How to Choose Patio Stones

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  • Transcript

    LESLIE: Creating a beautiful living space outdoors doesn’t require walls or a ceiling, just a beautiful floor. The perfect patio will complete your yard but the right choice of surface is key.

    TOM: Yes. And while most patios are made of concrete, stepping up to stone can really add a timeless look. Here to tell us more is This Old House landscaping expert Roger Cook.

    Welcome, Roger.

    ROGER: Hi, guys.

    TOM: Now, this is a project that I see people get wrong a lot. And generally, it’s because when they’re building that stone patio or paver patio, they don’t spend enough time getting the base right. Do you see the same thing?

    ROGER: It’s the same thing, boy. You’ve just got to do the base properly to make everything else look good.

    TOM: It’s kind of like the foundation for the patio.

    ROGER: Right. I think of it as a cake. The inside of a cake has to be good, too, not just the dressing on the outside.

    LESLIE: Yeah. But with a yard, you’ve got to go deep to get a good foundation. If you’re building a big patio, I mean this is a lot of work. And you’re going to encounter a whole bunch of things, like roots and plumbing and gas lines. This is a big undertaking.

    ROGER: It is. But it’s important to get it right. It all starts with the base. How are you going to feel when two, three, four years out, the whole patio is shifting and moving, you’ve got to lift it all up and redo it again? Sometimes, you can even hire a landscaper to come in, dig out the patio for you and do the prep and then you guys do the finish coat.

    TOM: So, if we are going to build the base, what’s the proper sort of assembly? What are the layers of that cake?

    ROGER: Usually, we want to dig down until we get down through to subsoil, which is below – what? It’s usually a loomy level of soil. That can be 6 to 8 inches deep. Sometimes, it goes deeper. We like that – to remove all that, save it, use it in another part of the garden, compact that subgrade. And on top of that, we try to put a mix of stone and stone dust we call “pack.” And we take that pack and we build it up and build it up. We put in layers compacted down either with a hand compacter or a gas-powered one until we get up to the finish coat. And usually the finish coat is like an inch or a stone or sand and then the paver itself on top of that.

    LESLIE: Alright. So now you’ve gone through the most labor-intensive part, you’ve got the base all prepped. What are some of our options to get that really beautiful patio? I’ve heard of something called the “Belgian block” but I don’t know that I’ve ever known this term.

    ROGER: Yeah. There’s a whole bunch of pieces you can add to the top once you’re ready. Belgian blocks are pieces of granite, which are hand-chiseled. They’re usually 6 to 8 inches wide, maybe 8 to 10 inches tall. And they can be set in. But the Belgian blocks aren’t flat and the patio isn’t flat. It’s really a rough surface. But it looks great with an older home.

    TOM: Now, what about bluestone? That’s a very common material for patios both old and new. Is that hard to work with?

    ROGER: No, it’s a great stone. It works really well. It comes in dimensional sizes so you can limit very much what you cut. But again, you get what you pay for. When you ask for bluestone, there’s a couple different colors with them. First, you order blue-blue, which is the most expensive you can get. And it’s true color or pretty true color all the way through. Then there’s random colored bluestone. And it has rust in it, it has purples, it has all sorts of colors. It doesn’t affect the bluestone itself but it just gives it a totally different look.

    I love that different change in color. I like it more than the blue-blue.

    LESLIE: Mm-hmm. Now what’s the difference between a bluestone and a flagstone? I’ve always sort of thought that term was interchangeable.

    ROGER: I’d say they’re both in the same family, with one being a stronger cousin than the other. The flagstone tends to really flake apart, especially when you use it set in a concrete base. It’ll get water inside and pop and just make the whole walk bad. Bluestone tends to resist that. It really doesn’t absorb water, so it doesn’t crack.

    TOM: Now, is flagstone similar to slate? Is it a type of slate?

    ROGER: Yes.

    TOM: Yeah. So I can – I know exactly what you mean. It tends to delaminate and sort of chip pieces away. And very often, we’ll see those flagstone patios where someone will put mortar in between. And that’s just a disaster waiting to happen, because there’s just no way that mortar’s going to stay in there once the patio starts to freeze.

    ROGER: We even repaired a walkway for Ask This Old House where the pieces were so loose that we took them out and we used the wall mortar – the tube mortar – and put it in there and pressed the piece back down in there and sealed it right back into place.

    TOM: There you go.

    LESLIE: What about paver bricks? I feel like – or “paver stones,” however you want to call them. I feel like those give you so many options. There’s different shapes, there’s different sizes and that’s almost like a puzzle.

    ROGER: Yeah, they do. They’ve come out with every color under the sun and every shape under the sun, too. So you can have a lot of fun with them but they still – even though they’re a blend, it’s not just one color. They’re usually a blend. It just doesn’t look as natural as bluestone or some of the other products do.

    TOM: Yeah. Well, it’s probably a more affordable option, right?

    ROGER: Yeah. It’s much more affordable and I think it’s pretty easy for anyone to put down once they get their base in place right.

    TOM: Now, speaking of paver bricks, once that project is done, they have to have – be filled with sand. The joints between have to be filled with sand. Is there a way to treat that sand so it’s not quite as absorbative (ph)?

    ROGER: Yes, nowadays we use a product called “polymeric sand.” And it gets swept in through the joints, you literally spray it down and it hardens up. And it keeps ants, weeds and even the water from going in between the pavers.

    TOM: And you’ve got to love that. Roger Cook, the landscaping contractor on TV’s This Old House, thank you so much for stopping by The Money Pit.

    ROGER: You’re welcome.

    LESLIE: Alright. Catch the current season of This Old House and Ask This Old House on PBS. For local listings and step-by-step videos of many common home improvement projects, visit

    TOM: And This Old House is brought to you on PBS by State Farm. Like a good neighbor, State Farm is there.

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