Double 2 x 12's or single 2 x 12 on gable wall ??

[TimboTractor]

Building a 40 x 72 pole barn and am using double 2 x 12's on the side walls. Bolted to the top of the 6x6 posts with a notch cut in them so the second 2x12 is flush with the wall girts. Thinking about using a single 2x12 for the gable walls bolted to the face of the 6x6 post.
Do I need double 2x12 s on my gable ends? How about over my doors, on one end I'll have a 16 x 11 roll back door (garage door type) and the other end will be a 10 wide by 11 tall door, on 12 foot walls.

 

[cruz54982]

IMO the peace of mind for the double strength far outways the cost of a couple more planks. doubleing gives the grain of the boards in different places making it less apt to sag . I made the mistake of using a 6x6 post over a doorway that now sags a bit .I later got the explanation of different grains from a local builder.

 

[KennyG]

On the gable ends there is no need for doubled plates because you aren't supporting any weight, like the side walls where you are supporting the entire roof trusses.

Over the doors is a different story. Over the doors you want as much stiffness as you can get. With 6x6 posts, I would fill between the posts with 3 laminated 2x12s with 1/2 inch plywood between to bring it out to 5-1/2".

 

[s219]

Are you using roof trusses? If so, there will be no load on the gable walls that requires a header. You can simply use 2x4 girts there and then make a basic header to trim out any doorways. Look at another pole barn for example.

The main reason for the headers on the eave walls is to carry the load from the trusses to the poles. There is no load like that on the gable walls.

 

[s219]

On the gable ends there is no need for doubled plates because you aren't supporting any weight, like the side walls where you are supporting the entire roof trusses.

Over the doors is a different story. Over the doors you want as much stiffness as you can get. With 6x6 posts, I would fill between the posts with 3 laminated 2x12s with 1/2 inch plywood between to bring it out to 5-1/2".

I agree totally, but note that the stiffness needed over the doorway is in the lateral direction, so you can just as well use a 2x4 laid flat (i.e., with the 1.5" dimension vertical) nailed to a 2x6 or 2x8 vertical. That stiffens the opening in the lateral direction more than doubled vertical 2x lumber would. The 2x6 or 2x8 gives plenty of surface for nailing siding and/or door tracks to.

 

[Rock knocker]

What do the plans say?

 

[ace10]

What do the plans say?

+1

Should be right there in black and white, or black and blue.

 

[HillStreet]

I would definitely use the doubled headers on the end, considering the openings for the doors, plus the weight of the 10 x 11 door.

 

[rtimgray]

I would definitely use the doubled headers on the end, considering the openings for the doors, plus the weight of the 10 x 11 door.

I'm not sure from the OP said in his first post what type of door, but if they are regular garage doors, there won't be any weight on the header of the door anyway - at least on on any of the ones that I have installed. If it's a sectional, then based on the height I'm guessing the track will be suspended from the bottom of the trusses.

Now if it is a roll-up door in a canister, that might be different, but the ones that I've seen installed here in our plant all install on the jambs of the doorway, not attaching to the header other than to just give the canister cover a little support.

If the above stated is true, there's really no need for a header as such, because it's not going to support either the roof or the door - all those loads will either be on the door jambs or trusses.

If there are indeed plans for the barn, sure, go with what they say, especially if inspection and codes have to be honored. If it's being built without plans, like in an unicorporated county area (like where I live), do whatever you think is best.

Good luck and take care.

 

[TimboTractor]

It's in an unincorporated area and is an agricultural building, but it will still be enclosed. The doors will be a sectional garage type door. Seems like I can get the most height clearance with this type of door. And yes, the track will suspend from the trusses. I didn't really want to cut into the taller gable posts for a double 2 x 12 installation. I'm thinking I may just notch the two inner gable posts so I can double up the 2 x 12's over my door openings only. Otherwise, I'll have to face nail a 2 x 6 to the post to support the back 2 x 12, which will narrow my door width by 3". And will probably nail a 2 x 4 along the bottom of the 2 2 x 12's over the door openings to give it front to back (lateral) stability....which will lower my door height by 1.5 ".