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I am building a 24 by 30 cottage with 2 x 4 exterior walls, 8' high. I want to have a clerestory style roof with the front 1/2 of the house having a roof pitch of 3/12, and the back roof 6/12, which will leave space for clerestory windows facing the front. How should I construct the center wall, which will be holding both roofs? It will be 14' high in total. Can I build this wall with 2 x 4 or should I use 2 x 6? Can I build a 10' wall first, topped with 2 2x12's to support an opening of 12' in the wall, and then put an additional 3' high section on top to complete the height for my tallest roof?

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  • AFIK the roof could be constructed without a load bearing interior wall. The framing experts here can tell you the pros and cons of that, but I just want to make you aware that I think this is possible. A lot of tract houses are built with trusses that are supported entirely on the exterior walls in which the interior walls are non-load-bearing partitions. You can also have a hybrid where most of the roof employs trusses but one room (say with a vaulted ceiling) relies on a load bearing interior wall on one side and reduced length trusses also are supported by the interior load bearing wall. Aug 17 '18 at 12:08
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    I can imagine the framing experts saying that if you intend to divide the interior space along the line of the clerestory windows, the best design is to make that interior wall a load bearing wall. Aug 17 '18 at 12:19
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    I’d caution you on using 2x4 exterior walls. Not because of the structural concerns, but because of the energy concerns. Most codes require a certain R-value for the exterior “envelope” and it’s extremely difficult to get it with 2x4 walls. Also, just from a practical issue, the energy savings will easily pay for the extra cost for 2x6 studs in the first year or so.
    – Lee Sam
    Aug 17 '18 at 16:23
  • @JimStewart Seems like it would be difficult to enjoy the clerestory windows without a load bearing interior wall. I guess trusses doubled up at 4’ o.c. would work and still give a vaulted appearance. Or some kind of “rigid frame” steel construction would work, but difficult.
    – Lee Sam
    Aug 17 '18 at 16:29
  • @Lee Sam, I presume 2x4's would be sufficient for the clerestory wall, but if there was a lot of plumbing in that wall would it be better for it to be 2x6s? The downside would be that the doors through that wall would have to have the larger jambs for 2x6 framing. Aug 17 '18 at 17:55
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There are of course lots of ways to accomplish this. Since the ends of the rafters from both roofs (rooves?) need support, at different levels, it's a bit of a challenge.

It would be easy to construct the center load bearing wall with balloon framing methods. (Actually the whole structure is very well suited to balloon framing.) However since balloon framing is seldom used these days, not many people know how to do it, and it can be difficult to get permits / approvals etc. But it's very well suited to multi level challenges like this.

The picture below shows a pretty straightforward way to frame it with familiar, standard platform framing. If you look closely you can see that there are really two built up columns in the center. Inside, you could have a double wall - one side built to support the front roof, one side built to support the back roof. That is probably the simplest, most straightforward way to go.

If you wanted the interior wide open, you could also have the built up columns supporting beams, one to support the front roof and one to support the back roof. The beams would have to be carefully sized to support the roof load across the span, and buying / building them and getting them in place would be a big job.

Clerestory Roof Wall Framing

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You might benefit from Sean's Shed.

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  • Thank you for all the info, very helpful. But still not sure if it is ok to build the wall 10 ft high with 2 x 4s, then top with a support beam of two 2 x 12s to span an opening of 11 feet or so, then build the wall up 3 more feet to create the clerestory? Would this be structurally sound and bear the load?
    – Betty
    Aug 17 '18 at 22:33
  • The calculations to establish the design of these beams would depend on an exact scale drawing. You cannot do it by a few lines of text. For one thing there is too much chance for miscommunication. Aug 17 '18 at 22:54
  • Another question...I intend to put the small cottage on pressure treated 6 x 6's, in the ground 4.5 feet (below frost line). I have been told by builder that the posts have to be a max of 8 ft apart. With the measurement 24 ft deep, and the center supporting wall at 12 ft, do I need to have a rown of piers directly under that wall? That would space them at every 6, just want to be sure that is necessary. At every 8 ft as recommended, there would not be a row directly under that wall...
    – Betty
    Aug 18 '18 at 10:47
  • I believe that there should be a foundation pier directly under each vertical support of a main load bearing wall, and the piers under the vertical supports might have to be heavier than the others. You would place extra piers below each vertical support--you don't have to space all the piers so that one row would fall directly under the wall. Aug 18 '18 at 11:08
  • You have not said what the plan is for the floor. Will there be beams across the piers and joists on top of the beams? Do you have a builder that you trust to do this job? Are you just checking up on his plan for the construction? Aug 18 '18 at 11:17

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