Mirrored glass has been a popular terrazzo aggregate for many years as it added a beautiful sparkle and depth to the terrazzo.
There are several different mirror aggregates available. The 4 basic types are:
One Side Mirror
Double Sided Mirror
All Sided Mirror
Coated Mirror
Each has advantages and disadvantages as well as different pricing.
Below is a side by side comparison of the different types. Each sample was cast using 30% mirror glass. From right to left: Silver Coated, All Sided, Double Sided, ASG One Side, SM One Side, UC One Side.
Let’s look at the most common first:
One Sided Mirror
There are several supply sources for one sided mirror. Most are from discarded wall mirrors some from women’s makeup compacts. Good news is all this mirror is post-consumer recycled. However, it’s not all the same quality or purity. One side mirror is just that, it only has mirror backing on one side of the aggregate. Thus, depending on which side of the aggregate lands facing up there may or may not be the reflective quality you are looking for. That being said, if you are looking to get 10% reflective mirror content you will actually need to specify 20-30% depending on the quality of mirror. One side mirror is the least expensive option for a mirror terrazzo aggregate.
Let’s review the sources:
My favorite One Side Mirror is from ASG. It has a thick mirror backing so there is minimal loss of mirror during processing and crushing. However, this comes at a cost. This mirror aggregate is twice the cost of the other options, but the net result of mirror reflectivity you get really ends up being the same because you can use a lower percentage of the mix. If the heavy backing lands face up, it is black in color so you can expect some percentage of black when you use this chip. 10% of this mirror adds approx $.60 per sf in material cost. Unfortunately, we were recently informed that this mirror is no longer available.
SM One Sided Mirror is a good quality and bang for your buck. The mirror backing is pretty good quality. During processing it still loses more than the ASG mirror. However, it's half the cost. This is a post consumer product so you can get some rouge chips of different colors but in my experience it's been a very pure source. 10% of this mirror costs approx $.30 per sf in material cost.
UC One Sided Mirror is my least favorite as the mirror backing is fairly light and much of it is lost during processing. Furthermore, it typically contains rouge colors often ash gray, blue or sea green colors. Its offered at the same price as SM One Sided Mirror so this is not my preferred source.
Double Sided Mirror
This source contains mirror backing on both sides, sourced from the two way mirrors. This is a premium product and for the price I just don’t think it's worth it. As you see from our mirror experiment, the lesser expensive ASG mirror actually provided more reflectivity at the same percentage. 10% of this mirror costs approx $1.60 per sf in material cost.
All Sided Mirror
This mirror aggregate contains mirror backing on all sides. The idea being you are guaranteed reflectivity no matter which way the aggregate faces. Almost appears like a diamond in the floor. Again this is a premium mirror but you get your money’s worth. A small percentage (5-10%) goes a long way. 10% of this mirror costs approx $3.00 per sf in material cost.
Coated Mirror
This mirror is similar to all sided mirror as it is coated on all sides. However, it can be coated in different colors aside from silver, such as copper or gold and even other colors. This is the most expensive mirror and will carry a premium of $5.00 per sf for every 10% used.
The verdict:
SM One Sided Mirror is your best bet if you are looking for something recycled, affordable and that gives you a reflective pop. My next choice would be the All Sided Mirror if you prefer that look. Lastly the coated mirror is a good option if you are looking for something really unique and have a healthy budget. We hope this post has been helpful. As always, feel free to reach out if we can answer any questions or provide any samples. Thanks for reading.
Below are some projects featuring different mirror types: