When is a portal frame not needed for a garage door?

[andyaz]

Typically when I draw a garage I just default to the portal frame since they're usually narrow in my area; not much meat on either side of the door. I have one coming up that is, for once, not. It's a 30x30, 11' ceilings, with a 14' door centered on the gable end. I'm having a hard time pointing to where in the code book this is OK, given that I'm using the WSP bracing method (fully nailed off sheathing) all around the garage. Is this just a building-department discretion thing, or is there some table/prescriptive technique in the IRC that I'm not finding? The closest thing I found is the minimum length of bracing- it looks like 4'- which in this case I think is OK since I have 8' on either side.

"R602.10.3 (Supp) Minimum length of braced panels. For Methods 2, 3, 4, 6, 7 and 8 above, each braced wall panelshall be at least 48 inches (1219 mm) in length, covering a minimum of three stud spaces where studs are spaced 16inches (406 mm) on center and covering a minimum of two stud spaces where studs are spaced 24 inches (610 mm)on center. For Method 5 above, each braced wall panel and shall be at least 96 inches (2438 mm) in length whereapplied to one face of a braced wall panel and at least 48 inches (1219 mm) where applied to both faces. For Methods2, 3, 4, 6, 7 and 8, for purposes of computing the percentage of panel bracing required in Table R602.10.1(1), theeffective length of the braced wall panel shall be equal to the actual length of the panel. When Method 5 panels areapplied to only one face of a braced wall panel, bracing percentages required in Table R602.10.1(1) for Method 5 shallbe doubled. "

 

[steveray]

Unless you have insane wind, it's not required at that door.....

 

[steveray]

Use the simpson wall brace calculator to figure out how much bracing you need and then it sounds like you can use CS-G for a min. 24" panel....And you have 16' of bracing...

 

[BN4537]

See R602.10.2.2 and Table 602.10.5 for CS-WSP.

You have braced wall panels within 10' of each corner and not more than 20' apart in the middle. Your wall is over 12' high and your opening is only 10' tall, meaning your braced panel lengths are only required to be 48" by Table 602.10.5. You are way overkill with just standard continuous sheathing, without even looking at a garage method.

Assuming A, B, or C seismic zones.

 

[andyaz]

Use the simpson wall brace calculator to figure out how much bracing you need and then it sounds like you can use CS-G for a min. 24" panel....And you have 16' of bracing...

Thanks, didn't know about this tool.

See R602.10.2.2 and Table 602.10.5 for CS-WSP.

You have braced wall panels within 10' of each corner and not more than 20' apart in the middle. Your wall is over 12' high and your opening is only 10' meaning your braced panel lengths are only required to be 48". You are way overkill with just standard continuous sheathing, without even looking at a garage method.

Honestly I think it's a case of "When you got a hammer, everything is a nail". I haven't done a garage with more than 2-3' on either side in a long time, the portal frame has just become a reflex

 

[steveray]

Thanks, didn't know about this tool.


Honestly I think it's a case of "When you got a hammer, everything is a nail". I haven't done a garage with more than 2-3' on either side in a long time, the portal frame has just become a reflex

I try to get everyone out of portals as they are rarely done correctly....