Concrete porch deck pour against framing
Does this approach sound like my best option? I have a new house build and I have read extensively about this subject – especially the questions on this site. By mistake, the frost wall for the front (covered) porch is the same height as the foundation wall. This means that the 5 inch concrete deck pour will abut the sheathing. Framing is complete – no cladding yet. Because we have floor trusses, the zip board sheathing is the rim joist – ie: it goes down to the foundation sill plate. (see fig 1 and 2) . My mentor suggests that I cut and remove approximately 8 to 9 inches of the bottom of the zip board and replace it with a 7/16″ exterior rated concrete board (wonderboard or equivalent). Then, the concrete board gets the seams mended and then the whole concrete board is coated with a liquid flashing (Prosoco). He says for extra insurance, I could also cover the area with Henry Blue Skin or equivalent. I was planning on putting on stone veneer for some of the cladding and LP Smartside for the rest. Since I will be using Dupont Rainscreen (.25 inch) – Should I tuck this behind the concrete deck before the pour for yet more buffer? Or should I terminate the rainscreent above the concrete deck and let it weep onto the concrete? Note: I replaced all of the overdig backfill with compacted crushed limestone – down to the footings – 9 ft. deep in many places. No dirt is next to the foundation anywhere. So any moisture weeping from the rainscreen will dump into this extensive limestone backfill that is well drained. Thanks for your comments and assistance!
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