in a 2400sp ft slab). Less...