Frequently Asked Questions

What colors are available?


Any color! Concrete can be made in hundreds of colors including every color on the spectrum. Any color can be produced in a solid, speckled or variegated pattern. And, you can specify embedded stone, glass, or other objects. You can specify the color, size and density of embedments. Coupled with the many color choices, you have myriad design options.

How much color variant can occur?

  

Concrete is a natural, handmade material. Many factors such as humidity, sand lot and cement lot can affect the final appearance of the concrete. All of our color formulas record the type of sand, type of cement, and exact measurements of pigments to 1/10th of a gram, and we use specially developed software to calculate mix design. However, colors can still vary because of the aforementioned factors.

  

Another factor that contributes to perceived variation is simply the size of samples. A 6” x 6” sample will look different than a whole countertop simply because the small sample does not capture all of the natural, random variations that will occur over a large surface. The color in a 6” x 6” sample may appear completely uniform, but a whole countertop in that exact same color will not appear as uniform. The same situation occurs with other natural materials such as granite. If you are looking for perfect uniformity, you might not be right for concrete, and you should choose solid surface instead.

What edges are available?

  

For concrete, edging is formed and cast rather than cut like granite or solid surface. Therefore, edge choices depend on the availability of appropriate trim molding. For example, Rockface Concrete Artisans can do pencil, beveled, concave, bullnose and reverse cove edging, and other custom edges may be available. Edging may be placed on top or bottom of the countertop. 

What kind of sink can be used?

  

Rockface Concrete Artisans countertops can accommodate all types of sinks including drop-in, undermount and apron front. 

The minimum lip of concrete around all sides of sinks is 3”. Concrete can also accommodate drop-in cooktops. The minimum lip of concrete in the front of a cooktop is 3”. We recommend 3” for the back also, but 2” will suffice.

Rockface Concrete Artisans can make integral concrete sinks of almost any shape. Bathroom vanity tops are an excellent application of integral concrete sinks. 

We do not recommend integral concrete kitchen sinks for engineering reasons. Kitchen sinks are deep and have angles that would put large stresses on the concrete and have high potential for cracking. Also, the size of kitchen sinks generally dictates a very thick concrete bottom that would be a problem with standard plumbing and cabinetry.

Concrete vessel sinks are also possible, and concrete’s versatility means that the sink can be any color and shape.

Will they sratch?

  

While the sealer is durable, it can scratch if cut with a knife or subjected to heavy, sharp objects dragged across the surface. Cutting on the concrete may compromise the integrity of the sealer and allow stains to permeate the concrete matrix. Cutting on the concrete will also ruin knives, requiring a professional resharpening to reshape the damaged edge. Remember, concrete is made with stone, the same thing used to sharpen knives (and will therefore dull them just as easily). If you do scratch a countertop, you can easily repair it yourself using your Touch-Up Kit. 

Will concrete countertops stain?

    

Bare concrete is very porous and will readily stain. Virtually all concrete kitchen countertops are sealed to prevent staining; however, the degree to which these sealers work varies significantly. Commonly used sealers include wax and penetrating acrylic sealer. Both of these are inexpensive and easy to apply. However, neither offer significant stain or heat resistance, and both require frequent reapplication to prevent the formation of a “patina”.

Rockface Concrete Artisans’ sealer is different. We use a high-performance sealer that is exceptionally durable and provides excellent resistance to incidental contact with staining agents such as red wine, lemon juice and olive oil. Complete care instructions are included in your Owner’s Guide. Touch-up of any marks that do occur is simple and easy.

Can I put hot pots on the countertops?

  

As with almost all types of countertop surfaces, it is best to use trivets. Concrete can microcrack if exposed to high heat, and the sealer is not elastic enough to “absorb” these microcracks. The surface will appear “crazed”. However, the Touch-Up Kit can be used to minimize the appearance of these microcracks, just like it is used to touch up scratches.

What is the lead time?

  

Although countertops are one of the last items to be installed, concrete countertops should be selected as early as possible. Here is an outline of the process:


1. Color selection

-Rockface Concrete Artisans often performs custom color matching and submits samples for your approval. Allow about 3 weeks for this process. See the section on custom colors for more information.


2. Templating

-Templating is done from finished and installed cabinetry, and it takes less than one day.


3. Fabrication

-The typical time required to fabricate most concrete countertops, depending on their size and complexity, is 3-4 weeks. Note that the fabrication process may not start immediately after templating depending on how full our production schedule is. A good guideline is to contact Rockface Concrete Artisans at the beginning of the project, or at the latest one month before cabinetry is scheduled to be installed, both to allow time for custom color samples and to secure a spot on Rockface Concrete Artisans’ production schedule.


-In the case of a residential project such as a complete kitchen remodel, homeowners are usually willing to wait longer for their custom-made, handcrafted concrete countertops. However, temporary countertops can be a way to minimize inconvenience. Temporary plywood countertops are one possible solution. Or, the contractor can preserve parts of the old countertops to provide some work surfaces. 


4. Installation

-Because Rockface Concrete Artisans’ countertops are precast and prefinished, installation generally takes less than one day.

How are templates made?

  

Concrete countertops are templated just like quartz and granite. Templating is done after any existing countertops are removed, or after new cabinets are fully installed. Your contractor needs to arrange for existing countertops removal. Almost all concrete countertops require physical templates from the finished and installed cabinetry. 

In some cases, such as small or freestanding pieces, we can fabricate from CADD drawings instead of physical templates. We will advise on templating requirements for your project, and we provide your contractor with a templating checklist to help him prepare. All fixtures that penetrate the concrete, such as sinks and faucets, must be available at templating time.

How are they installed?

  

Concrete countertops are handled and installed just like quartz and granite. Seams are caulked with a color-matched acrylic caulk. Your contractor needs to arrange for plumbing and electrical hookup no earlier than 24 hours after the countertops installation.

Are there any seams?

  

Often concrete countertops can be designed without seams. Seams may be located around sinks and cooktops, or wherever required for structural reasons. Or, seams may be necessary due to the logistics of getting the slabs into the house if stairs or corners are involved. Rockface Concrete Artisans will work with you to design seam placement that is both structurally sound and aesthetically pleasing. 

Seams are typically 1/16” wide, similar to tile grout lines. However, it is important to realize that concrete countertops are handmade and hand processed; they are not machine cut, so tolerances for seams are more generous than with quartz or granite. Seam appearance is minimized by using color-matched acrylic caulk.

Are there any special structural considerations?

  

No. Standard precast concrete weighs about the same as quartz or granite of the same thickness., and glass fiber reinforced concrete weighs half as much. Typically, no special considerations are necessary for standard kitchen or bathroom vanity tops. Cantilevered slabs, bartops on kneewalls and similar situations sometimes require brackets or other structural supports. Rockface Concrete Artisans can advise on support requirements.