How I finally solved the crumbling porch problem — steps that actually worked

I did somethig similar last summer when I replaced our old cedar platform. I went with GoliathTech piers because our soil is basically heavy clay and digging four-foot holes for concrete was a total nightmare. Those piers cut my prep time down significantly, though I found that getting the leveling plates perfectly aligned on a 450-square-foot frame took way more fine-tuning than I expected. Regarding the costs, I ended up closer to $18k because I stuck with Trex Transcend in Island Mist. I realy like the idea of using TimberTech seconds to save cash. I had a few boards with minor surface scratches that I just hid under the stairs or used for the outer rim joists. It really stretches the budget when you are dealing with such a large footprint. I used butyl joist tape on the tops of my pressure-treated 2x10s before laying the boards down. While that walnut and hickory seal mix sounds like it will look sharp, I found that the tape gives me a bit more peace of mind against rot in the long run. Since you are planning for a gas fire pit, make sure you double up those joists in that specific area. I did not do that at first and had to crawl back under there to add extra support once the weight of the furniture and the pit started to cause a tiny bit of bounce.

Have you ruled out the possibility of that Ready Seal failing on the pressure-treated frame? If the lumber was still holding moisture from the yard, those oils ussually just sit on the surface instead of soaking in correctly. Also, with a 600-square-foot freestanding build, have you accounted for lateral sway? Helical piers are great for vertical loads, but a footprint that big can sometimes develop a shimmy if you don't have some serious diagonal bracing underneath. It woud be a shame to have that gas fire pit shaking every time someone walks across the boards.

Helical piers sure beat the old days of humping 80lb bags of Quikrete out to the backyard and mixing 'em in a wheelbarrow til your back snapped. Back then, we’d just sink PT posts right in the dirt and pray for ten years before the rot set in.

If you're using hidden fasteners on those seconds, watch out. If your joists aren't dead straight—and they never are with the junk lumber at big box stores—those clips will drive you crazy. I still prefer face-screwing with a countersink bit; at least you know the board isn't walking when the seasons shift.

Running the gas line for that fire pit before you lay the last of those TimberTech boards is a lifesaver. I used a flexible CSST line and strapped it right to the joists; way better than trying to fish it thru later.

On my 500sf build, I also swapped out the standard wood stair stringers for some pre-cut steel ones from the local yard. They cost more upfront, but they don't sag or rot, wich was usally the first thing to fail on my old setups. Plus, they're way easier to get level when you're working solo.