Marble vs Concrete Countertops | Everything you need to know!

April 13, 2022

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In this article, we will delve into the key aspects of marble and concrete countertops, comparing their physical characteristics, manufacturing methods, costs, and environmental impact. Learn all you need to know to make an informed decision when selecting the ideal countertop for your home.

Marble Countertops

Marble, a metamorphic rock formed from fossilized marine organisms, offers a beautiful and unique appearance.

Pure marble is a bright white rock composed of an interlocking mosaic of carbonate crystals. The presence of mineral impurities can cause it to change color and create characteristic swirls and veins.
For example, iron and feldspar will turn marble pink. Iron oxides will cause yellow and brown deposits. Serpentine will create a green hue. Porphyry will create violet coloring. Graphite will turn marble dark and gleaming like gunmetal.
Marble is found in many places. Italy, Spain, Brazil, China, India, Portugal and Turkey are among the world’s top producers of marble, with each country quarrying more than one million tons each year.
Large blocks of marble are cut out of the earth and transported to a factory. They are covered with a fiber mesh and glue to strengthen the block and make it safer for cutting. The block is cut with a gangsaw machine into thinner slabs. Then they are polished with large industrial sanders. Straight cuts are made with a wet saw. Irregular shapes and curves are cut with a water-jet.

Since marble is 100% natural stone, every slab is different. Its patterns and veining look soft and organic, unlike engineered quartz which can sometimes look fake. Marble has been used to make sculptures since ancient times because it is relatively easy to chisel and because of its sub surface scattering properties.

Concrete Countertops

Limestone, sand and clay are quarried and crushed into small rocks. It is combined with iron ore and fly ash. The ingredients are the source of calcium, silica, alumina and iron. As they are ground, mixed and fed into a steel rotary kiln, certain elements are driven off in the form of gasses. The remaining elements unite to form a new substance called clinker. Clinker is then cooled and pulverized into a fine powder and mixed with gypsum and limestone. The result is Portland Cement.
Concrete countertops are made with a mortar mix consisting of one part cement and three parts sand.
Once the mortar mix has cured, the countertop is polished to remove the rough finish and add an attractive sheen.

Concrete can be colored in four different ways. Pigments are added to the wet mix so that the color goes all the way through. Stains can be used on new and existing concrete. Color hardeners strengthen and add intense color to the surface of concrete.

Comparisons

Physical Properties: Marble countertops are thinner, around 3 cm or one and a quarter inches. A standard 1.5” thick concrete countertop weighs approximately 23 lbs per sqft.
Appearance: Marble countertops are usually lighter colored and are perceived to be higher quality and add more value to a home. Concrete countertops are usually a darker gray color and have a rough, industrial appearance.
Porosity: Marble is a porous surface, which makes it highly susceptible to stains. It requires frequent resealing every 6 months. Concrete can be used in kitchens, but be aware that it is not a pristine looking surface. It will change color, get scratched and stained and will patina over time.
Finishes: Marble countertops can be honed, leathered or polished which adds a gloss sheen to the surface. Concrete countertops can have a low-luster finish or an ultra smooth polished surface.
Cost: They both cost around $50-$100 per sq ft.

The production of Portland cement is very energy intensive, but you can use waste materials as aggregates in concrete countertops. Absolute Concrete Works in Seattle uses a glass fiber reinforced concrete mix to make countertops, fireplace surrounds, sinks and more.

TV shows encourage homeowners to turn their existing dark countertops in light colored faux marble designs. DIY epoxy kits allow you to paint them white and then add fake gray veining. A top clear sealant coat is supposed to protect the paint. It’s a seemingly easy way to refresh your kitchen, but please be aware of the dangers of epoxy including the strong fumes generated, the exothermic chemical reaction of the components that melts plastic, the need to properly ventilate your work space and the short lifespan of these cheap DIY products.