What you need to know before installing a stamped concrete patio

October 3, 2014

It wasn’t long ago that I wrote a blog about patio material options. One of those options was concrete. Concrete comes in many forms but seemingly the most popular is stamped concrete. Not to scare anyone away or divert business from the many talented concrete contractors but there are many variables when it comes to concrete.

The best way I’ve ever heard it explained came straight from a concrete contractor… (Paraphrased, of course) Concrete is a crude material that we try to control to look refined. There is nothing refined or elegant about the creation or installation of concrete but when everything goes perfectly the finished product can be beautiful.

As a designer, concrete is an appealing material because it can take so many shapes, colors, and styles.

To achieve a more modern look we have used a sand finish concrete with no color additives and a simple joint pattern, like in the photo below.

 Sand finish natural concrete. Medina, WA - Sublime Garden Design

Sand finish natural concrete. Medina, WA – Sublime Garden Design

 

For a craftsman vibe it can be dressed up with stone.

 

Sammamsih, WA Stamped concrete with stone border

Sammamsih, WA Stamped concrete with stone border- Sublime Garden Design

 

Or for a country farmhouse it can be simplified and become a quaint patio space.

 

Stanwood, WA Stamped concrete patio

Stanwood, WA Stamped concrete patio – Sublime Garden Design

 

There is a color and stamp to fit almost any style. We make everything from patios, to walls, to water features using concrete to achieve the look we desire.

 

Issaquah, WA Stamped concrete patio

Issaquah, WA Stamped concrete patio- Sublime Garden Design

 

That all sounds great, right?

Concrete cracks. No matter what, concrete will crack.  It can happen days after a pour or years later, but it will happen. We try to control where it cracks by creating control joints (hence the name). A control joint basically creates a weak spot in the concrete which the concrete will hopefully take advantage of and crack there instead of somewhere else.  But concrete, just like the weather, doesn’t always do what we want.

Speaking of the weather…

Stamped Concrete is insanely weather dependent! If there is any chance of rain the contractor will not pour, finish, or seal concrete. If the weatherman is wrong and it does rain it can be very detrimental. Too much water can affect the color, consistency, texture, and even the time it takes to cure. The temperature outside also has a great effect on concrete. If it is too cold the concrete will take longer to harden. On the flip side, if it is too hot the concrete will harden too fast which can greatly shorten the time the contractor has to apply colors and stamps.  Curing too slow or too fast can both decrease the structural quality of the concrete.

Everything about concrete is variable.

The mix is never exactly the same, the color is never exactly the same, and none of it is entirely controllable. We can select the same color and stamp for two different patios and they will look entirely different.  There are additives in the concrete that are different based on the supplier of the concrete and also by the day of the mix. The exact amount of color that is added or how it is added is never exactly the same. There are also colors that have a greater tendency to look better (browns and grays) and those (terracotta) that will take on a pinkish tinge and (in our opinion) consistently look bad. We are brutally honest with our clients when selecting concrete colors if they are leaning towards one of the troublemaker colors.

Color

In addition to the various finishes, colors, and stamps there are different ways to create color. There is integral color, applied color, and acid washes/stains.

Integral color concrete has the base color of the concrete mixed in while it is in the truck. It can then also have a sprayed on release color applied during stamping to give a two-toned effect.

With applied color concrete the color is applied in powder form after it is poured and before the stamp.

Acid washes or acid stains use various different chemicals to create a chemical reaction with the components of the concrete to create different colors.

We do our best to educate our clients ahead of time about the problems that can occur not only with concrete but with the entire construction process. But it is human nature, no matter how many times you tell someone that the concrete will crack, the color won’t be exactly what you picked out, or the many other variables involved; it will still be disappointing when it happens. Much like a car accident, you never think it will happen to you.

We recently had a concrete pour that didn’t go as planned. We always have anxiety on a concrete day but when I looked out my window in the morning and saw blue sky and sunshine I was able to breathe a little easier. About half way to the client’s house the sky darkened and my stomach sank as I watched the rain hit the windshield. When I got to the job-site it was only sprinkling, but that is still not good.

Bothell, WA Stamped concrete before

Bothell, WA Stamped concrete before

Long story short, the extra moisture made the release color (the dark color that is put on top) pool as it dried and it didn’t look right. A few days later once cleaned and sealed the concrete looked like cheetah print. Not the look we were going for.

The good news was the base color and the stamping and finish work of the concrete were good, the only problem was the release color. So we formulated a plan to acid wash the patio to strip some of the release color off (after stripping the sealer as well).

Bothell, WA Stamped concrete after acid washing

Bothell, WA Stamped concrete after acid washing

Although a little un-nerving to watch the acid foam and bubble on top of brand new concrete, it made a huge difference. It was quite the process of scrubbing and washing but well worth it. After all the goal of everything we do is to make a beautiful space that the client loves.

We will have photos of the finished project soon. Tell us what you think of stamped concrete and your experiences with it.

~Kryssie

 

2 comments... (add a comment)

  1. I never knew that the temperature is really important in stamping concrete. As you said, a cold weather will lengthen the time of the process while a hot weather can make it fast. I guess I have to wait until the sun comes out before I hire installers so that the process will not take too long since we won’t be able to have extra money for their extended service. We just wanted our patio to look great because we plan to have barbecue evenings outside during weekends.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.