Replies

1. 
   Steve Knapp CZ 3A Georgia|Feb 20, 2020 11:48am|#1

   I'll give your post a bump (and ask a couple of questions).

   Can you provide your climate zone? (See//m.etiketa4.com/article/climate-zone-map-including-canada).

   Is cost a factor? (Reclaimed rigid foam would be less expensive than rock wool.)

   Are you planning to tape the plywood sheathing?

2. GBA Editor
   Brian Pontolilo|Feb 20, 2020 12:30pm|#2

   Hi tricks73.

   For the most part I don't see any big concerns with your assembly. As Steve mentioned above, it's important to air seal, so consider taping the sheathing seams and using caulks and sealants as necessary to air seal where tape won't work.

   Also, is the WRB over the mineral wool intended to be your water control layer, or just a UV-resistant layer to hide the insulation from being seen through the gaps in the siding? In either case, you'll need to have a dedicated WRB to integrate with your windows, doors, and other penetrations, so it's important to plan that now. I assume that the felt paper will need replacement by the time you have siding and existing insulation removed.

   I don't have any experience or feedback on the two WRBs you are considering, but another option is Benjamin Obdyke's Invisiwrap, which is also intended for this purpose. BO makes high-quality products, so you may price out this as another option. And the open-cladding systems that I have seen don't seem to have much in the way of pest control. I'm sure that's because it is too obtrusive to the aesthetic, but I do wonder if a black mesh like BO's Cedar Breather would disappear behind in the gaps. Not sure...

3. 
   tricks73|Feb 20, 2020 05:10pm|#3

   Many thanks for your responses and suggestions.
   In response to Steve's questions:
   ——对不起,不是提供气候区,这是6
   - Budget is definitely a consideration, but I'm trying to avoid foam products where possible for a combination of reasons - thermal drift (XPS, polyiso), performance at low temperatures (polyiso), blowing agents (XPS), flammability / poisonous fumes when burning (all), chewability by critters (EPS)
   In response to Brian's questions:
   - Excellent points on the tar paper degradation and need for a dedicated WRB - since you both suggest taping the seams of the sheathing it sounds like we should remove the tar paper and use the WRB for dual-purpose - will look at the BO products and work on the window/door details

   Many thanks again

4. 
   Steve Knapp CZ 3A Georgia|Feb 20, 2020 05:38pm|#4

   Richard,

   I mentioned reclaimed foam since it is widely available and costs a lot less than new insulation (foam or rock wool). Using reclaimed material actually is a fairly green strategy, but I understand your reservation about this material.

5. 
   Tinaraes|Apr 10, 2021 01:42pm|#5

   Tricks73,
   We have a very similar project we are working on now with our existing rambler. Wondering what you ended up with and how it's working. Particularly wondering what kind of UV barrier you used. We are doing 3/4" open joint pine siding painted with pine tar over painted wood furring strips and rigid polyiso. Also, keeping our WRB at the sheathing behind the insulation so the black membrane is mainly for looks and bulk water.
   Thanks!
   Tina