# Header sizing for patio door.



## Daniel Holzman (Mar 10, 2009)

Most manufacturers do not prepare charts specific for headers, because the conditions are variable. Usually an engineer or an architect sizes the header based on total load on the header. The total load comes from a combination of geometry (tributary area) and building code requirements. Your local building inspector can certainly tell you what code you operate under.

Many lumber supply stores (not the big box stores, actual lumber stores) have an on call engineer who will size the LVL provided you purchase the LVL from the lumber yard. That is often the least expensive way to size a header. Getting advice from an internet chat forum from people who have never visited your house, and are likely unfamiliar with your local building code and building inspector, is a poor choice in my experience.

As for the column supports, your building inspector will tell you what you need for support. When I put in my patio French door, the building inspector required a triple stud, a king with two jacks. Local practice may vary.


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## Pittsville (Jan 8, 2011)

First of all, a short disclaimer. Daniel is an engineer, I am not. I'm just another DIY'er, but I'll share what I've learned over the years.

If it's a gable end wall, it's generally not carrying much load. As Daniel mentioned, you can play it safe by speaking with your local building department, an architect or a structural engineer. That said, there is also a prescriptive approach to this issue.

R502.5 Allowable girder spans.

http://publicecodes.cyberregs.com/icod/irc/2009/icod_irc_2009_5_par024.htm

This section of the 2009 IRC addresses your issue. The tables within this section talk about bearing walls, but you can use the same data for non-bearing walls if you'd like. (A little overkill maybe, but it would be safe.) Check with your building department and find out what revision of the code they're using and use the appropriate table(s). The table will provide the size of the header and how many jack studs are needed.

Keep in mind, these tables deal with dimensional lumber only. When you start getting into LVLs, the code is silent. In this case, you would normally have an engineer calculate the size of the beam.


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## cyprusrom (Sep 20, 2013)

Thank you for taking your time to respond guys.
I will give a disclaimer as well. 
I promise if the structure comes down under a violent snow storm, I will not try to sue anyone on any online/diy chat forum. Just looking for an opinion, from someone with experience and/or knowledge.

I looked back on the schematics for the building permit, and the building inspector did specify that I needed 2 "shoulder studs" under each end of the header.
Originally, I was going to use 3 2"x12" dimensional lumber for the header. However, I had special ordered a 20' 1 3/4"x9 1/2" LVL that I was going to use for the ridge beam with 2x8 rafters. I had a change of plans, instead will use a 1 3/4"x 11 7/8" ridge beam with 2x10 rafter, so I can have more space for insulation.

@ Pitsville
The door is at the gable end, and it is a cathedral ceiling with no ceiling joists. I'm thinking the ridge beam support column be supported above the patio door? 

I didn't mention on my original post, the walls are 2x6, I am thinking asphalt shingles for the roof.

Edit:
Pitsville,
Thank you for the table. If I am reading it right, a header made of 2 2"x10" could span 8'5", in a 20' wide building, under 30psf ground snow load? That makes me think bigger,stronger 2x10 LVL should be sufficient. Thanks!


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## GBrackins (Apr 26, 2012)

are you using a ridge beam for your cathedral ceiling? if so would this load be coming down on the header over the door?


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## cyprusrom (Sep 20, 2013)

Hi Gary,
Yes, I am using a ridge beam, and the support column for the ridge beam will be above the patio door. There will be no ceiling joists.


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## GBrackins (Apr 26, 2012)

as Mr. Holzman said, take your design drawings into a local lumber yard and see if they can size your header

Now to your question about jack studs.

According to the Wood Frame Construction Manual, 2001 edition (which is referenced in the 2009 International Residential Code) a 9' opening header should have 3 king studs (full height studs) plus 1 jack stud (sole plate to header) at each end. the four studs should be stitched together to form a built up column.

this will help prevent crushing of the sole & sill plates as well as provide lateral stability of the gable wall.

whenever an opening in a wall is created we must replace the number of full height studs (king studs) at the ends of the opening, i.e., if four studs are removed for an opening we need to place 2 (4/2 = 2) additional king studs at each end of the header (with the 1 king + 1 jack already there). Full height studs provide the resistance to lateral loads whether from wind or seismic.

Good luck!


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## cortell (Nov 27, 2010)

GBrackins said:


> According to the Wood Frame Construction Manual, 2001 edition (which is referenced in the 2009 International Residential Code)...


This is interesting. Never heard of doubling or tripling up king studs. I did a little research on it, as this rule seems to goes against Advanced Framing Techniques and its goal to optimize wood utilization. So, unless I'm mistaken, WFCM allows for a single king stud on each side for openings up to 48" (where winds do not exceed 150mph). So I guess for _most_ window openings, a single king stud is OK.


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## GBrackins (Apr 26, 2012)

the number of king studs is based upon the width of the wall opening. king studs provide lateral stability to exterior walls as they are the connection between the top and bottom plates of a wall. Jack studs are typically hinge points in the wall unless metal connectors are used. Think of rotating the wall 90 so that the stud resembles a beam with the plates supporting the beam (stud). 

I was taught that removing full height studs lessens the resistance of a wall to lateral loads that's why we replace them at the ends of the header.

And yes, for most typical window or single door openings a single king studs is fine.


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## cortell (Nov 27, 2010)

GBrackins said:


> I was taught that removing full height studs lessens the resistance of a wall to lateral loads that's why we replace them at the ends of the header.


That makes sense to me. You'll probably gasp when you this!

http://www.rwfuentes.com/MoreShop/pages/Frame_Complete.htm

Thing is, I wonder if this opening would pass code. Based purely on IRC, I suspect it would, since the IRC is silent on number of king studs in a wood-framed opening. On the other hand, the WFCM would have this framer put FIVE king studs on each end (plus the two jacks)! Overkill? My gut instinct says yes, but I hate to rely on gut instinct. Mostly, I was wondering why most openings, which replace two full studs, are almost always framed with a single king king stud, meaning the WFCM recommendation is mostly ignored. But I found the 48" exception in the WFCM, and wanted to share.


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## Pittsville (Jan 8, 2011)

cyprusrom said:


> Hi Gary,
> Yes, I am using a ridge beam, and the support column for the ridge beam will be above the patio door. There will be no ceiling joists.


I think that the tables in the IRC assume a uniform load will be placed on the header. That ridge beam support would create a point load. Not sure how that would affect your header sizing.

Some lumber yards can take that point load into account when sizing the header. Others may not be able to... Might want to call around and ask. Nice part about lumber yards is that most will throw in the engineering if you'll be buying the header from them.


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