New High Tunnel

[Cole_Robbie]

Thanks for that picture as an example. We'll do some bracing, but the specialty clamps required are expensive, so it depends on how much money Mom & Stepdad are willing to spend.

[PureHarvest]

I didn't look at your original pics, but worth is right. However, if you get those angle braces right and make them longer, that keeps wind from pushing the end walls and racking your frame.

image.jpeg

[PureHarvest]

My problem with wind load in the past was when I got it from the north or south, which pushed against the end walls. So angle braces would have helped me. Without them my HT got pushed so the bows looked like this when viewed from the sides: / / /
Instead of: l l l
Concreting the endwalls sockets would have helped too.

[Cole_Robbie]

Originally Posted by PureHarvest

Like this? Just to deal with wind load:

Attachment 56192

The small interior struts on that sample pic, I'm noticing they are at an angle. Should my angle be steeper because my roof is steeper? I'm thinking mine would meet the frame perpendicular and come down at a 45.

[Worth1]

Originally Posted by Cole_Robbie

The small interior struts on that sample pic, I'm noticing they are at an angle. Should my angle be steeper because my roof is steeper? I'm thinking mine would meet the frame perpendicular and come down at a 45.

Cole may I step in here for a minute.
You need to look up scissors truss I have been sitting on my hands for a while now.

Here is but one example an other one is simple cross bracing.


Do NOT brace it the same way you would a dome roof.

Worth

[PureHarvest]

Worth, wouldn't that be more for snow load vs end wall pressure from wind?

[Worth1]

Tie bracing at point A together and it isnt going anywhere.

[Worth1]

Originally Posted by PureHarvest

Worth, wouldn't that be more for snow load vs end wall pressure from wind?

No both.

Worth

[Cole_Robbie]

Thanks Worth, that is interesting. I would have to figure out how to hold it together with carriage bolts and band clamps. Your second pic looks a lot easier.

[PureHarvest]

Like this?

image.jpeg

[PureHarvest]

If there are no braces running from the end wall to the next few hoops, how does it resist racking?
All the tech specs I find show some kind of bracing running in the direction like in the last pic I posted.
I'm not saying u are wrong or I know better b/ c I certainly don't. Just trying to wrap my head around this.
The truss or scissor bracing, I've been told, was for snow load and/or to hold the weight of interior crop supports like vertical strings for trellising.

[Worth1]

Very important you secure point A.
Look at the structure in your mind.
if the wind pushes the side walls at an angle the two lines at point A have to slide and move.
If they cant move the walls cant move.
https://www.google.com/url?sa=t&rct=...vb5XaDpQU0d1RA

[Worth1]

I haven't gotten to the side bracing yet.

Read the link above.

Worth

[PureHarvest]

Originally Posted by Worth1

Tie bracing at point A together and it isnt going anywhere.

I follow how the wind will not push it over from left to right as you view that pic.
I don't see how it will help when the wind is blowing directly at that pic.
Sort of like you could have a sturdy bow like in your pick, but how it attaches to the next bow and the next is what confounds me. Obviously the purlins and ridge pole connect each bow together, but I'm told the purlins alone won't keep it strong enough.
Sorry if I'm frustrating u, I'm slow to visualize some things.

[Worth1]

Originally Posted by PureHarvest

I follow how the wind will not push it over from left to right as you view that pic.
I don't see how it will help when the wind is blowing directly at that pic.
Sort of like you could have a sturdy bow like in your pick, but how it attaches to the next bow and the next is what confounds me. Obviously the purlins and ridge pole connect each bow together, but I'm told the purlins alone won't keep it strong enough.
Sorry if I'm frustrating u, I'm slow to visualize some things.

You are not frustrating me at all I love this stuff.
As I said in the above post I haven't gotten to the other bracing yet.
And I am trying not to insult cole.
I just dont want to see it collapses because as it stands now it surely will I can promise that.

If it were me I would look at the price options with cross bracing not only on the wall but the roof.

I am leaning toward cable and turn buckles.

Plywood laid sideways so it was 4 feet tall would greatly help or even wood runners down the sides with wood bracing.
There are a thousand ways to do this.

right now I dont even know if the scissors truss is the best idea.
It might be better if it was inverted so the big ends were on the bottom.