Slab at garage door. How to insulate? Hold back PEX?
2 questions. Zone 8. My ICF foundation wall will have 8″ of rigid foam on the outside, and my slab will be floating inside the ICFs. That has to change a bit when I get to the garage door opening. If I stop all the outside foam, including that of the ICF, 4″ short and pour a concrete approach apron, smack against the concrete in the ICF, I could drive right over the top of the ICF, inner foam and all, right to the slab. The inner ICF foam will eventually compress, look gross, and fill w/ debris, but at least most of the slab edge would be somewhat insulated. Q1: Does anyone have any details for insulating there, or should I just bite the bullet, run the slab over the ICFs, and accept the thermal bridging? (2) Too, should the PEX in the slab be held back an extra 18″ to reduce the chance of it freezing? I don’t think the boiler will be circulating water through the floor all that often, so I am concerned about water sitting too long at the garage doors. Water temps, via Siegenthaler’s “Mod Hyd Heat” book (if I did the calcs right) show a water temp of about 82 F. Other calcs show 1.6 btu/hr/sf heat loss, about 6 btu/hr/sf at design temp. Thanks for any suggestions. john. Oh, yah. The Ferrari is 4×4, w/ studded tires and a trailer hitch (to pull my skid steer).
GBA Detail Library
A collection of one thousand construction details organized by climate and house part