Building a freestanding deck under porch

[ScottsGT]

I have a 16 X 16 screened in porch that is about 8' above ground, built into an L section of the house. The two walls are poured concrete basement walls the deck sits above.
Below it is a dirt floor. It's currently a storage disaster and I want to pull everything out this fall and start over.
I'm giving some serious thought to building a deck underneath from pressure treated lumber that will sit as low as possible above the dirt. Nothing really heavy is going on it. About the heaviest thing will be my riding mower. The rest will be shelves around the two walls holding inexpensive items I hoard that can sit in the elements. Car parts, etc.
Not planning on attaching to the poured concrete walls, since there is no need. Just a floating or free standing floor. Thinking of a few 4X4 posts anchored into concrete every few feet.
Will 2X6 construction built on 16" centers topped with the 1X6 planks be sturdy enough?
Trying to keep costs low as possible.

 

[rsanter]

Sounds good
Why not a compacted gravel floor?
How about building a couple storage sheds to keep things out of the weather and then shelves on the outside of the sheds that can store things that don't care about weather

Bob

 

[Greeny]

Why not pavers directly on the dirt? Any type of elevated deck or floor is going to be at least 10 inches high, eating up your limited headroom.

If you're dead set on an elevated deck, why not just set your 4x4 posts on pavers? The 2x6 frame would be fine, but I would either go with actual decking, or 2x6 for the decking. Or less than 16" centers. In my area, the 2x6 is cheaper and sturdier. (All PT) I don't see the need to set posts in concrete for what will basically be a floor just 10 or so inches high.

 

[Zeke]

It will be drier if a deck, good air circulation below is a must. Not too close to the dirt.

1 x 6 boards are not enough 16" OC for the mower. Might even be a little springier under foot traffic. I'd use a min of 5/4 wood. The more stout the lumber the longer it will last. We don't see much (if any) 1 x 6 treated around here. Do you have that? The floor joists certainly are available as well as posts. Precast concrete piers buried almost to the top with a girder holding up the joists is about as low at you can go unless you put piers under every joist. And to save on piers, I'd suggest lagging into the walls on the 2 sides. A bolt every 3 feet should be plenty under the circumstances.

Here's a low deck solution:

 

[ScottsGT]

I guess 5/4 is what I was referring to as the decking. I like the precast concrete piers. I'll give that some thought. But yes, with all the humidity and bugs we have, just about anything and everything around here is available in PT. Maybe the mower area I can do on 12" centers? Not being a deck, I can also open the gaps on the decking to allow better airflow.
Thought about the gravel or pavers, but over time they so move around a bit. I'm afraid any shelving might shift and fall.

 

[captain14]

To add onto Zekes picture above. Attach hardware cloth at the edges and bury along the perimeters. You don't need an uninvited guest to burrow underneath and worse is to expire.

I have a rabbit that has been staying under my shed built like that and he was driving the dog crazy since he couldn't get to the rabbit. The rabbit dines in my garden and I have seen him run back there under the shed.

 

[Zeke]

It doesn't sound like much sun gets in there, but you can also put down a barrier cloth and a layer of gravel over that. Protecting against varmints is a very good idea. Listen to the captain.

 

[James-W]

How about building a couple storage sheds to keep things out of the weather and then shelves on the outside of the sheds that can store things that don't care about weather.

Bob

I like this idea better than a deck. Not saying a deck is a dumb idea, I just think this idea has a lot of merit to it and would fit all your needs, and more.

 

[ScottsGT]

Basically, it's protected from above and on two sides, with the third side being covered with my deck. One side is open and 8' of that has lettuce work. I thought about building a lock up box for yard tools, but I'd prefer the entire space prepped for a good start at organization.

Hadn't even given thought about critters getting under a deck. Something to seriously consider.
Might look into gravel and pavers.