Need help building a deck

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C

Chris

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I need to put a deck and stairs to gain access to the second floor of my shop. It is set up to be an apartment up there but unfinished. Can you guys guide me to make sure it is strong and secured properly? What size ledger and how to make sure it doesn't fall off down the road. What size joists and spacing? What size and how many support posts? I am thinking the size I want us 8 x 12.

Here is a pic of where I want it built.

View attachment 1496413721390.jpg
 
Our standard deck would be built out of 2x10s

On the outside 2 6x6 treated post 11 ft apart 7 ft from the building
On top of the posts a double 2x10 beam then joists at 16" on center. Ledger lag bolted to the rim joist, with hanger for the 2x10 joists

If the deck is solid surface it should be 6" below the floor level and have a slope 1/8 to 1/4 inch per foot. Outside 3 joists can be treated unless you want to add fancy painted wood.

Treated wood deck can be just below the floor level.

Best is to dig down below frost and use a big foot form and tube and fill with concrete to 6" above ground level with post saddles and rebar.

Either way some plywood will have to be removed
 
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Neal’s plan sounds pretty good to me. I would want 3 posts spaced as he said but one in the middle. I would also add some diagonal braces at the top of each post to stop racking along the long edge of the deck.

I would think about making it larger in both directions and using the space below for a car port or storage, if I had a use for the deck above. If I wasn’t going to need a deck just a way to get up to the door. I would go much smaller with just stairs and a landing.
 
Here you'd need to have Y or Z braces on the posts. An uncovered deck would need to be 6" below the door to prevent splashing on the door causing premature failure. Footer depth would be locally determined by your frost line, your permitting department would be able to help out. Your garage footers would be a good guide. All the wood framing would be pressure treated, decking could be pressure treated, composite or wood naturally resistant to rot and insect damage (Ipe or other tropical hardwoods, Redwood).

Ledger would need to be bolted to the structure. The beam would need to be through bolted to the posts, and we'd need three here with 5/8" hex head bolts with washers on both sides, no carriage bolts.

This is one of the better guides I've seen issued by a local government. It likely meets and may exceed your local requirements. But your local codes office would be the best place to confirm it. http://www.fairfaxcounty.gov/dpwes/publications/decks/details.pdf
 
I was going to do just stairs and a landing but just incase down the road someone ends up living there or staying for a long time it would be nice to have their own space. The apartment will be small, my usable space is 14 x 40 and I wanted to keep a 10 x 14 area in the back for storage so the apartment will be 14 x 30.

I will probably enclose the space below the deck at some point for storage. No need for any more parking, I am working on a large pole barn for that stuff. Enclosing it makes me lean more towards a plywood deck instead of 2 x 6's so there is nothing dripping through, then I will have to paint or coat it to waterproof it.

Neal, when you say plywood will have to be removed? can you explain a little better?
 
Here you'd need to have Y or Z braces on the posts. An uncovered deck would need to be 6" below the door to prevent splashing on the door causing premature failure. Footer depth would be locally determined by your frost line, your permitting department would be able to help out. Your garage footers would be a good guide. All the wood framing would be pressure treated, decking could be pressure treated, composite or wood naturally resistant to rot and insect damage (Ipe or other tropical hardwoods, Redwood).

Ledger would need to be bolted to the structure. The beam would need to be through bolted to the posts, and we'd need three here with 5/8" hex head bolts with washers on both sides, no carriage bolts.

This is one of the better guides I've seen issued by a local government. It likely meets and may exceed your local requirements. But your local codes office would be the best place to confirm it. http://www.fairfaxcounty.gov/dpwes/publications/decks/details.pdf

Our local requirements are not the greatest. I am trying to find the sheet they gave me and I will post it
 
You'd be hard pressed to fail if you used the guide I posted. It is pretty good.
 
What's your guys opinion on 4x4 supports? Can always add an extra. I ask because I have several Simpson ties for them already, it would save me 100 bucks
 
I used 4x4's 25 years ago when I put my deck up, that's about all there was available. When it comes time to rebuild it will be 6x6. The 4x twist way to easy.
 
4 x 4's love to twist, curl and check.
Any form of plywood on a deck will fail unless it's covered with a walkable menbrane.
Around here we have to notch the tops of the post, or set them on top of the post.
What type siding is on there?
If it's something like T-111 or Smart Side I'd be spacing out the ledger with PVC lumber blocks, that way there's room for drainage with direct contact to the siding the siding will rotout.
If your even allowed to use lags to attach the ledger to the siding, they must go into the studs not just the sheathing.
Going to need permits for all of this.
 
6x6 post are code. if you are talking about 4x4 saddles for the bottom you can cut slots in the bottom of the posts to fit over them
3 post for 14 ft deck 2 for anything smaller
Deck will be bolted to the building and the plywood will keep it square, no need for angle bracing.

If you are using plywood you want a waterproof membrane
Vinyl done by others or fiber glass, Fiber glass is DIY friendly and fixable

Plywood deck does want to be 6" below floor

The siding is crap so you want to go to the wall behind it so cut cut out enough to bolt the ledger to the rim and and up eight inches above the deck.
Pull the door frame and run the membrane up the wall eight inches and into the door under the threshold.
Replace the door and tuck a flashing behind the siding and house wrap.
Install a paintable wood below the flashing 1" above the deck.

If you are thinking of closing in below do a foundation and build walls, leave space for door.

We are in an earthquake zone and we can set the beam on top of the postd and tie them together with flat straps 12" about 15 nails but notching and bolts work fine.
 
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This is getting complicated. There is no permit process here for it since I am considered AG and the shop is considered a barn to them, they would not even take my money.

The siding is similar to a T1-11. Studs in the barn are 6 inch on center because it was built out of old stage decking. Around here you can build a house out of pallets.

I have worked with lifedeck which is similar to fiberglass for waterproofing.

I want to male this simple as possible as it is just access to a place that won't get used much. I don't mind using 6x6 but I see hundreds of decks on the west coast using 4x4. They have been structural for the last hundred years, that's why I was asking.

If it's easier I will do a 2x6 deck and be done with it.
 
2x6 might be easier, that's up to you..

Treated 4x4 are fresh from the treatment plant, wet, they dry, twist and bend. In some condition that makes them susceptible to failure. 6x6 do all the same stuff but the don't fail.
But the trick is to buy a few and let them dry and take back the ones you don't use.
For a treated deck I would still lower it 6" below the floor.
Removing the siding is important because dirt will get back there and hold moisture and then you have rotten siding behind the ledger.
So I would cut it at 5" below the floor level and 12" below the floor level.
You set the ledger on the plywood lower cut and bolt it to the wall .
Then a galvanized flashing behind the siding and above the ledger under the deck boards.

That allows you to put the deck board right up to the flashing and have a 1" gap from the bottom of the plywood siding.
 
Does it need to be treated? I plan on painting it. All the treated wood I have used since CCA was outlawed out here is junk.
 
Does it need to be treated? I plan on painting it. All the treated wood I have used since CCA was outlawed out here is junk.

2" strips of something over the joists so moist junk doesn't sit on them. That will make them last twice as long.
Or buy underground rated, that's the stuff with rows of knife cuts.

I would only use just painted lumber if it had a roof. But that still could have a life like 7 or 8 years. This is not old growth lumber the old timers used and it lasted for years.
 
Does it need to be treated? I plan on painting it. All the treated wood I have used since CCA was outlawed out here is junk.

If you want to stay out of the siding build a four poster 1" away from the building and just add the angle bracing to keep it stiff.
 
Does it need to be treated? I plan on painting it. All the treated wood I have used since CCA was outlawed out here is junk.

About 6 years ago I did a bunch of fancy posts to hang chain from. I let them all dry for about 6 weeks before I machined them and then gave them 4 coats of black paint before I installed them. They still look great. They were just the cheap treated stuff
 
Around here our lumber is Doug fir, they have been using hemp fir and white wood whatever that is for the treated stuff and it splits and warps like crazy. Doug for is strong and if done right doesn't warp much. I did my deck at my cabin in it in 2010 and painted it and it still looks like new.
 

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