Exterior insulation thickness with SilvrBoard
We are currently just finishing up our ICF basement of our new cabin build. We live in Northern Saskatchewan so we are the high climate code. The basement is going to have an insulated slab (above due to some miscommunication – is 2 inch EPS for R value of 10 enough? Then two layers of 1/2 inch osb tongue and groove screwed together) and R30 ICF with 8 inch core. It is walkout on one side to lakefront.
We are currently getting ready to do the floor system and then begin the walls. Walls are 2×6 with R24 bat going in. I had originally planned on doing 2 inch SilvrBoard but my builder recommended against it due to using heavy Hardie Plank requiring strapping to install it. He suggested just a half inch of the same product to give a thermal barrier. I know the calculators have a much higher thickness but this was all with previous products that did not allow the water to exit – SilvrBoard is supposed to allow this.
Side note: do you suggest making the OSB sheathing the airtight layer? Interior vapour barrier still if you do that? Do most now apply a caulk/glue product to all plates and what not when installing exterior walls to make better seal?
With exterior rigid insulation – can rock veneer be applied? Does it require a rain screed or drip layer?
Thanks in advance! Fantastic information on this site.
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