Deck Skirting 'On' Ground Options?

Hey DIYers ..

I've been studying the forums here, and endlessly searching the web. I'm about to embark on building a wooden deck over my roughly 20' x 15' concrete slab that is my back porch.

The overall plan of doing so seems very simple. The idea is to make it a two part process and build the deck with 4x4 attached posts to later add a covered pergola over top. So far, I've found every bit of information on how to do this -- perfection.

Here's my dilemma though -- on the back end of the concrete slab is the house -- no problem there, to the left is a HVAC unit and a path leading outward -- again, no issue with any skirting. The right side has a downward slope and the front goes directly out nearly level with the ground.

Essentially, the front right side is at ground level, and the back right side is actually about 3" lower than the bottom of the slab (meaning I can see the dirt below the slab in the back).

My 'idea' was to trench out the ground around the front and ride sides of the slab and build the skirting to go 1/2" out past the slab (for drainage) and essentially have it sitting in the trench, which would give it a finished look all around. I figured some quick gravel in the trenches would allow for any additional drainage, but then ultimately, the PT would be 'touching' the ground area just outside the trench..

Does anyone have any insight or ideas on how to do this, and make it look good without sacrificing the wood damage over time? .. While the front of the slab is no bother, that right side with the slope is going to be an issue making the front and side tie in together, and still covering the major slope.

 

How about using the vinyl or plastic type decking boards to make the skirting? It won't rot. Trex solid decking cuts and attaches just like a regular board.

 

The concern is how it would look with the regular PT boarding?

 

If you buy the gray trex the treated boards will gray pretty close to the trex color. They would actually be smoother than the treated wood and look somewhat like a concrete border around the deck.