Poolhouse Challenges

[XR250]

This is a mainly open poolhouse with a gable roof. Has some solid walls attracting and resisting wind. I am trying to avoid visible bracing, flagpoled columns or moment frames.
For wind N-S, I can use the 5'-8" long closet wall as a fulcrum and cantilever the roof diaphragm from that. The loads and ratios seem manageable.
For wind E-W, I'd like to use a 3-sided diaphragm. Again, the loads seem pretty small.
Does this seem reasonable?

 

[JStructsteel]

seams reasonable.
Can you use the 8x8 with the MPBZ base for some resistance?

 

[XR250]

seams reasonable.
Can you use the 8x8 with the MPBZ base for some resistance?

I refuse to use those as i don't trust them or like their flexibility or aesthetic.

 

[JStructsteel]

I refuse to use those as i don't trust them or like their flexibility or aesthetic.

Oh ok.

 

[TRAK.Structural]

I think the concept looks reasonable. Some things I would be trying to sort through to make sure the load path is complete

1. What will you use for chords for the cantilevered section in N/S direction?
2. How will the collector truss in N/S direction fasten to the SW?

I think 1 SW on the plan south side would really help you out if the client is willing to adjust the concept, even if its only 1/2 the col bay spacing in length.

 

[KootK]

Works for me. Proportionally, I've done a lot more building with a lot less wall.

I've been burned a few times trying to use shear walls around fireplaces for various detailing reasons. Just something to keep an eye on in the early stages.

 

[phamENG]

Makes sense to me. Doesn't fit in the NDS requirements perfectly, but those are seismic requirements....not uncommon to take a few liberties with them when dealing with wind - especially something as small as this.

 

[Tomfh]

Seems reasonable.

I would be insisting on some sort of identification inside the walls making clear they are shear walls and may not be altered without engineers approval.

 

[Eng16080]

I was about to say no to this on the basis of it not meeting SDPWS, but maybe I'd reconsider now that I see the loads are very small. Concerning that, are those loads really accurate? They seem low (at least based on what I normally deal with).

 

[XR250]

Works for me. Proportionally, I've done a lot more building with a lot less wall.

I've been burned a few times trying to use shear walls around fireplaces for various detailing reasons. Just something to keep an eye on in the early stages.

It is a wood framed fireplace, but Yea, I actually drew out the fireplace and it is an issue. i am going to have him pull it in and use the back wall of it as shear wall. Thanks!

 

[XR250]

I was about to say no to this on the basis of it not meeting SDPWS, but maybe I'd reconsider now that I see the loads are very small. Concerning that, are those loads really accurate? They seem low (at least based on what I normally deal with).

Seems reasonable.

I would be insisting on some sort of identification inside the walls making clear they are shear walls and may not be altered without engineers approval.

I am not a fan of that. At what point do we stop being the "structural police" Not sure why this would be more of an issue on this structure than any other. The lack of redundancy?

 

[XR250]

. What will you use for chords for the cantilevered section in N/S direction?
2. How will the collector truss in N/S direction fasten to the SW?

1) Cont. beams on top of the columns/wall top plates with blocking between the rafters.
2) The "truss" will have a double rafter that continues down as shed roof and integrates into the top of the shear wall.

 

[Eng16080]

I am not a fan of that. At what point do we stop being the "structural police"

I wasn't trying to police anything. Just thought the loads seemed a little low, that's all. No disrespect intended.

 

[XR250]

I wasn't trying to police anything. Just thought the loads seemed a little low, that's all. No disrespect intended.

Ha, I was referring to TomfH's post about marking the shearwalls.
Like I said - mostly open and 90 mph wind, exp B so only about 12 PSF

 

[Eng16080]

Ok, makes sense. That's why it's so low. I was thinking there was a 16 psf minimum.

 

[Tomfh]

Not sure why this would be more of an issue on this structure than any other. The lack of redundancy?

Yes, removing any of these walls would make the building completely unstable.

Lightweight shear walls look like regular load-bearing walls to most people, including many builders. The common practice is to remove these walls and add a beam instead. Most of the time this doesn’t cause problems because there are plenty of shear walls left. But in this case, the designer is pushing the limits of stability with a three-sided diaphragm.

I’m just talking about writing in red sharpie on the studs or the wall lining, or something like that.