Coloring your Stones

Cement comes in gray or white.  You will need to add pigments or admixtures to your concrete mix  to create a color scheme beyond just gray or white. There are many ways to color concrete.  Some techniques require lots of time and effort. Other techniques require minimal effort beyond making a concrete mix.

Below are standard techniques that can be done by anyone who can make a concrete mix

Integral Coloring:

Adding pigments to the concrete mix will create integral color that saturates the entire stone. The process of creating integral colors in concrete is as easy as tossing a bag of pigment into your concrete mix and mixing it in.

Basic Items Needed to Make Stone Veneer

    A level Surface to place the molds.

• Concrete Iron Oxide Pigments such as Davis Colors.
  

• Concrete Mixer or by hand for smaller batches.
  

• Concrete Mix (Lowe's or Home Depot)
  

• Make sure the area is well ventilated.
  

• Wear goggles, long sleeves and long rubber gloves.
  

• An apron will save you from wasting a lot of clothes.
  

• A cloth face mask.
  

How Much Pigment To add With integral Colors:

Pigment should never be more than 10% of the cement added to the mix. The color of freshly cast stones will lighten roughly 30-50%.

Adding Accent colors on top of integral coloring:

Accent colors can be achieved using various methods, we are going to focus on the two of the most popular techniques.

Technique One:

Take the bag of iron oxide pigment and use a sponge brush to apply dry pigments to the surface of the molds (a sponge brush will leave less excess pigment behind than other paint brushes). Adding too much dry pigment to the surface of the molds will actually make your stone veneer bleed when hit with a water source.

Technique Two:

Make a concrete mix for each accent color.  Apply a thin layer of the wet concrete mix, by hand or brush (not a sponge brush), to the surface of the molds.  Pour your based color on top of the accent color and wait until the stones are ready to be pulled...that's it.

Trouble Shooting

You shouldn't get into too much trouble when making stone veneer if you follow the instructions above  If you do have trouble you will more than likely have it with air-bubbles in your stones.  Just remember that air-bubbles are going to happen in every batch, the key is to minimize them.  Even the largest manufacturers have air-bubbles.

Here are a few reasons air-bubbles happen:

• Not enough vibrating or shaking of the molds after pouring in concrete.
  

• Small holes in your molds are producing air-bubbles.
  

Brittle Stones:

• Concrete mixing ratios are incorrect.
  

• The water is evaporating from the stone veneer too soon.  This can happen if the stone veneer is getting too much direct sunlight within the first few days of curing.  This can also happen if the temperature is too high in your stone veneer curing area.  A simple method to prevent brittle stones due to water evaporation is to cover the stones with plastic or cardboard for the first few days.  You can also spray water on the stones to rehydrate the concrete during the curing phase.
  

BASIC CONCRETE IS A MIXTURE OF:

1. Cement

2. Coarse Aggregate (rock) ( prefer lightweight)

3. Fine Aggregate (sand)

4. Water

Copyright DiYStoneVeneer.com 2010

Excessive direct skin exposure to cement/lime will eat away at your skin and cause excessive dryness as well as constant burning in exposed cuts.  Vinegar will neutralize the cement/lime on your skin.  Keep a bottle handy and always use it at the end of the day.

Basic Steps for making stone veneer

Step 1:  Decide on your color scheme and make a concrete mix or mixes to fit your color scheme.

Step 2: Slowly pour your concrete mix into the molds. You do not have to fill the molds all the way to the top.  Shake or vibrate the molds to level out the mix and to release air-bubbles.

Step 3:   Wait 8-12 hours at a temperature of 70+degrees (Lower temps require longer setting times, refer to concrete 101 for proper curing temperatures) then carefully pull your stones out of the molds.

Repeat Steps 1 - 3 until you reach your desired amount of stones.

The aggregate comprises from 60% to 75% of a concrete mixture, and cement paste (the combination of cement, water, and possibly flyash) makes up the difference.  Use a Type II/V Portland Cement; Type II cement is rated as "Moderate Sulfate Resisting” and Type V cement is rated as "High Sulfate Resisting".  Below, you will find information defining the types of Portland Cement.  Potable water, which can be provided at 35 degrees Fahrenheit in the summer, or 140 degrees Fahrenheit in the winter.

WATER-CEMENT RATIO

The Water-Cement Ratio of a concrete mixture is critical to its overall quality.  Generally, a lower water-cement ratio allows for increased compressive and flexural strength, a better bonding concrete, reduced shrinkage cracking, lower permeability, and a better resistance to wear and weather.  In other words, the less water the better!

DETERMINING THE WATER/CEMENT RATIO

The water-cement ratio is determined simply by dividing the weight of the water in a cubic yard of the mix by the weight of the cement.  The ratio will generally range from .35 to .70, and over .70 in grout mixtures.  Water-cement ratio can also be determined by testing a hardened sample of the concrete in an ASTM testing laboratory.

Do it Yourself Stone Veneer How To Page