Lateral Bracing Covered Patio
Lateral Bracing Covered Patio
(OP)
Hello all,
I have a quick question regarding lateral bracing for a covered patio. In the past I have typically used knee bracing at simple covered patios or even cantilever steel columns/grade beams for larger patios or decks. Are there any other standard options for lateral bracing of structures of this type?
I have a designer who says he has consulted on projects using a knife plate as 'bracing' but he cannot provide a detail or any other info. Has anyone used any other mode of bracing such as knife plates for this application?
Thanks in advance.
I have a quick question regarding lateral bracing for a covered patio. In the past I have typically used knee bracing at simple covered patios or even cantilever steel columns/grade beams for larger patios or decks. Are there any other standard options for lateral bracing of structures of this type?
I have a designer who says he has consulted on projects using a knife plate as 'bracing' but he cannot provide a detail or any other info. Has anyone used any other mode of bracing such as knife plates for this application?
Thanks in advance.






RE: Lateral Bracing Covered Patio
RE: Lateral Bracing Covered Patio
To be a little more clear, the intent on this project is to use a wood post and wood beam. I would like to add wood knee bracing for lateral support of the structure but the client does not want that 'look', nor do they want to pay for a steel column/grade beam system. The designer's suggestion is to use a knife plate at the wood post to wood beam but I have never seen that used as an option to knee bracing. Can someone please let me know if that is an acceptable alternative, and if so can you please advise on the appropriate detail/design?
Thanks so much.
RE: Lateral Bracing Covered Patio
The knife plates I used were 1/2" steel plates with 8x8 wood posts. Two moment bolts through the knife plate and a cross bolt each side and parallel to the knife plate between the moment bolts.
Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.
RE: Lateral Bracing Covered Patio
RE: Lateral Bracing Covered Patio
Unless your client is OK with an ugly knife plate connection or wants to spend the money for upgraded detailing, I'd think your best bet is to hide the structural stuff in the ground.
RE: Lateral Bracing Covered Patio
Another option if you have a raised deck is to brace it below deck level thus achieving the cantilevered column system without the embedment.
RE: Lateral Bracing Covered Patio
I would definitely go with the cantilevered column system but the issue is that this new patio column is located about 1 foot from an existing pool wall and would add surcharge.
Which leads me to my next question. If I go with the cantilevered system with deepened footing, how can I determine how far to move the post away from the existing pool so that we are not adding surcharge?
RE: Lateral Bracing Covered Patio
RE: Lateral Bracing Covered Patio
BA
RE: Lateral Bracing Covered Patio
FYI, the client is ok with a deep footing or moving the post away from the pool. I just need to determine how far to move it to see if that is a feasible option.
Thanks again.
RE: Lateral Bracing Covered Patio
Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.
RE: Lateral Bracing Covered Patio
Laterally brace the canopy to the building and just vertically support the canopy at the column.
RE: Lateral Bracing Covered Patio
As for loading, due to the low R value, I'm coming up with a load of about 2.3 kips laterally at the column, so I dont know that a plated moment connection would work.
RE: Lateral Bracing Covered Patio
However, this may not be easy to achieve depending on the elevation of the two roofs.
Do you have a section or elevation showing the difference in levels?
BA
RE: Lateral Bracing Covered Patio
RE: Lateral Bracing Covered Patio
Just tie it to the "L" shaped house structure. Don't worry about cantilevered columns as they are not needed here.
Mike McCann
MMC Engineering
RE: Lateral Bracing Covered Patio
I now understand what you mean. I can definitely tie the canopy to 2 sides of the existing strucure. What I am unsure about is how the canopy diaphragm is supported laterally on the other sides. In your approach what is going to keep it from moving laterally if there is no resisting element at that corner? Not arguing with the approach, just want to make sure I fully understand so I can justify this through design.
I have attached a link for a section view.
Thanks.
RE: Lateral Bracing Covered Patio
RE: Lateral Bracing Covered Patio
I understand the methodology and had thought you were assuming a rigid diaphragm. My only concern is achieving rigidity for the wood diaphragm. Also not sure if you noticed, but the client is using retractable shades which means there is a 12'x12' hole in the roof diaphragm. Do you think that will be an issue? I dont have much experience with rigid diaphragms.
RE: Lateral Bracing Covered Patio
RE: Lateral Bracing Covered Patio
It is much appreciated.
RE: Lateral Bracing Covered Patio
Whether you are designing knee braces or knife plates, cantilevered or pinned posts at their base, or roof diaphragms and tying them together, you might want to get a local Structural Engineer involved, who knows what he/she is doing, and can actually see the details you are dealing with and working around. We can't see them from here, but knife plates, properly done, will offer some (loose) moment resistence btwn. a beam and column. You've been offered several possible solutions. It sounds like your designer/drafter uses the terms 'designer & consulted on projects' kinda loosely, and should be told what to draw for these critical details, if you want them to work well. These darn drafters and their CAD's (or are they cads?) can draw anything; engineering it and building it to stay standing is another matter altogether. And, I don't mean engineering from a distance like your project to Eng-Tips, and back again.