Design feedback on open hot tub shelter

[troyp]

I would appreciate any feedback or thoughts on my first timber frame design.  I want to build a shelter over a hot tub that will have vertical siding on two sides, and be open on the other two.  The nearest narrow side is the entry, the large open area will be over the hot tub.

Here is an image and a link to the .skp file:  https://drive.google.com/open?id=1zGfBVVnYra9l7k3be_T1Ge3oGsmRNdnc


Thoughts on any aspect of the design is appreciated, but the two challenges I don't know how to address are the bracing for the short sides and the amount the cross beams should be below the top beam on the low side.

SHORT-SIDE BRACING 
I have high wind and snow loads so want to be sure all sides are well braced.

The space between the posts is 3'4" with 8x8 posts.   The closest narrow side is the "entry" so I don't really want to make it high enough that braces could fit without getting in the way of walking.

I put one 2' brace on the far wall.   To fit two I would have to go down to smaller than 1.5' braces and I would lose quite a bit of headroom on the entryway.

One alternative idea would be to sheath the entire space above the beam tied to the rafter, but not sure about that either.

TENON VERTICAL SPACING
How much should the cross beam's tenon be below the top of the post on the low side?   I started with the top of the cross beam inline with the bottom of the longer beam on the short side.

I have just started trying out my Logosol mill to make a few posts, but haven't started on any of the posts or beams for this ... yet.

I've been reading lots of information on the site and it has been tremendously helpful.  I am just feeling stuck with the side-to-side strength.

Thanks in advance for any help.

   -Troy

[Don P]

Just some random thoughts.

Aspect ratio is a biggie in wind, a low and wide ratio performs better in wind than tall and narrow.

The far end bracing could be an X or stacked X's with a lap at the crossing.

I'd put the near end tie on the lower post and notch it to take the lower plate. A crotch could be tenoned into the tall post in 2 places or even into post and upper plate.

[Brad_bb]

Welcome to the forum.  If you can, please put where you're from in your profile and it will show up in each post so we know where you are. 

The one thing I noticed is it looks like you're using 6x6 for posts and 4x6 for other frame parts, but the rafters look like 2x.  How about at least some 3" or 3.5" x 5" or 6" rafters?  The rafters shown just look skinny compared to the frame.  You want to make it look like one frame.

[troyp]

...

Aspect ratio is a biggie in wind, a low and wide ratio performs better in wind than tall and narrow.

The far end bracing could be an X or stacked X's with a lap at the crossing.
...

Don,
Thanks for your thoughts.  It got me rethinking the need to keep that side open.
If I close off both sides with X or stacked X's I can also lower the roof.  The goal is to provide wind and weather shelter while getting in and out of the tub and overhang part of the tub.
Let me rework it a little.
  -Troy

[troyp]

Welcome to the forum.  If you can, please put where you're from in your profile and it will show up in each post so we know where you are.

The one thing I noticed is it looks like you're using 6x6 for posts and 4x6 for other frame parts, but the rafters look like 2x.  How about at least some 3" or 3.5" x 5" or 6" rafters?  The rafters shown just look skinny compared to the frame.  You want to make it look like one frame.

Brad,
I had not setup anything in my profile, so I did.  Thanks for the reminder.  I am in the mountains about an hour out of Denver, CO.   Surrounded by lodgepole pines and had to take out several to put in a garage.  That's what got me here.
Then had the need a bigger chainsaw ... ended up finding a Stihl MS361 and a Logosol Timberjig.  The fun begins.
For the design on the roof, you are absolutely right.   This had started out as a traditionally built shelter and is transforming into Timber Frame.   I hadn't redone the roof, yet.
I do think 3.5" x6" rafters with 2" purlins/planking would look much better.  I hope/plan to put standing seam metal roofing on it.
  -Troy

[paisan8]

i thought the knee braces go in as pairs to oppose each other. if your worried about head room you might consider bracing to the rafter . i just built a timber frame shed roof and did just that. you need a way to hold the rafter to the beam though i used a steel plate.

 

[troyp]

Paisan8, they do need to go in pairs.  I was running out of room.

SO ... thanks to all the suggestions I've done a few things:

• Made the shelter lower and wider (aspect ratio). The height of the top of the low long beam is now 6'8"; which moved the lowest point of the front brace to just over 5'7".
• Set the cross beam on top the low side post, then half-lap the long beam across it
• Closed off another side, so now three sides are closed with bracing, girts, and vertical siding.
• Redid the roof with bigger rafters and decking (timber frame approach instead of typical stick-frame)

That let me put in standard pairs of braces on all four walls.  We will get a bit more shelter and lose a little of the night sky.  But seems like a good trade-off.

Here is a link to the new .skp https://drive.google.com/open?id=1GysfXoAbH0woPzZ3puCzuwpCtFusg4bl

And the updated design.

[Bandmill Bandit]

Could use Clear Pellon sheeting for the roof sheeting and not lose any sky view. Just a thought.