Architecture - Deck Extension
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Jeff123
03-13-07, 12:58 PM
I posted this on the decks forum, but wasn't getting much response so I thought I'd try it here. It really is more of a design question.
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Just wanted to get some thoughts on this. I may need an engineer.
This is what I currently have: 10X12 pressure treated deck about 37" high. 2X8 joists 16" oc running perpendicular to the house and attached to ledger board attached to the house. At the other end the joists sit on two 2X8 beams bolted on either side of three 4X4 posts parallel to the house about 8' away from the house. The three posts are evenly spaced across the width of the deck (the 12' dimension). So the current deck is cantelievered (SP?) over the beam about 2'.
I want to build a small 4X12 extension on the deck (basically extending the deck 4 feet out with the same width as the current deck). The extension will be about 7" below the current deck (about 30 inches high). From my measurements, what would work perfectly from a design standpoint would be to use joist hangers to hang 2x8 joists on the beam of the current deck, extend them out the four feet past the current deck, and then rest them on beams attached to posts sunk in the ground. So the new joists would be about 6' - 2' under the current deck and 4' for the extension. This would save me digging 2 or 3 post holes which would be required if I built a free standing deck as the extension.
I hope I've described this accurately. I'd like any comments on whether this seems structurally sound. Code in my area requires decks to carry 40 psf evenly distributed live load with footers at least 30" below grade (Newport, KY).
Thanks,
Jeff
Draw out your new design and submit it for a permit.... I'm sure the permit will be approved/rejected based on their knowledge and experience. We can't answer your question properly because we don't know the inspectors/permit office involved. The worst that can happen is that they reject your design - and you have to dig those extra holes.....
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Just wanted to get some thoughts on this. I may need an engineer.
This is what I currently have: 10X12 pressure treated deck about 37" high. 2X8 joists 16" oc running perpendicular to the house and attached to ledger board attached to the house. At the other end the joists sit on two 2X8 beams bolted on either side of three 4X4 posts parallel to the house about 8' away from the house. The three posts are evenly spaced across the width of the deck (the 12' dimension). So the current deck is cantelievered (SP?) over the beam about 2'.
I want to build a small 4X12 extension on the deck (basically extending the deck 4 feet out with the same width as the current deck). The extension will be about 7" below the current deck (about 30 inches high). From my measurements, what would work perfectly from a design standpoint would be to use joist hangers to hang 2x8 joists on the beam of the current deck, extend them out the four feet past the current deck, and then rest them on beams attached to posts sunk in the ground. So the new joists would be about 6' - 2' under the current deck and 4' for the extension. This would save me digging 2 or 3 post holes which would be required if I built a free standing deck as the extension.
I hope I've described this accurately. I'd like any comments on whether this seems structurally sound. Code in my area requires decks to carry 40 psf evenly distributed live load with footers at least 30" below grade (Newport, KY).
Thanks,
Jeff
Draw out your new design and submit it for a permit.... I'm sure the permit will be approved/rejected based on their knowledge and experience. We can't answer your question properly because we don't know the inspectors/permit office involved. The worst that can happen is that they reject your design - and you have to dig those extra holes.....