Patios – The Human Footprint

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.

A proper installation using Arizona flagstone with decomposed granite in between. You will rarely see it done properly like this.

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.

This Decomposed Granite with flagstone patio is not done correctly. Spaces are too big and will catch high heels and chairs

Indian pavers with decorative rock set on concrete base

Interesting walkway that incorporates brick, stone and boulders

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.

Two types of concrete are in this walkway

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.

Connecticut blue no joints — No joints in the perfect paver

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.

Decomposed Granite patio under willow. — **Decomposed Granite patio under willow**.

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!

Also Read:-

I’ve done 100’s of decomposed granite patios and walkways in northern California and learned a few things as I went along.

When I first began, the industry didn’t have a ‘hardener’ that you could add. That made for a semi-successful installation, because in the winter your walkway was mushy at best. With the advent of hardeners, the DG comes out quite nice, with minimal mush.

Get the DG pre-mixed with the hardener (some landscape outfits will deliver like this) or mix on your own in a wheelbarrow per the proportion instructions.

Prepare a bed that’s about 5″ deep. Use an attractive edging. I am totally committed to Ryerson header, which is a thin hard steel that’s bendable. That’s because it disappears. It is expensive though, comes in 16′ lengths with its own stake.

The other plastic headers are ugly. An alternative are the many colors and types of Trek, which is a recycled plastic material. Use the 1/2″ wide size. The advantage is that its more bendable than the steel, but it doesn’t disappear, so its part of your project design.

For complete instructions, advice, questions and answers, see my eBook on how to install decomposed pathways and patios.

How to Build a Decomposed Granite Patio

Lay down several inches of road base and use a compacter to compact it very hard and tight. Order enough DG to lay down 2″ on top, compacted. Then here’s the secret: apply the DG (with the hardener mixed in good) at the rate of 1/2″ at a time.

Then compact. If you apply too thickly, the stuff won’t harden well. The DG has to be moist when putting it down, but not sloppy. Compact 1/2″ at a time till you have your desired height. Sprinkle with water.

Another method I’ve used quite successfully was told to me by the contractor at Strybing Arboretum in San Francisco. All their paths are done this way, and they get tons of traffic.

For this method, DON’T use hardener. Apply a good road base foundation of several inches, maybe 3 or 4″. Then apply only 1/2″-3/4″ of compacted DG. Essentially this is a dusting.

You will have to reapply every few years depending on your traffic. I used this method for a patio over 4 years ago and still have not reapplied. I think this is a superior method because you completely eliminate any winter mushiness. Even with a hardener there will be some mushiness.

Some warnings: DO NOT try to apply a hardener after the fact. I once went to a potential job where the gardener had installed a walkway, then put the hardener in after he was done. Oh my God! What a mess. The whole thing had to be removed and redone.

Closeup of local fines and 3 Rivers Paver inserted for effect

Next warning:- Do not install DG directly next to an indoor situation. DG tracks. It’s granite and granite gets on your shoes and gets in the house. You need at least a few steps (not many) before you go inside.

My son’s elementary school built a new gym for millions of dollars. The landscape architect speced DG as the hardscape all around the gym. That was a disaster. All those kids tracked that DG into the new hardwood floor and ruined it! They finally installed concrete as a spacer.

Decomposed Granite grey — **Decomposed granite patios**

Next, the materials. Of course, every area is different. DG in the Bay Area came in gray, gold, or dirt brown. I’ve mixed them for different colors. Don’t be afraid to experiment a bit.

A new rock came out on the market from a local quarry that was cheaper (DG is expensive. Last I looked it was around $80/yard!). I was able to get ‘fines’ and used that successfully with the hardener for a coral color.

Anoter view of sunken DG patio — **Decomposed Granite patio with edging**

Decomposed granite ryerson header edging — Decomposed granite patio and ryerson header edging

For patios, (see my complete post on patios)I usually don’t like to have a visible drain, so I put the drain(s) on the outside in the shrub area. The exceptions are like the previous post with the photo of the sunken patio. Of course, I had no choice. But really, always remember your drainage.

One neat new alternative to DG is permeable concrete. Its more expensive than ordinary concrete, but it is nicer, much nicer, on the environment. Its fairly new and my understanding is that a good powerwash in the spring opens the pores and keeps it permeable.

If you found this short entry useful, but need more information, click on this link for my full downloadable eBook on patios and walkways, priced at only $2.99. I’ve collected hundreds of real-life questions from do-it-yourselfers and all those questions will be answered in this short pamphlet.

I’ve also included information on DG pricing, colors, how to customize colors, and drainage. If you are not sure if you should use DG or another material.

I discuss the advantages and disadvantages of concrete patios and their preparation, mortared flagstone, flagstone on sand vs. flagstone with DG, as well as how to prepare gravel paths and patios.

Chock full of information in just 46 pages with additional color photos. If you like the eBook, please comment in the Amazon section. I appreciate all my readers and thank you all very much.