[Malcolm]

I'm going to build an 8x10 patio deck. I noticed some people use just concrete blocks for footings due to there really not being a frost line. It would be much easier to do it this way. I'm just wondering if that is recommended or up to code. I'm not sure if I'm going to do a floating ledger board or affix it to the concrete block wall. I'm leaning towards the latter. What are your thoughts on footings in Florida?

 

[Aggie67]

Run it by the town or county. Most town and county web sites have guidance on-line for this sort of thing.

 

[Californiadecks]

According to the IRC that a lot of states use for code, R.105.3 there is no code for decks under 30" that's not used as a main egress. In other words if you have more than one egress you don't need a permit nor inspections. I use precast piers often and have been for 14 years without issue. I too have no frost line. I do 500,000 dollars worth of decks per year. I would have no problem using piers. The one thing you may want to watch for is expansive clay.

 

[Californiadecks]

I would like to add that it's best to bury them somewhat below grade to prevent any washout under them. The difference between my climate and yours, is we rarely have rain. Just something to consider.

 

[Malcolm]

I would like to add that it's best to bury them somewhat below grade to prevent any washout under them. The difference between my climate and yours, is we rarely have rain. Just something to consider.

What size stock would you use for the ledger boards and floor joists (8x10 deck)? What type of concrete anchors (and what size) do you recommend for the ledger board attached to the concrete block?

 

[Californiadecks]

What size stock would you use for the ledger boards and floor joists (8x10 deck)? What type of concrete anchors (and what size) do you recommend for the ledger board attached to the concrete block?

8' joist span, I use 2x8 joists at 16" o.c. with a 2x8 ledger. I'd put a 1/2" titan bolt every 24" staggered 2.5" up from the bottom and 2.5" down from the top. If you can't get Titan bolts, redheads are sufficient. Titan bolts are great bolts, I strongly recommend them. Just drill a 1/2" hole and put them in like lags.

Titan bolts aren't designed to be used with washers. Fyi.

 

[Californiadecks]

You can get away with 5" anchors. That pic reflects 6". When you drill for those anchors, drill twice as deep as the anchor. Trust me it helps tremendously.

 

[Malcolm]

Thanks

I have a few more questions if you don't mind.

How far below the door threshold should the final decking material be? How many posts would you use on a 8x10 deck?

 

[MushCreek]

I built a large deck in FL using those deck blocks. They never moved or settled after some 20 years. I also used them under my shed here in SC, and they haven't moved, either. Just make sure that they're on firm, undisturbed soil.

Decks are usually about a 4" step down, but I don't think it needs to be that much. As for posts, I would think 6 would be plenty. You would probably be OK with 4, but I like to overbuild things.

 

[Californiadecks]

Thanks

I have a few more questions if you don't mind.

How far below the door threshold should the final decking material be? How many posts would you use on a 8x10 deck?

How high off the ground is finish decking?

If it's high enough you can give it an inch below the threshold as long as you're using planking and water can escape. If you put a beam on top your posts. I'd go with at last a 4x8 beam with a one foot cantilever over each post. This makes post to post span only 8'. If you can do a drop beam that would be good. That way you can cantilever your joists one foot over the beam as well.

To do a 4x8 drop beam, with 2x8 joists 1.5" deck boards,1"below threshold, you will need a minimum of approximately 18" clearance below your threshold.

 

[Californiadecks]

That would allow you to only use 2 pier footings if the other end is ledgered to your home. If you wanted you could use three front pier footings and use a 4x6 beam.

I also want to add you can use a built beam as well. Exchange a 4x8 with a double 2x8 or 4x6 with a double 2x6.

 

[Californiadecks]

Or if you really wanted some insurance you could go with 3 piers in the front no matter what size beam you use.