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I have a question about stick framing around a garage door opening. My contractor has attached extra boards on the studs (the boards with the red marks in the photo). My initial thought was they are temporary, but there are a lot of fasteners for a board that would be getting removed. So maybe it is permanent? Anyone have any ideas (my contractor apparently doesn't work Saturdays :whip: so I can't ask him today)? If these are permanent, then I will need to add extra boards to support the sheetrock.

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Just guessing, but I would suspect it is just additional support for a long span. Garage doors are pretty wide. :dunno:
 

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These are the boards that will support the door track and torsion springs. You will NOT cover these with sheetrock, but rather but it against them.
 

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What Kenny said ^^^^^^^^^^

Normally there would be 2 x 4 surrounding the door opening, but the wider surround will give the door installers an extra margin to compensate for your doors width. Yes, you may have to scab in some 2 x 4's before drywalling.
 

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These are the boards that will support the door track and torsion springs. You will NOT cover these with sheetrock, but rather but it against them.
Bingo! :thumbup1gif:
 

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..thats a pretty long span especially if that is a load bearing wall.....i would be tempted to put plywood on the inside also ....but he may have put more than enough on the outside...

patience sir....he has a ways to go before he is finished :good2:
 

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..thats a pretty long span especially if that is a load bearing wall.....i would be tempted to put plywood on the inside also ....but he may have put more than enough on the outside...

patience sir....he has a ways to go before he is finished :good2:
Looks like there is a header there that has been furred out. Could be adequate but without knowing all the details it is just guessing!
 

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Discussion Starter #8
These are the boards that will support the door track and torsion springs. You will NOT cover these with sheetrock, but rather but it against them.
Thanks! I just went out to my house garage to look. They finished these boards with white metal trim. I never noticed it before. It’s the little things, like these additional boards to support the doors, that I didn’t even consider doing the framing myself!

..thats a pretty long span especially if that is a load bearing wall.....i would be tempted to put plywood on the inside also ....but he may have put more than enough on the outside..
I don’t think the plywood would add any structural benefit in this case.

As a structural engineer I am finding it very difficult to leave my response that short and not elaborate. I just don’t want to type out an explanation that nobody gives a flying &%@$ about. I am happy to go into more detail if there is interest (hell i might in disprove my own theory as I am trying to explain it)

patience sir....he has a ways to go before he is finished
But I want it now!
 

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I don’t think the plywood would add any structural benefit in this case.

As a structural engineer I am finding it very difficult to leave my response that short and not elaborate. I just don’t want to type out an explanation that nobody gives a flying &%@$ about. I am happy to go into more detail if there is interest (hell i might in disprove my own theory as I am trying to explain

No need to expand your response to my simple statement of opinion.........I am a PE and Owned a C/I Design build firm for 30yrs now retired so i dont think your going to over detail me but it wasnt intended to be more than a simple observation and statement based on a single picture
 

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I didn’t mean anything pompous with my post. I know all too much what it’s like try to asses a situation from one or two pictures.

Out of curiosity what is c/I? I have never seen that acronym before.
 

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Commercial/Industrial ..(very little wood framing)..i dont take things personal to many years of dealing with the industry for that...i do enjoy commenting on construction threads though hopefully in a helpful way ...:thumbup1gif:
 

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Well, I"m curious

Since ignorance can be cured and I'm in a state of semi-ignorance on this one- I'll ask why plywood wouldn't add structural strength.

It's seems to me that anytime you add strength to the vertical plane you increase the ability to handle vertical loads. In addition, in my mind if not in the real world I would think plywood on the inside would increase the strength to handle a horizontal force from the outside such as a ROPS being left up.

I would think if you had plywood inside and out, it would be a hell of a strong structure as effectively you would have a very deep box beam as long with the studs becoming internal gussets.

I am curious as why my thinking is wrong, it might keep me from making an incorrect assumption sometime.

Thanks.

Treefarmer
 

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Discussion Starter #14
Since ignorance can be cured and I'm in a state of semi-ignorance on this one- I'll ask why plywood wouldn't add structural strength.
Sober-me waking up to last night's drunk-me internet boondoggles :banghead:

It will add strength, and it certainly wouldn't hurt anything to add plywood, other than the wallet. My thoughts were that wall sheathing is primarily for transferring horizontal loads to multiple studs. When the load is perpendicular to the wall (i.e. wind blowing directly at the wall) the sheathing will work just like plywood over floor joists. The bigger role of the sheathing is for loading parallel to the wall (look up shear walls if you want further reading); basically the sheathing will prevent the 2x studs from collapsing/folding over domino style.

For vertical loads, the sheathing does not carry any significant portion of the load. The studs are the stiffer structural elements, and they are a direct path from the top plate to the sill plate. The sheathing will help to prevent the studs from buckling.

When there is a large opening in the wall, such as the case of a garage door, a header beam will be the primary structural element. Below are the three items we discussed above applied to a wall opening:
  • Buckling - The studs above the header are short and are not prone to buckling.
  • Shear Wall - Typically areas near opening are ignored in shear wall calculations. This doesn't mean they do not provide any stiffness, but it is minimal compared to full height walls
  • Vertical Load Transfer - header to posts or double/triple 2x studs
Hopefully this isn't so scatter-brained that it can not be followed. Now back to my cold coffee
 

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Ok, so given your above post; explain I-joists. ;)

The sheathing does prevent buckling of the studs, but to say it doesn't add vertical strength is a major understatement.

In fact, I'd venture the opposite to your theory: The studs keep the sheathing from buckling when laminated into a sheer wall when the load is not transferred to a bearing surface below.
 

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Discussion Starter #16
Ok, so given your above post; explain I-joists. ;)
Maybe I am missing the connection here but I just don't see it. The flanges carry 'all' of the load in tension and compression and the web transfers the load between them via shear stresses.

The studs keep the sheathing from buckling
Alright I will buy into it. In a vertical load application the sheathing doesn't carry any load, but it prevents the studs from buckling. When the wall is acting as a shear wall, then yes, the studs are preventing the sheathing from buckling.

Therefore I will rephrase my statement: I do not think adding sheathing over a header has any appreciable benefit.
Vertical loading: Sure adding the sheathing will increase the lateral buckling strength of the header, if you put enough nails in it. But if this was actually a legitimate concern you would double or triple up the header, or go to a steel beam.
Out of plane loading (i.e. wind blowing directly at the garage door): Yes this will cause weak plane bending in the header (and yes you could increase the thickness/strength of the header by adding sheathing), but the proximity and the stiffness of the ceiling joists will transfer this load to the rear wall. Unless there was a big garage door on the rear wall as well and/or the walls are super tall, there is no reason to consider this load case.
In-plane loading (wind blowing on a side wall): The portion of the wall above the opening will never be a shear wall. The header will transfer the in-plane forces between the shear walls on either side of the opening. If the force being transferred was large enough, it could cause euler buckling in the header (which again, the sheathing would help a little bit). But if the load was this large I probably have bigger issues, like my roof blowing off.

I do appreciate this back and forth. It makes me think about this a lot more than I otherwise would have. Once this is all said and done I am going to nail a piece of plywood up there and take a picture of it just to post here
 

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For sheer walls, you do need to increase nailing density to every 6" edge to edge.

If I was home, I'd shoot a pic of my sheetrock around the overhead door structure plates. I didn't bother painting them and they still look nice. Of course, I love timber frames and post and beam construction, so I like seeing some wood coming out of the finished walls. :)
 

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:munch:


maybe i can add a OPINION (lol) ....if you take away all sheathing you are only transferring loads from the top plate to the bottom plate (door header) of the "wall" in the form of point loads at ~16" on center......when you add the sheathing you are in effect making the wall a X-height truss where the lower plate now becomes a member in tension and the top plate a compression member now making the whole assembly a bearing member....obviously the whole assembly is much stronger in ALL planes
 

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Interesting discussion

Sober-me waking up to last night's drunk-me internet boondoggles :banghead:

It will add strength, and it certainly wouldn't hurt anything to add plywood, other than the wallet. My thoughts were that wall sheathing is primarily for transferring horizontal loads to multiple studs. When the load is perpendicular to the wall (i.e. wind blowing directly at the wall) the sheathing will work just like plywood over floor joists. The bigger role of the sheathing is for loading parallel to the wall (look up shear walls if you want further reading); basically the sheathing will prevent the 2x studs from collapsing/folding over domino style.

For vertical loads, the sheathing does not carry any significant portion of the load. The studs are the stiffer structural elements, and they are a direct path from the top plate to the sill plate. The sheathing will help to prevent the studs from buckling.

When there is a large opening in the wall, such as the case of a garage door, a header beam will be the primary structural element. Below are the three items we discussed above applied to a wall opening:
  • Buckling - The studs above the header are short and are not prone to buckling.
  • Shear Wall - Typically areas near opening are ignored in shear wall calculations. This doesn't mean they do not provide any stiffness, but it is minimal compared to full height walls
  • Vertical Load Transfer - header to posts or double/triple 2x studs
Hopefully this isn't so scatter-brained that it can not be followed. Now back to my cold coffee
Just for clarity- if 1/2" plywood was nailed up and or glued/nailed across a 12' wide opening it would have a cross sectional area of 6"squared. If a 2 x 4 was actually 2 x 4 there would be a cross sectional area of 8" so I see your point of not adding significant strength that way. However, it seems to me the more important point is that plywood would effectively increase the beam (header) depth from perhaps 8 to 10" to possibly 2" which as I recall significantly increases the carrying capacity of a beam. It also changes from a multipoint load (studs hitting the header) to a continuous load although I don't think that's a significant difference. The one thing I don't know is the sheer strength of plywood but I suspect it's very high, at least as high as sawn lumber.

Am I looking at this wrong? I'm curious because years ago we built a pole shed with three built up beams made by nailing 1 x 6's to sections of plywood. Joints were staggered and everything was glued and nailed. They were 70' beam divided into 4 bays and the beams held the rafters. We needed to rebuild a combine engine and hung that from the highest beam and it didn't fail, in fact it didn't even seriously deflect so I'm pretty comfortable thinking that beam depth adds strength. The beams are still there, still solid although some of the poles need replacement.

Treefarmer
 

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Maybe I am missing the connection here but I just don't see it. The flanges carry 'all' of the load in tension and compression and the web transfers the load between them via shear stresses.
Actually, it's under compression across the web.

To disprove your above statement, one only needs to take note that web height increases load capacity. If the top and bottom chords carried all the load in compression and tension as you stated, the web height would be moot.
 
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