Stratton Bracket for mounting awning ledger over 2″ cork facade?
pnw_questions
| Posted in General Questions on
Would it be possible, or rather sensible, to use this bracket to mount an awning ledger over a 2″ cork facade ?
They say it “Bolts directly against most types of siding; Vinyl, Aluminum, Steel, Wood and Masonry”.
The awning would project 4 feet and be supported by two posts.
Thank you
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This strikes me as more of a question for your engineer, but from a control layer perspective, I don't see any issue. I would use stainless steel bolts to reduce the thermal bridging and would be sure to seal it to the water control layer on the exterior and air control layer on the interior.
Thanks for your reply. We've got grandpa who's a civil engineer :) but it's a small single story backyard project without a structural engineer. I heard from an employee at the cork distributor this afternoon and unsurprisingly they said cork doesn't have a very high compressive strength. They wouldn't recommend resting things like a ledger against cork. I can respect the limitations of the material. I do remember seeing people put strapping over exterior cork insulation and attaching cladding, though there are probably other factors at play in that scenario compared to this.
I may be misunderstanding, I thought perhaps it was the fasteners only (lag bolts, structural screws, or bolts) that would be bearing the load of this bracket/ledger rather than the cork?
https://pastratton.com/installation
That the structural fastener just travels through holes in the cork but they're anchored in wood, and the bracket is fully support by the fastener, it's just adjacent to the cork or whatever type of cladding, not depending upon it? That may be a sort of wishful thinking on my part.
pnw_questions.
The Stratton Bracket is designed to allow drainage between the ledger and cladding, but your main problem is dealing with the shear forces on the bolts going through a thick layer of soft cork. I suspect any connection you use is either going to need blocking or spacers behind it, or as the Maine Deck Bracket does, deal with those forces by its shape.
Thank you for your reply. I think I may have misunderstood how the Stratton bracket works. I had thought perhaps the bracket would be adjacent to the cork but not supported by it - that the whole load would be on the structural fasteners (that merely pass through holes in the cork). https://pastratton.com/installation
I did see the Maine deck bracket when researching options. At first I thought it would be perfect, but when reviewing the details found it's pretty big for us. We have 2" of cork facade and I believe it projects 5". We need a "mini Maine". The width is 8" - not sure that would work for us and how much we'd need to do internally to accommodate that width. It's a single story, a shorter wall with a limited amount of space above the door level. After a certain number of extra steps are required, it begins to feel like there are fewer advantages over our original plan of an awning completely supported by posts.
pnw_questions,
I think you can deal with the compressive problems of the cork by making a mini-Maine Bracket out of a variety of materials. My choice would probably be 1" galvanized pipe to run the fasteners through. If you wanted a more elaborate version you could add flanges to each end (see attached photo). Blocks of PT lumber would work, or pieces of HDPE plastic.
As Joshua said, at the least you should run any solution by your Building Inspector.
Oh, interesting! How would the flangeless 1" galvanized pipe work? Is the pipe merely a tunnel for a structural fastener in that scenario, or is the pipe structural as well? What would be happening at either end of the pipe?
With a flanged pipe, would it be installed like the Maine bracket? Where you attach one end to the building, flash and put cork over/around, and then attach the ledger to the other end? Except, would you still run a structural fastener through the ledger, through the pipe, and into the building?
Plain wood blocking was the first thought we had, because we have a door buck/blocking thing going on. But I was hoping to not have to interrupt the cork with wood, and to avoid having to detail around that. At some point in this project, I developed a sort of psychological block to putting wood on the wall and flashing it, and to extra cutting of the cork. That's how I ended up researching other options like brackets.
I have a question regarding the Maine bracket. I was curious why they say to remove a section of the sheathing to install? I hadn't noticed that before with other brackets. Is it because people may have flimsy sheathing?
pnw_questions.
The pipe or the solid alternatives are there to counteract the lateral compressive forces the fastener exerts. Without a flange the pipe may crush both the sheathing and ledger slightly, which is why flanges might help. I would still use a fastener with a flanged pipe.
I'm sorry I don't know why they suggest removing the sheathing. I've never used a Maine Bracket. They make sense to me if you are using exterior insulation you don't want to interrupt, but not just because people have trouble properly flashing a deck ledger - which I've never found particularly difficult.