I received a question from someone on using concrete pads underneath a DG patio, instead of prepping the subsurface with baserock material. That got me thinking about doing a post on patios in general and what, from a designer and installers perspective I know and understand.
First a few words in general regarding different types of patios. There are lots of different materials out there, some nice, some not, that can be used, and of course, different areas of the country will have different requirements. As far as drier climates goes, here are the basics:
1. Use materials like DG (decomposed granite) or concrete pavers (set in sand) when you need a permeable surface. Many counties are now requiring with new installations a minimum of permeable surfaces to prevent massive run-off problems. DG is useful as a patio some distance from the house in order to wipe off small bits of granite attached to shoes. Concrete pavers are set on a sand base and come in all types, from ugly to handsome.
2. For leisure patios with furniture lots of do-it-yourselfers or people on tight budgets like to put pavers and DG together. This works fine but keep in mind that high heels and furniture will get caught in the cracks of DG. There are ways to minimize this. Refer to my DG Patio book for spacing on pavers and proper installation. You will have to convince your contractor to use my methods because it is more time intensive, but it works.
3. For a long lasting patio that will have furniture on it, I prefer to pour a concrete base and put mortared pavers on. Another alternative is concrete. There have been lots of advances in concrete in the past few years. Meaning there are lots of types of decorative concrete looks, with stains and stamps and 2 or 3 dust on colors; finishes with broom, or salt pitting, or hard trowel. Just keep in mind that concrete is not a controllable substance and colors vary, fade, and cracks will develop no matter what.
A WORD ABOUT PAVERS: If you decide to go for real stone pavers, I salute you. Although concrete is cheaper, stone is beautiful and will give you lasting pleasure. So how do you choose amongst all the choices at the yard. First, go to a large landscape supply yard and pick out the stones you like. Get samples and bring them home and live with the samples for a week or more.
You must map out your design exactly. Usually the stone yard will have some basic design patterns for you to work with, or simply obtain some grid paper and go to work. Indian pavers have flooded the market in recent times. There are some incredibly beautiful stone and colors amongst the choices, but the stones are not all exactly to size. You’ll have to work with this when you or your contractor lays it down, which means some of the spacing will be off.
Next you must decide on the size of your joints. Be exact in your communications to your contractor. If you have uniform stone, you can lay them down with no mortar in between. If you want joints, or if your stone isn’t perfect as in the Indian pavers pictured below, you must have mortar showing in the joints.
As far as flagstones go, there are many types, some of which I do NOT recommend because you will develop moss in the wet season and you MUST seal these types every year to prevent mold. I discuss this more in depth in my eBook.
In general choose flagstones that are hard with small pores. These would be stones that come from places like Montana. Flagstones come in many names, and what’s called one name in one yard will be named something else in another, even if its the same material. Just make sure the flagstone is dense.
Another thing you want to watch for in flagstone is how slick it is. Slate, though gorgeous, is really slippery when wet. I’ve heard that a little bit of sand in your sealer can help this problem. Better to avoid it from the start.
For a more in-depth discussion on these topics, see my DG patio book. In it I discuss all the pros and cons of different materials, as well as give exact instructions for the installation of the different mediums, whether your contractor installs it or you do. I’ve tried to keep the price to a bare minimum and it includes all the tips I’ve learned from years of experience. Good luck and do it right from the beginning. Hardscape, unlike plant material, cannot be picked up and moved, and is expensive!