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weedyacres

So we're designing a big ol' deck....

weedyacres
14 years ago

Last summer we added a sunroom onto the back of our house, which overlooks a lake. Here are before and afters of the construction. Sunroom is on the left; breakfast nook and master sitting room are in the turret on the right.


We're now ready to DIY build a deck out back, and I'm working on the design phase. I've been poring over back posts here, have read a couple books on deck building, and have been through the tutorials on sketchup so I can mock up the structure.

Today I paid a visit to the "permit store" to see what local codes require, and all they did was give me a binder with the IRC and point me to a table where I could read it. So I think I'm a bit on my own with this (well, on my own with all your help :-)).

This all faces due west, and all our trees are tiny, so we get full sun. Tentative plans are to have a deck + pergola in front of the sunroom, and deck in front of the turrett, with a step down to a lower area with a fire pit.

So here are a few starter questions for the design phase:

1. Ledger boards #1: As you can see, the brick facing extends down over the block that forms the crawl space. Assume we need to attach the deck ledger through the brick into the block? (I've only seen instructions for ledgers that have exposed block or siding, so want to verify).

2. Ledger boards #2: Where do I put ledgers for the part of the deck that goes around the turret? Just one on the outermost length and have the rest of the joists cantilever over the beams? Or around all the sides?

3. Ledger boards #3: For the pergola in front of the sunroom, my research says I shouldn't attach a ledger above the slider/sidelights/transom, so I need to go freestanding. True?

4. Pergola posts: The pergola will be roughly 15'x20'. Does code require/do you recommend 6x6 posts or are 4x4s okay? If I'm strategic with my post spacing, can I use the same posts for pergola support and beam support (I will do the appropriate load calculations)? For pergola supports that can't be strategically spaced, do they need to sit on piers or can they be bolted to beams or joists (again, subject to load calculations)?

5. Pier load/depth: I don't know my precise soil bearing capacity. Can I use 1500 psf (the most conservative listed in the IRC)? I don't know our frost line either, but the footing requirement on the addition was 14" deep and 24" wide. Does that mean that a 24" deep pier (code minimum, I believe) is sufficient?

Thanks in advance for your coaching on this.

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