Mansonary advice needed

[Egon]

Commercial pavers may not use stone.

Mix the two sand sizes to get better density and use more Portland to allow for the gap grading.

 

[GLyford]

Crusher fines are bigger and coarser than sand, and will lock better for more strength. I'd go with crusher fines, with or without sand before I would go with just sand.

On my form pavers, which used 1/2" stone and crusher fines (should have used graduated size gravel and sand), there are places where the water sits and freezes where they are already coming apart. In place still, and still OK for putting patio furniture on, but when the ground is saturated you can feel the pieces move when you walk on them. If you want it to last, straying from the "best practices" mix is not the way to go.

Have you priced out getting a slab poured? Framing one up isn't that hard, and if you don't mind a broom surface not too hard to finish. Hardest part is shoveling the mix around and screeding off. Hire a finisher and even that isn't too bad. And you could use real rebar, or put your wire on chairs if you want. Or not put in any metal at all, as long as you keep remembering it is a patio and not try to park cars on it.

 

[GLyford]

Pavers on top of a slab is the best way to do them, most people don't bother because you are paying for both pavers and a slab. But to dress up an existing slab, I say sure. Top dress and screed with a little sand to bed the pavers in (I would have to look up the recommended depth, but I suspect 1/2" would be fine) and go wild.

 

[muddstopper]

Heres what I am thinking for a mix. 2 portland, 2 sand, 3 rock fines. Anybody think that will hold up and not crumble if laid on top of concrete slab with vehicle parking.

 

[Egon]

With the right amount of Portland cement it'll do just fine.

You don't have to worry about the aggravate locking together. The cement makes the glue that binds it together.

The object is to get the fines and sand mixed to maximum density to reduce void space. This saves cement as it must fill the voids.

 

[muddstopper]

Mixing wont be a problem, I have a mixer

 

[forgeblast]

I did a lot of casting from the forms for borders and for pavers. The main thing I saw or had happen was the form failed after a bit. If its the cheaper plastic forms, tape it in duct tape, and put it on a piece of plywood so that your not using the form to flip the cured paver. You can spray the forms too with spray veggy oil to help with the release. If its on plywood too you can hit the plywood to get the air bubbles out of the surface.

 

[DaveK OR]

To keep the weeds from growing up, add a good pre-emergent herbicide to your spray mix. Be careful with which you choose, because some of them will stain stain concrete.

Roundup has an off-the-shelf mix that includes a pretty good pre-emergent, and with that it should stay weed-free for 3-4 months at a time.

Another alternative is to sweep some Casseron or similar soil sterilant into the cracks and spaces between pavers.