Input on a New Design-Build
Hi all! Need help pls! We are doing our first custom build here in hot and humid Houston (zone 2) with the priority of durability, good moisture management (no mold problems), and good indoor air quality due to family member(s) having environmental health issues such as mold sensitivities. It is a 2300sf 1-story full brick house with slab-on-grade foundation. Overhang is at 16 inches. We are aiming for an all-electric home and switching to induction cooktops, heat pump clothes dryer, and ERV system in lieu of the standard HVAC system to help make this home more efficient. Also going for a conditioned attic space. After researching quite a bit I still can’t fit the puzzle pieces together. Unfortunately, we had already signed up with a draftman (and paid him) when we found architects that would have been a better fit for us. Since we didn’t want to start over with the design we just need some guidance in some decisions while still keeping budget in mind. 1) We think this wall setup would be ok – 2×6 studs with zip r3, plus xps rigid insulation and spray foam cavity insulation. Would the zip r3 be enough WRB or do we need something else on top of that for efficient water shedding? Would Polyiso be better since it has the shiny top layer that reflect heat? any other suggestions on efficient setup for said climate? Zip seems to be a good product but what is making us hesitant is its potential to not deliver its intended functions because of poor installation by contractor (tape not put on right, creases that allows pooling of moisture, tape might not being able to handle the shifting of the house later on, tape needs to be applied in clean and dry surface which not all contractors would take the time to ensure and follow through on. Also, I’ve heard of doing weep holes on top and bottom of brick wall, not just the bottom; is this good advice? 2) Do we need a subfloor installed above the concrete slab on grade foundation before installing flooring of choice? We are thinking of LVP but have heard mixed reviews about it not being a good idea because it traps any moisture coming up from the slab and being a good idea because of its waterproof qualities? Is there anything besides Dorkin Delta-FL that we can install before putting flooring on that will provide a vapor barrier and capillary break from moisture coming from the slab and not jack up costs as much as the Delta -FL? 3) In the bathrooms, we’re trying to see if there are better products to use besides the traditional tile and grout because grout has its cons. Chanced upon a laminate bath and kitchen wall product called FIBO wall which is supposed to be better than using tile and grout. Please share your opinion on which direction we should go. 4) How do we address the roof setup for our needs as described earlier? Use the brown Zip sheathing, put an ice and water shield on top of that before installing the composite shingles? 5) With building science application in mind, which would be our: a) water barrier – Zip R sheathing b) air barrier – Zip R sheathing? c) vapor barrier – ?? d) thermal barrier – External rigid foam insulation and spray foam cavity insulation besides the one I mentioned? I might have missed something. If this was your build, how would you set this house up given the details I shared? What other things would you add or take out to make this a great build?
Anybody used Aerobarrier with great success?
Thanks so much!
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