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I’ve got a 40-acre patch of woods and the inclination to build a large cabin myself (I built our current home with success, but am not a builder by profession).
The plan I’d like to use calls for using room-in-attic type trusses 24′ long with a 10/12 pitch and a 12′ wide room within. My problem is that this has to be a do-it-yourself type project and for a number of reasons I don’t see a crane being a part of the building process for me.
Can these things be stick built? I was thinking of layering 2 24′ 2×8’s (for the bottom) over single 2×8’s on the roof slope portion, then using 2×6’s for the interior room shape within the “triangle”. I also thought it might be stylish to beef these up a little, put them 4′ on center and expose the bottom chord to the room below in some fasion.
Can this be reasonably done without consulting a structural engineer?
-RandyR
Replies
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Maybe you should consider doing a story-and-a-half. Could baloon frame it with steel studs. Use one-sided MDO as the sheathing/siding; vertical battens. Then you could make roof trusses.
Kevin
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You essentially are using the truss chords as floor joists. So, what do the span tables say for your wood species and the intended run?
I suspect they will suggest something larger than doubled 2x8s. Since you are trying to do everything by hand reviewing appropriate nailing schedules and glue use might be helpful.
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I have built a garage with room in attic trusses. When pricing lumber, and comparing to what the local truss company could do (Latco) I discovered that they could make the trusses and deliver them for less than I could buy the lumber to frame a room above the garage. My dimensions of the (as my wife grinningly refers to it) tajmahal garage are 38 feet wide, and 26 feet deep. My pitch is 6 in 12, which is a little shallower than yours. The room above is 14 feet wide, and 26 feet deep. The trusses are 2X8 material all around, with 2X4 webbing.
You really find out who your friends are when you need to haul these size trusses onto the top of 10 foot walls! We managed it with 4 (myself included). All fairly stout people, 2 carpenters who had done this sort of thing before, and 2 who had not. The idea was to have a fairly long set of 2X forms making a plane on one wall, slide a truss up that plane, slide it in place, then heave it upright, using 2X4's as push sticks. If you haven't done it (and I hadn't) I highly recommend a day's worth of time of time from a carpenter. You'll learn, and you'll live.
The trusses were set 2 ft OC, they were designed for a static attic load. We just wanted some storage. The room in the attic is high enough in the middle to stand (around 7.5 ft), but slopes to ~5ft at the walls. (Which made for some wasted drywall!) The trusses free span the entire width of the garage.
I trusted the truss comp to do the design work. They have an engineer and 40 to 44 feet is the average free span of chicken houses in Arkansas, and they provide a lot of the trusses for the chicken houses here! I'm not certain, but I think the 5/8 ply on the roof, the 3/4 ply on the attic floor, and 4 full sheets of 5/8 ply used as bracing on each corner of the attic room added some strength. I know I got stronger carrying that stuff up there! The floor seems solid to me.
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I've got a 40-acre patch of woods and the inclination to build a large cabin myself (I built our current home with success, but am not a builder by profession).
The plan I'd like to use calls for using room-in-attic type trusses 24' long with a 10/12 pitch and a 12' wide room within. My problem is that this has to be a do-it-yourself type project and for a number of reasons I don't see a crane being a part of the building process for me.
Can these things be stick built? I was thinking of layering 2 24' 2x8's (for the bottom) over single 2x8's on the roof slope portion, then using 2x6's for the interior room shape within the "triangle". I also thought it might be stylish to beef these up a little, put them 4' on center and expose the bottom chord to the room below in some fasion.
Can this be reasonably done without consulting a structural engineer?
-RandyR