How to install windbraces video is on our YouTube Channel
Below are examples of structures with cross-ties, bars going across the peak for larger structures. These are optional to reinforce the structure. Please see the supplemental Cross-Ties page in the installation guide as well as additional notes below the photos
We’ve had a number of questions regarding cross ties being missing from orders. This isn’t the case, and is done on purpose because the last cross tie interferes with the end cover, so we ship the orders “short” on cross ties to compensate for this. We are sorry for any confusion this has caused and are happy to help you with any other installation questions you may have.
Cross ties, also known as collar ties, are a horizontal bar in a structure which ties the left and right side together. They are usually 3’ to 4’ down from the peak. The purpose of cross ties is to add load strength to the structure. Many people look at cross ties as a nuisance because of lost head space but they have a three fold benefit.
- By forming the triangle at the peak you create benefit for the dead load which is usually snow load. The top can not come down when the sides can not spread.
- By tying the left and right sides together, you create strength for the live load, commonly referred to as wind load. When the wind blows from the left, the right side holds it from pushing inward and vice versa.
- Most importantly, it decreases the rocking motion which can stress a building over time.
- The cross tie can also supply a very useful support area for things that need to be suspended.
It is important to remember that when you spread out the load you create strength.Photos & Video: Purlins, Windbraces & Crossties
Norm will be speaking on Saturday morning at the Guelph Organic Conference at Guelph University. We are eagerly anticipating getting to see many of you either at the workshop or the trade show. Below is an overview of what Norm will be speaking about. Please contact us if you have any further questions.
The purpose of this workshop is to share some of my 40+ years of experience to save you some grief and expense. This workshop is an expansion of part of last year’s workshop “Greenhouses 101” which is on our website.
We will be covering the three forces which are exerted on a building: Up, Down and Lateral. These forces will be looked at in the context of aerodynamics and weather. Examples of each problem will be given and preventive measures to be used.
Some basic principles of engineering – how going wider and/or higher becomes exaggerated
Security of your building starts with proper anchoring. How much anchoring is enough or too much?
How is stability affected when the anchor point is not at the ground?
How does structure shedding rain affect the holding power of anchors?
How does recent excavation have on holding power?
Down force is commonly referred to as snow load. The most commonly asked question is “how is the structure rated for snow load?”
A worst case scenario is a combination of freezing rain, snow, rain and wind.
The issues with an uneven snow load – all on one side or all on one end
Issues of snow sliding from a higher building to a lower building
Shape and slope are important to good snow shedding.
How does a structure get evaluated for strength?
Going from wind load to snow load, shape and size do matter.
Proper ways to remove snow and or ice from a building.
Uplift and Lateral forces are not the same but very interrelated
Comparing the profile of a structure to an aircraft wing
What effects are there when the cover area is expanded by going higher or wider?
How does aerodynamics change for multiple units side by side?
What is the minimum space requirement between structures?
How does orientation affect the structure?
Forces on a structure with no cover
What constitutes a good wind break?
We hope you can come out and ask any questions you have face to face with Norm. It should be a great day!