framing doors and windows in a horizontal nailer system

[bigmish]

I'm planning to using a horizontal nailer system to skin my frame. This is straight forward enough however I became confused as the best way to proceed once I began to add doors and windows. Here is a quick sketch of how I invasion framing for the window opening on one side of the house:


after that I would lay foam and 2x4 stiffeners from the ground up around the framed openings as follows:


Does this make sense as a way to do this? Any thoughts or alternatives?

Thanks, mischa

[Jim_Rogers]

Generally when a horizontal nailer system in going to be used in a timber frame I place a stud each side of the door openings, like this:




And then change my standard spacing to the height of the window rough opening to make the header and sill.
Here I have placed some 2x4's for the window rough opening and these nailers are 4x4 and the door posts are 4x5.

Everything has to be tied to the main frame above and below the window opening.

Hope this helps.

Jim Rogers

[bigmish]

Jim, If I'm understating your drawing right, it looks like the insulation would be between the timbers. I've created a cross section below of how would imagine this system. I've read that placing the insulation between the timbers is very energy inefficient as gaps form as the timbers dry-out and shrink. Am I understanding your system correctly?


The following cross section illustrates how I've been envisioning skinning the frame in cross section:

[Jim_Rogers]

The frame in my drawing above was to be a shed/barn/workshop. I know he intends to do vertical siding, probably board and batten. How he intends to insulate it, I'm not sure of. But I know he probably will insulate it as he had planned on a wood stove in one corner with an exterior chimney.

Your concerns about insulating between the timbers is correct as there will be shrinkage.

There are many ways to do insulation, all or many of them are correct.

Again, just for clarification, each timber is named based on it's position in the frame. A post is a vertical timber, a beam is a horizontal timber. A 2x4 stud is a vertical timber, a 2x4 could be used as a horizontal timber known then as a nailer. (I know I'm being extreme about names, but it helps to understand drawings if they are labeled correctly).

If you intend to place 2x4 (studs) horizontal outside of the frame and create an external wall for enclosing your frame, this would be one method that works. And it does not get effected much by shrinkage as posts don't shrink much in length if any at all.

And also, your window and door locations have to be secured to the frame somehow. If they are only in the external wall that's fine. But your upper drawing shows the windows only being held up at the bottom with nothing attached to the top, and it's hard to tell whether or not they are inside the frame or external to it.

Here is another view of the same frame:




Here you can see the door and window framing are within the frame and are attached to several members of the frame to hold them in place. Some are simply toe nailed and some are cut in.

Hope this helps.

Jim Rogers