OK, here’s another option: Use PVC boards or pressure-treated lumber to cover the entire open face of the “C” of the steel channels, extending down below them several inches.

After your new flooring is in place (to securely hold the boards in place), drill a 1/4” hole in them every foot or so and stick the foam can tube into them and fill up the voids behind them.

Urethane foam is very sticky, so it will help hold the board, seal the foundation to the ground, and insulate all at once.

Use low expansion foam for that bc you don’t want it to push the whole thing apart.
Great idea, Ray!

If you look for a mix it yourself material get CLOSED cell foam. For this open cell would hold water and be a huge mess down the line

Hello All,

Not to revive an old thread but I have an additional question that came up.

For the purposes of drainage, is it better to get smaller pavers have have more of them or larger ones and fewer?

In other words, some paver are 24"x24" whereas others are 6"x6". My gut tells me it would be better to get smaller ones as there would be more sand filled spaces between them at more numerous intervals and therefore more drainage.

Is this true?

Obviously the smaller the tiles the more "in between" area for drainage. Question though, if all that's under the paver tiles is the original dirt at elevation how good was your drainage then? This drainage won't be any better than that without installing crushed stone and running drain pipes but it will at least keep your feet out of the mud.

That is good to know. I will only look for pavers smaller than 6” x 9” then.

I planned on making a 3 inch layer of crushed stone and 2 inches of sand. I did not plan on any drain pipes though.

Btw: someone told me I need to put fabric between the stone and sand layers to prevent mixing. Is this true?

I wouldn’t be too worried about it but if you have some geotextile fanfic (weed cloth) or shade cloth or even patio screening, go ahead and separate the two.

I have never done that for any of the various stratifications of medium I have done BUT I never thought of it and will from now on bc I have the material and it will work better. How much better, probably negligible in this application, but still, better is better

And, the more joints you have, the more places for weeds to sprout.

I would guess if you are going 2" of sand over 3" of stone then yes, the sand will eventually compress into the gaps between the stones and your floor tiles will eventually settle over that and end up directly in contact with the stones. If you do 3" of stones, I'd do 4" of sand so that your floor tiles can't end up in contact with the stones.
You're going to end up with weeds no matter what you do unless you do a solid tile/grout or concrete floor. Even with a fabric barrier at any level, weed seeds will collect and sprout in the sand and any spilled media. Just plan on having to deal with them occasionally.

Why sand? It will impede drainage and be a good substrate for weeds to grow in.

Put in a thick layer of gravel, tamp it down and put the pavers directly on top.

Sand is for leveling, not so much for the drainage. I would layer big rock then a big layer of gravel then the pavers