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Inner joists vs top joists for my deck

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Apr 19, 2013, 05:08 PM
Inner joists vs top joists for my deck
In designing my deck, is there any reason not to use inner joists/joist hangers inbetween the beams vs attaching them to the top of the beams?

Are there any extra considerations I need to take if I want to do it this way?

Could I still run the joists 16" OC?

If my beam consists of 2 2x8's, would I use a 2x8 as my joist, or could I use a 2x6 still?
Apr 19, 2013, 10:07 PM
Here is a good reference from Fairfax County VA on designing a deck. These may or may not be valid in your area but they probably meet or exceed your local requirements.

Joist sizing all depends on joist to joist spacing and length of joists. A 2x6 joist can't go very far. The spacing and number of posts depends on the size of the deck. I've used a beefed up rim joist when building screened porches on top of decks and the weight bearing on the edge of the deck required the deck posts be at the edge of the deck. This does require longer bolts to hold your handrail posts in place.

General Disclaimer

Any advice given here is general in nature and is not necessarily valid for your given area. If in doubt check with your local codes enforcement department for what is required when doing electrical, plumbing or structural work on your house. Permits may or may not be required in your area and home owners may not be able to DIY some tasks. I have no way of knowing if you have the skills needed to complete the tasks you are asking about, when in doubt seek professional assistance.

My advice may be worth exactly what you pay me for it. :-) For the record I did not stay in a Holiday Inn Express last night.
Apr 19, 2013, 10:32 PM
I briefly opened the link Sparky had and saw the first few pics were of the joists being over the beams. I prefer to build decks that way, and I run the joists long and cut them to length as I install the top boards and work my way out. Then I don't have a short ripped peace of wood or top board at the house or at the end of the deck, I try to keep it whole top pieces.

I have more faith doing it that way rather than hanging the joists on hangers inside the beams. I think it will last longer without splitting wood or spreading.

You can use the 2 x 6 joists, but you have to pay attention to the "span" allowed for the wood you are using, in the area of the country you are building in. Those span tables might be in that link Sparky provided.

And the 'beefed up rim joist' adds a lot of stability of the handrails.

This is my way of doing it -- others will have other ideas as there is more than one way to build a deck. And shape and style can dictate what you do. Plan, Plan, Plan, think, think, Plan, rethink.

Building a custom deck with different levels and angles is fun, but proper planning required. And if you want stairs off the deck, more planning, thinking, etc.