In our article about the importance of concrete, it was highlighted that concrete is the most used material in the construction industry today. It’s overall durability, resistance to stress, and affordability made it a popular choice around the world. However, in recent years we have seen the emergence of concrete as an aesthetic material used to add flavor to projects spearheaded by architects.
Stamped concrete is one such method. This variation of concrete uses patterns, textures or embossing to resemble brick, slate, stone, tile, or even wood! Using stamped concrete to imitate other building materials, is a brilliant and cost reducing idea that enables builders to get all the aesthetic qualities of the imitated material, with the durability and resistance provided by the concrete.
But how do you make a quality stamped concrete? The stamping is worked directly on to the concrete before it sets, using prefabricated molds that contain chemical pigment releasing agents and sealants. Each mold fulfills its specific function within the stamping process and it is very important to apply them with the correct technique and the right tools. Here’s a quick guide on stamping your own concrete!
How to Stamp Concrete
Step 1: Preparation
Preparation of the base guarantees its uniform shape, and all of the above textures and patterns are made in the same way you would normal concrete. However, for this process very fine powder pigments will be used. It is best to protect adjacent areas using wind barriers, tarp and other coverings to avoid contact. Not only that but you as the applicator must be protected with gloves, masks, and eye protection as well.
Step 2: Concrete placement
The placement of concrete follows the same method as your traditional concrete flooring. Making sure to take into account any internal and/or external vibration, based on the thickness level you plan to use.
Step 3: Hardener Application
Generally, the placement of approximately 5Kg m2 of pigmented hardener is recommended, however, this may vary depending on the producer. Before applying the product, a visual inspection of the material must be carried out so that lumps are not present inside the product. These can cause bumps, lines or areas where the product is not wetted well. The hardener should be applied in light layers; It can be two or three to ensure that the product is properly embedded. When the concrete has finished exuding, the first layer is applied to try to cover 70 or 80% of the surface. This should be paved with a trowel made of Magnesium or wood.
Next, the second layer is implemented taking special care in places that do not have a hardener such as edges or dark areas, again flattening with a Magnesium or wood trowel.
Finally, if necessary, the third layer is applied. This is the layer you will want to apply the stamp over to but this time, because it is the last layer, you will pave it with a metal trowel to remove all types of marks that were left in the concrete previously. Under no circumstances should you apply water on the surface to help penetrate the hardener. This will cause stains, hardener detachment, and possible detachments.
Step 4: Release agent
The release agent allows in addition to providing longer working time for stamping with the molds, to have a secondary color to better notice the indentations, such as details and joints of the molds. After applying the release agent, you will be done using a trowel.
Step 5: Stamping
Now, before starting to stamp, make sure your team knows the molds, their shape, sizes, direction of placement, and start and end of stamping. A test section, on concrete or sand beds, is encouraged to ensure that everyone knows how the work should be done and to practice the placement of the molds.
Stamping kits typically include three types of molds. The first one is a textured skin to allow stamping on edges and hard-to-reach areas where rigid molds fail to give texture.
The second one is a platform mold, much thicker and stiffer than the previous ones. These allow walking on them without causing damage to the concrete to stamp the rest of the concrete.
Lastly, the third mold is a flexible platform for stamping in hard to reach areas.
Stamped concrete is a process that requires a lot of meticulous work but the details are important to provide an impeccable design. Stamping concrete is not an easy feat so if you’re looking to have stamped concrete for your next project we highly recommend to contact a local expert. If you’re not from the midwest, and have questions on how to vet your contractors we’re always happy to help – give us a call at 708-789-9693!