Find out the proper way to build a walkway so it doesn't break apart when the soil freezes. Get tips on how deep to dig and how to pick the appropriate material for your climate.
LESLIE: Well, if you’re thinking of installing a new walkway, there are things to consider beyond the prettiest materials, especially if you live in a climate where frost is a problem.
TOM: That’s right. And when soil freezes, it expands and it can lift and even break apart walkways, patios, sidewalks or driveways. But that won’t happen if it’s built right. Landscaping contractor, Roger Cook , from TV’s This Old House  is here to tell us how.
ROGER: Thanks for having me.
TOM: Now, when we build a foundation, we’re accustomed to digging down below that frost line to make sure the foundation won’t move. But with a walkway, it’s not always possible to dig down that deep, nor would you want to. How do we keep that from moving?
ROGER: Well, whenever I build a walkway or a driveway or any sort of paving area, I like to go down a foot. I take out 12 inches of material. Usually, you get topsoil in the top 6 to 8 inches but I want to go down and make sure I’m below that topsoil level. Usually, the topsoil is brown and it holds moisture.
TOM: Draining is really the key here.
ROGER: Right. That moisture is what’s going to freeze and expand and move your walkway. So we dig down a foot. We usually put in what’s called “pack.” And pack is a combination of stone dust and ¾-inch stone. And we bring that up in 3-inch lifts. In other words, we put down 3 inches; then we take a compactor, pack it down and keep working our way up.
The great thing about pack is it packs up hard, where it’s a good, great base for the walkway but it drains; it lets that water get out from underneath the walkway.
LESLIE: Now, I know a lot of people talk about – when we’re discussing base prep, they talk about the frost line. You want to be below the frost line. How do you know where the frost line is? Is that a visual cue? Is it something you know by region or like you mention, is it just “OK, I’ve seen the change in the soil and now I’m good”?
ROGER: Below the frost line only pertains to concrete walls and footings for your house. No one is going to dig down here in New England 4 feet deep for a walkway to get below the frost line, OK?
ROGER: So that’s where picking the material comes into place in how you put the walkway in. I like to do walkways and patios dry, which means there’s no mortar and no cement involved there, set on the pack on an inch of stone dust and then the final top piece is put in.
If you look – put in a concrete walkway, it doesn’t – it can’t move. It structurally – it cracks. Pavers can move but they’re set in stone dust and if worse comes to worse they do move too much, you can reset them again by just scraping out a little stone dust and putting it back. You can’t do that with a concrete walkway.
TOM: So does that make pavers  a much better choice for a harsh climate than – compared to, say, concrete?
ROGER: It does in my mind. Up here in New England, concrete is bound to fail sooner or later. In warmer climates, it’s a perfect solution: it’s very efficient to go down, cost effective and will last forever in areas like Florida.
TOM: Now, what about sealers once the project is done? Do you think it’s a good idea to put some sort of a sealer on a paver? Does that actually help slow down the absorption of water or does it let the water in and trap it?
ROGER: No, it definitely helps keep water from getting in. But what I tell everyone is to take a couple of bricks, seal them first and see if you like the look. Because it’s a total different look; it tends to be like the pavers are wet or shiny, so …
LESLIE: Oh, it gives it almost a gloss.
ROGER: Right. So make sure you look at some before you do the whole walkway and then decide you don’t like the look.
And there is a reapplication thing; it doesn’t – it isn’t one application that lasts forever.
TOM: So there is some maintenance involved; it has to be repeated from time to time.
ROGER: Right, exactly.
TOM: Good advice. Roger Cook from TV’s This Old House. He’s a guy that knows how to build it once, build it right so you really don’t have to build it over and over and over again.
Thanks so much for stopping by The Money Pit.
ROGER: It’s my pleasure.
LESLIE: Alright. You can catch the current season of This Old House and Ask This Old House on PBS. For your local listings, visit ThisOldHouse.com.
TOM: And This Old House is brought to you by Lumber Liquidators. Lumber Liquidators, hardwood floors for less.