It’s funny- for the longest time, I would have said no. Emphatically, in fact. After all, there have always been several flaws with stamped concrete, many of which are still a negative:
- Difficult to change- once a slab is poured, that’s what you have. To reduce it for any reason, you would need to saw cut and remove a portion. To add on to it you can pour a new pad, but good luck getting the colors to match. Pavers, brick, and stone are a little easier to change out depending on how they were installed.
- Life span- Concrete doesn’t last forever. If you get a section that chips, cracks, spalls, or stains, you have the same problem previously mentioned that it’s difficult to patch unobtrusively.
- Cracking- this is a big one. Concrete WILL crack; anyone who tells you otherwise is full of it. The reason is that concrete is strong in compression, but not tension. What does that mean? Imagine that a piece of styrofoam is a concrete slab. If we load it so that the forces are pushing down on the slab evenly, it handles it. Now, let’s put the styrofoam on the edge of the table and put a weight on the end hanging out into space. It fails, because it is weak in tensile strength- just like concrete. This is why we put steel reinforcing rods (rebar) in concrete. We’re taking a product (steel) that has high tensile strength and giving some of that to the concrete. However, even reinforced concrete will still exhibit surface cracking.
- Expansion joints- this is my pet peeve. I’ve seen too many artfully done stamped concrete slabs where the contractor does a pretty convincing job of an irregular stone pattern, then strikes a joint right through the middle of it, ruining the illusion. To avoid this you need to find a good contractor AND let him know you don’t want to see this.
- Surface finish- too many slabs are sealed with a glossy, fake-looking sealer. Also, sealed concrete can get slippery underfoot. There are sealers out there that have less of a sheen to them, and there are also additives that will make them less slippery (“up the coefficient of friction” if you want to geek out)
So Dave, you say, why on Earth would you let anyone use stamped concrete? Don’t get me wrong, I will almost always design with the idea of using brick or stone first. It comes down to a budget issue. In northern Virginia, the cost of stamped concrete is usually right around $15 per square foot, essentially half the cost of wet-laid stone or brick. That’s pretty huge. If it’s a pattern that translates well to stamped concrete I would rather see the project move forward than have the client take the plans, roll them up, and put them in the closet for a decade. Where’s the fun in that?
This project actually worked remarkably well with stamped concrete. It was designed to be 2’x2′ flagstone squares, laid in a grid pattern on concrete. Instead, we used a stamp pattern that makes the slab look like one big piece of stone and used a masonry saw to cut grid lines in the concrete. Even with natural stone used for the wall and firepit, the concrete still looks good. Apologies for the picture of an unfinished site, but we’re still working on this one.
So to answer the original question of the post, is stamped concrete any good? It certainly can be, with the right design and the right contractor. Make sure you have both of those in place and you can get a great finished landscape.
UPDATE: Here’s a pretty cool little set of steps one of our stamped concrete contractors did in northern Virginia.