How would you frame this?

[JamesW84]

32x64 stick frame with 18' walls. The pointy thing on the left of the building is actually a 17' wide lean-to, I just didn't get it all put in the drawing. I originally wanted 12' wide doors, so I had the stem walls poured with 12'3" wide openings. Got it framed and most of the trusses up and a strong wind blew it down, so now I'm back to the drawing board before I begin again.

I have a building permit. My plans were simple 2x6 studs 16" o.c.


Left side is the old way. Right side has the 5' shear walls on each end.

After some research and reading about shear walls, I've found that my tall 64' long wall (the high side on my mono slope will be basically 28 feet from the ground to the top of the roof on that side), will make it difficult for the short walls to hold it with a strong wind.

The recommended ratio for a segmented shear wall is 2:1 (18 ft wall = 9 ft of shear per section), but it can be stretched to 3.5:1 with reductions in shear value.

That being said, a guy a work who knows a lot of framers said that I don't need to worry about any of that and I can just run a bunch of braces from wall to wall and diagonally and I'll be fine. The problem is that with a 32" wide section, The angle of the 2x6 brace nailed to the outside of the studs is at like a 70 degree angle, which 45-60 degree angles are recommended.

This is what he's talking about:

Would you do like he's saying or do the 5' shear walls, plywood inside and out with blocks and reduce the 12' wide doors to 10'?

I really want the 12' wide doors, but I don't want my building to collapse.

An engineer wants $2250 for plans. Another said around $1000, but never got back to me with a full proposal. I've studied enough that I'm confident I know what the engineer will say.

I think I'd like to avoid Steel, but if I have to hire an engineer, I might consider steel to make my doors 12' wide.

 

[red61cj5]

The trusses were blown down, or the entire framed building? Was there any sheathing in place, or just the stick frame? Also, was there any temp bracing in place? Sounds like just bad luck at a vulnerable stage of construction maybe?

 

[GMCGarage]

Google Simpson Strong wall. you might need a portal frame at the short walls.

 

[matt_i]

I would suggest a couple of things...

1...look at the Simpson 16 ga flat strapping. CS-16, choose this one over the CS-16-R, the latter has 14' pre-cut lengths although there's enough still joined to be in a coil. I would *much* prefer metal strap over wood strap due to the ease at which the end grain of a wood strap will give out under high loads. One caveat is because the flat strap has no compressive strength (it easily buckles) you need to apply in in an "X" pattern.

2. You can gain shear, directionally, by using thicker plywood, using plywood both inside and outside of the studs, using X-bracing inside and outside, more nails into the sheathing, use something like Loctite 8X polyurethane construction adhesive to attach your sheathing. A min value would be #10d nailed 6" on center along every panel edge and every 12" across the panel field.

3. Its unreasonable to think that the small walls are the only thing that's going to resist shear. In other words use more of the whole endwall to be involved. Check out this sketch to see how you can use the strapping to help the top of the lower endwall to be better involved.




3. Make sure the trusses are also involved by more than just their dead weight. There's the classic Simpson H1Z uplift connector but I'd also think about taking a GRK-RSS screw or a timberlok screw of about 6" long and drive it upwards, thru both double-plates, inside-center of the wall, and into the bottom chord of every truss, both sides of the buildiing, not just the tall-walll. There's also the possibility of using the flat strap, wherever possible, to start on a stud and bridge over the top plates and hit a vertical on the truss, so your uplift is even better-connected to the anchor bolts. I would make damn sure that I didn't have a horizontal joint in the plywood that exactly matches the top surface of the top plate. Put that area in the center of a panel if at all possible.

Hope this helps with some ideas.

 

[Glory]

Is steel not an option? A small number for HSS columns would be fast and simple. If not, I’d go with Simpson strong wall.

 

[JamesW84]

The trusses were blown down, or the entire framed building? Was there any sheathing in place, or just the stick frame? Also, was there any temp bracing in place? Sounds like just bad luck at a vulnerable stage of construction maybe?

I think one of the trusses let loose and took it all with it. Yes, it all came down. I was 20 ft away working on post holes for the lean to. Snap and it was down in 5-10 seconds. The only lateral strength I had was ONE 2x4 running the length of the wall and some 2x4 bracing out into soil with rebar holding it through a drilled hole. I should have put sheathing or more 2x4 strapping on as I built, but I thought that would make it harder to plumb. Because the walls are 18' high, building sections and standing them is difficult, so I did a lot of it one board at a time with my brother's help.


I've read about Simpson Strong walls. I've been researching the different wood structural panel shear walls/portal frames and I had all but decided on using as thick as I could find (3/4 most likely) plywood inside and out with blocking on the short walls. I was going to put 2 rows of 10d nails 2" on center on the edges and the field...that gains a bunch of shear strength per the Wood Frame Construction Manual.

Steel could be an option, but like mentioned, I'd have to have an engineer design it.

 

[JamesW84]

looking at the simpson strong walls again...looks like as long as I use large enough hold-downs and large enough anchor bolts, my 3/4 plywood option & blocking on 2x6's would be stronger?

 

[Glory]

looking at the simpson strong walls again...looks like as long as I large enough hold-downs and large enough anchor bolts, my 3/4 plywood option & blocking on 2x6's would be stronger?

Not even close. I am referring to the steel strong walls.

https://www.buildsite.com/pdf/simpsonstrongtie/Steel-Strong-Wall-Shearwall-Product-Catalog-1461480.pdf

 

[bczygan]

Do a proper engineered shear wall, or be prepared to pick up the pieces again.

Bill

 

[The Tool Tyrant]

No matter which way you choose to go, the load path has to transfer down to the footings. That being said, if you don't have sufficient anchorage from the footings connecting the shear wall to the slab, you still haven't solved the problem.
Hilti, Simpson a couple of other manufacturers make 2-part epoxy for installing all-thread anchors, which has much higher withdraw load ratings than wedge type anchors. They do require a minimum distance from the slab edge as the can blow out the side of the slab if located too close.

I would then use a 3x6 bottom plate for shear nailing. Block at 4', 8', 12' etc, run the sheets horizontally, nailing all edges to create a continuous diaphragm. Do NOT run the sheets vertically as the 1' filler piece you would need to add does nothing to aid the diaphragm. Use Simpson A35F clips @ 16"o/c to tie the top plate to the bottom chord of the truss. Personally, I would do this if it were mine...and I'd sleep well at night.

 

[JamesW84]

My total calculated shear load for each short wall is 12,896 lb. This is what an engineer would have to design for - I'm assuming the shear of the studs and all other components are already figured in.

Total Wind Load ASD Capacity for the 24" wide by 18 high Simpson Steel Shear Wall is 1875 LB.

Total Wind Load ASD Capacity for the 24" wide by 18 high Simpson WOOD Shear Wall is 1890 LB.

Total Wind Load ASD Capacity if I framed it myself using 19/32 plywood blocked and 4" spacing =2700 Nominal = 1350 ASD x 2 (one sheet on each side) = 2700 ASD per linear foot. 2 feet of that would be 5400 LB.

The problem is, it has to be at least 5 ft wide to meet the aspect ratio of 3.5:1

Simpson's walls must be so low because they've been de-rated due to Height/Width Ratio


Steel:

Wood:

SDPWS 2015 Table 4.2B (Nominal Capacities must be converted to ASD by dividing by 2)

 

[brownbagg]

just use plywood

 

[TRWham]

It seems you are trying to get all your shear resistance at each end of a 64' long structure. Could you add some braced wall lines somewhere inside? Maybe some internal buttresses at some interval along the walls? If you are doing any storage or work benches on the walls you would not lose much usable width but your building might stay up.

You might also carry the end walls past the side wall into the shed roof area to pick up some braced wall length.

 

[OccupantRJ]

Did you clean up the vomit after it went down? That would be sickening.

 

[ard]

Surprising to have a permit but no engineering....

Any internal construction planned? A second story and/or a mezzanine can be used to create a ridged diaphragm, the braces the walls- tie that to the foundation with shear panels. All wood. Plywood.

Wouldn't it have been cheaper to have an engineer from the get go? Call around, you can get a structure engineered from thousands of miles away....

 

[RocketScott]

It's going to be hard to use the simpson strong walls now that the foundation is poured

 

[couch67]

+1 on engineered plans. Asking for a lot from those narrow walls on the front, I'd sleep better myself that the design was going to hold in the long run.

Might be too much of a concession but have you thought of going to one wider door (16') instead of two?

 

[JamesW84]

It seems you are trying to get all your shear resistance at each end of a 64' long structure. Could you add some braced wall lines somewhere inside?...

You might also carry the end walls past the side wall into the shed roof area to pick up some braced wall length.

I've thought about that. I plan actually would like to have a "work room" under a 16x32 mezzanine running in the back corner of the shop. I mentioned that to the engineer I called and he said that wouldn't do anything to add shear I don't think he was thinking about running diagonals. I need to look more into this. I'd have to go to perforated shear walls on the ends and do a segmented shear wall on the inside. The only thing is the floor is only 5" thick, so I'll have to look up and see how deep the anchor bolts would have to go.

Surprising to have a permit but no engineering....

Any internal construction planned? A second story and/or a mezzanine can be used to create a ridged diaphragm, the braces the walls- tie that to the foundation with shear panels. All wood. Plywood.

Wouldn't it have been cheaper to have an engineer from the get go? Call around, you can get a structure engineered from thousands of miles away....

Just simple hand drawn plans for permits around here as long as it meets code. 2x6 walls 18' high meet code. There's only a couple counties around here that even have building code enforcement/inspections. I would have thought/now wish they would have noticed the lack of shear walls and flagged me.

Would it have been cheaper to have engineered plans before...maybe, but hindsight is always 20/20. Good idea on the engineered plans from miles away, didn't think of that.

 

[JamesW84]

Might be too much of a concession but have you thought of going to one wider door (16') instead of two?

Yes, but I don't think I want that because some guys say it's harder to get cars in and out, which I would think it would be with a 16' door on a 32' wide wall. I'd want at least a 20 ft door.

I really want 12' wide doors on the front. The back I'd be ok with 10's. I could price a simpson moment frame, but I'd end up having to rip concrete out and repour to get it anchored, I'm afraid.

 

[matt_i]

Just wanted to clarify...at the point of fail, was this total stick framed without a single sheet of plywood on it? I think that's true by reading above.....it seems like its getting a little out of hand placing all of the blame on the short garage door sidewalls having almost zero racking resistance at that time. If you want the ultimate sidewall, go with a welded frame of 1/4" steel plate facing a 3" channel box-frame, use much larger & deeper epoxy anchors, like 7/8" or 1" anchors.....

I also feel like you can do a pretty good job of using the outboard posts to help out. Consider the fail where the wind is blowing on the big tall sidewall, to cause the shear/tipover fail in the same direction it also has to tip over these posts. Even though it might not look super elegant consider setting steel posts in heavy concrete piers that are much larger than a sonotube (like 2 yards apiece), use weldment at the top of columns to attach to the wood in several places.

 

[JamesW84]

Just wanted to clarify...at the point of fail, was this total stick framed without a single sheet of plywood on it? I think that's true by reading above.....it seems like its getting a little out of hand placing all of the blame on the short garage door sidewalls having almost zero racking resistance at that time. If you want the ultimate sidewall, go with a welded frame of 1/4" steel plate facing a 3" channel box-frame, use much larger & deeper epoxy anchors, like 7/8" or 1" anchors.....

I also feel like you can do a pretty good job of using the outboard posts to help out. Consider the fail where the wind is blowing on the big tall sidewall, to cause the shear/tipover fail in the same direction it also has to tip over these posts. Even though it might not look super elegant consider setting steel posts in heavy concrete piers that are much larger than a sonotube (like 2 yards apiece), use weldment at the top of columns to attach to the wood in several places.

No plywood was on it. I was going to use 2x4 stringers/girts 2 ft on center parallel to the top and bottom plates to attach the metal to. I didn't put them all on yet.

Your ultimate sidewall idea is something I actually thought of but figured a moment frame would be more cost-effective.

I thought of doing something similar to your steel post idea with wood posts, but wasn't sure how that would look.

 

[RocketScott]

Whoa, pump the brakes

Are you not planning on sheeting this?




Sent from my iPhone using Tapatalk

 

[JamesW84]

Whoa, pump the brakes

Are you not planning on sheeting this?




Sent from my iPhone using Tapatalk

As mentioned, I was going to use 2x4's horizontally every 2 feet all the way up the walls. Since the fall, on the long walls, I now plan to run 2x6's at 45 degree angles from the top of the wall down and from the top of the first truss down; then I planned to run the 2x4's as previously mentioned, but cutting them to fit around the angled ones. The metal would then be attached to those.

The inside of the long wall on the highest side of the truss will have OSB at least on the bottom 10 ft. The long walls will have half as much force applied as the short ones and have no openings, so I'd think the diagonals would work. Otherwise, I could just run the OSB on the inside up to the top of the wall for the first 8-16 feet.

The short walls, my real problem, will have plywood outside and either ply or OSB on the inside unless I find a good deal on a moment frame.

 

[bigdav160]

The diagonal bracing like your first pic needs to go from the top plate to the bottom plate.

Rack it plumb and nail it off. I would still sheath it. Construction adhesive and nailed. Horizontal blocking isn't going to be much help in racking.

 

[JamesW84]

I called the inspector, reluctantly after an engineer told me he didn't want to design a moment frame unless he designed the whole building.

I asked if I could have an inspection prior to setting trusses so that I could frame it with the 12' doors and see what he says. He said they don't usually do inspections before rough-in, but asked if I had concerns.

I slowly asked questions more and more in-depth to gauge his concern.

2x6 16" on center = Good
Engineered Trusses = Good
Purlins/Girts on the exterior instead of ply = Good
30" wide walls on each side of the door = Good
Epoxy in anchors where the J bolts were goofed up = Good
No hold downs put in on the sides of the doors during Concrete placement = Good, just use Simpson HTT5 brackets.



Sounds like I was more worried than him. I'll just do the ends as perforated shear walls and add a segmented shear wall or two inside after final inspection when I do my "room" inside.

Thanks for all of your help.

 

[The Tool Tyrant]

Just remember that an inspector is NOT an engineer, and if it blows down in the next strong wind, you CAN'T sue him.

Just my 2 cents and 32 years of framing experience...those 30" shear walls are not going to win when the wind blows against that 'billboard' sized sail. Best think this over.

 

[JamesW84]

Just remember that an inspector is NOT an engineer, and if it blows down in the next strong wind, you CAN'T sue him.

Just my 2 cents and 32 years of framing experience...those 30" shear walls are not going to win when the wind blows against that 'billboard' sized sail. Best think this over.

Thanks.

I plan to include enough sheer strength per calculations, but I just plan to do it with interior perpendicular (perp to long wall) Segmented Shear walls in addition to my Perforated Shear Walls, which will be the exterior walls with doors. I'll sheath them with thick Plywood on both sides, blocked and a 3" nailing pattern.

Does that sound reasonable?

The perforated shear walls should get me a total of 10,384 lbs of lateral resistance and then I'd need 12 feet of segmented shear wall to pick up the remaining 15408 lbs.

 

[The Tool Tyrant]

James, with 30" wide "shear walls", I'd venture to say rather than "reasonable", it sounds 'wishful'.

Here is another thinking outside the box idea for you, although I would still run it by a structural engineer for calcs. The post at the left side of your drawing...use a wide flange steel beam as a moment post (picture it 6'-8' deep in an 18" diameter hole) with a column cap welded to the top. Run the door header continuous from the WF post to the outside wall. NOW, shear your 30" wide walls as previously mentioned...just an idea.

 

[polexican23]

have you considered using duct tape? or maybe even combining that with some gorilla glue.