Replies

1. 
   Malcolm_Taylor | Dec 10, 2022 06:53pm | #1

   buildzilla,

   Hopefully someone will come along with a good guide to link to. GBA has a lot of articles on them that add up to pretty comprehensive advice. I'll just add a couple of general observations.

   - Structurally, there isn't much that's unique to double walls. Loads aren't shared between the walls. You pick one and build it as you would any other stick framed wall. The other can be built without lintels, or (often) limits on stud spacing.

   There are dozens of variations to choose from, each with it's disadvantages and benefits. The two main approaches are:

   - Frame the house as you would a conventional one, then add a non-load bearing wall on the interior. This is probably the best approach for builders who aren't familiar with double wall construction.
   - Frame the house conventionally, and add a non-load bearing wall on the exterior. The main advantages to this method is you can make the walls continuous over the floor system, limiting thermal bridging.

1. 
   buildzilla | Dec 10, 2022 08:10pm | #2

   thanks malcolm,

   that's an easy way to think about it.

   so, assuming a target assembly consisting of double 2x4 walls,
   are there ever any situations where one 2x4 (exterior) wall would not be considered sufficient?

   examples:

   - a walk-out basement wall with two-stories above it
   - a two-story wall in a "great room"
   - locations that experience conditions of high wind

1. 
   Malcolm_Taylor | Dec 11, 2022 11:14am | #3

   buildzilla,

   Yes, the same restrictions on their use apply as if it were a conventionally framed house, both for loading of more than one floor, and height limits for tall walls. Those will vary depending on which building code you are under. If the prescriptive limits are too restrictive, you can either make the load-bearing wall from 2"x6", or see what a structural engineer can come up with.