Terrazzo Flooring – Ultimate Guide to Elegance and Durability

Terrazzo is elegant and timeless with its long-proven history of durability, sustainability, and performance. Moreover, it was one of the first recycled composite materials. Terrazzo flooring is applicable both indoors and outdoors. It is familiar for its function in Airports, Healthcare centers, educational institutions, as well as residential areas. It is typically useful as a finish for floors, stairs, and walls.

What is Terrazzo?

It is a composite flooring system combined with chips of marble, quartz, granite, or glass chips in Portland cement, modified Portland cement, or resinous mix. The Terrazzo is poured, cured, ground, and polished.

Composition of Terrazzo Flooring Materials

The composition of terrazzo flooring materials involves a careful selection of aggregates, binders, and additives to create an aesthetically pleasing surface.

1. Aggregates
   • Marble chips: Mainly used in traditional terrazzo flooring methods. They provide a classic and elegant appearance.
   • Glass chips: Often used in modern terrazzo flooring methods. They add color and visual texture.
   • Granite chips
   • Other stone aggregates: quartz, onyx, and quartzite – to achieve specific color combinations.
2. Binders
   • Cement-based binders: Portland cement to hold aggregates together.
   • Epoxy Resin binders: Epoxy resin to used for strong adhesive properties and glossy effect.
3. Additives
   • Pigments: Color pigments are added to achieve the desired color.
   • Polymer additives: Polymer additives are added to enhance workability and performance.
   • Sealers and hardeners: These are added to improve durability and longevity.
4. Divider strips
   • Metal divider strips
   • Plastic divider strips
5. Substrate
   • Concrete Substrate: A solid, level concrete base is often prepared to receive the terrazzo mixture.
   • Moisture Barrier: A moisture barrier is applied to prevent moisture from affecting the integrity of the terrazzo.
6. Installation adhesives
   • Thin-set mortar
   • Epoxy adhesive: applied for resin-based terrazzo
7. Finishing layers
   • Grinding and Polishing Materials
   • Sealing Compounds

Pros of Terrazzo Flooring

• Beautiful and aesthetic: Various materials and mixes add interest
• Unique Flooring: Available in various colors, textures, aggregates, and customized designs.
• Heat Resistance: Very good at retaining heat and suitable for underfloor heating systems.
• Resistance to molds and bacteria
• Durable, Easy to maintain
• Seamless flooring: can be poured in situ
• Environment-friendly- option

Cons of Terrazzo Flooring

• Expensive: varies on the type of aggregate chosen
• Failure due to cracks: cracks may appear if not installed properly
• Cold and hard under feet

Aesthetics

Colors

Distinctive color options and their combinations give rise to various designs, just like if we design on a blank canvas.

Sizes

• Precast tiles are available in a variety of standard sizes. The edges can be square or chamfered. In In-situ terrazzo is cast in 4’x4’ in sections to maintain even distribution.
• Tiles: 300×300,300×600,400×400,600×400,600x600mm (not exceeding 600mm in its greatest dimension).
• Thickness: Most common are 1/4”,1/2”3/8”,5/8”
• The thickness of epoxy-based tiles is less when compared to cement terrazzo.
• Cut to size: Custom order as per design.

Types of Surface Finish for Terrazzo Flooring

• Polished: high gloss mirror-like surface, gives a contemporary effect for residential and commercial projects.
• Honed: low gloss, suitable for anti-slipping surfaces.
• Sandblasted: Similar to Matt’s surface with the anti-slipping surface.
• Antiqued: Preferable for Traditional styles, Rustic styles, etc.

Primary Installation Methods

Floors can be either poured in situ or using precast tiles.

In Situ

For In situ, the mixture combines with cement binder like concrete or with epoxy resin. This mixture is poured in place to achieve a monolithic cast flooring system. Mineral pigments are added for various color options.

Precast Tiles

To form Precast tiles, molds are used to form the desired shape into which the mixture is poured. It is then baked in an oven or kiln until it becomes solid.

A water jet cuts into different shapes, patterns, or logos. The use of water jet in terrazzo floors creates highly detailed customizable patterns creating unique floor designs.

• Matrix: The Portland cement and water mix or non-cementitious binder that holds the marble chips in place for the terrazzo topping.
  • Cementitious Matrices consist of Portland cement, pigments, and water.
  • Resinous Matrices include epoxy, polyacrylate-modified cement, and polyester compositions used for thin-set applications.

Rustic Terrazzo: A variation in terms of grinding and polishing, the surface is washed with water or otherwise treated to expose the marble chips.

Types of Terrazzo Floors and Installation Methods:

How to Install a terrazzo floor?

The Terrazzo floor is installed either in situ or in tiles. Confirm the selection of the type of aggregates, pigments, and divider strips with the terrazzo installer.

• 1. Prepare the surface
• The top layer of concrete is removed from the top surface so that a strong bond is created between concrete and terrazzo. Any presence of cracks is filled on the concrete surface. The floor is leveled, and any presence of moisture is removed by the moisture mitigation system.
• 2. Use divider strips as per design
• Divider strips (metal or plastic) are affixed to the subfloor to separate colors, design, and control of expansion joints.
• 3. Mix terrazzo
• Mix the terrazzo using mixing equipment and as per the specifications.
• 4. Pour terrazzo
• After the divider strips are placed, pour terrazzo to the flooring surface and using a trowel, spread and distribute additional aggregates like marble chips and glass pieces over the floor. Additional chips can be poured to create a denser composition.
• 5. The floor is then compacted by a mechanical roller to wipe off excess cement and water. Allow the floor to cure for 48 hours.
• 6. After the floor is cured, use a grinding machine to smooth the floor and polish the surface.
• 7. Apply grout mixture if any pinholes are present.
• 8. Polish and apply a sealer as per the supplier’s directions. Cement-based terrazzo must be sealed with a water-based sealant to prevent stains.

• Cementitious Terrazzo
• Rustic Terrazzo
• Epoxy Terrazzo

1. Cementitious Terrazzo

Sand Cushion Cementitious Terrazzo

This cement-based system is physically separated from the structural slab with an isolation membrane and a sand layer. The under-bed (sand layer) is reinforced with a wire mesh. Divider strips are best placed at a 5 by 5-foot distance. The overall thickness varies from 2.5 to 3″ including terrazzo topping.

Bonded Cementitious Terrazzo

In this method, the Underbed (sand, cement) acts as a bond between the concrete slab and terrazzo topping. Bonded terrazzo is 1 ¾” to 2 ¼” thick including ½” terrazzo topping. Divider strips are to be placed at fixed distances to avoid cracking.

Monolithic Cementitious Terrazzo

Terrazzo topping (1/2” thickness) is directly bonded to the concrete structural slab without any under bed. This method is suitable where time and budget are the constraints. Divider strips are placed between them at regular intervals to separate colors or as a decorative feature.

2. Epoxy Terrazzo

Thin-set

Thickness varies between ¼” to 3/8” and dividers must be placed precisely where structural crack exists.

    Epoxy for Resin Terrazzo – A resin matrix is placed over the concrete slab. It is a lightweight flooring suitable for multipurpose use, provides resilience, and has the greatest tensile, compressive, and flexural strength.

   Polyacrylate for Cement Terrazzo – A polymer cement mix is placed on the concrete slab. It is well suited for use in areas subject to moisture vapor transmission.

3. Rustic Terrazzo

A textured surface that is non-grounded is used as a terrazzo topping. It has slip-resistant properties, useful for exterior works. Thickness ranges from 1/2” to 6”.

Terrazzo Tiles

Terrazzo tile flooring is similar to installing ceramic tile by using an adhesive and grout system.

Sustainable Considerations

These floors last for the life cycle of a building. Environmentally friendly products are also useful for resealing the floors. They are recyclable. A major part of the floor is constituted with naturally occurring materials/recycled content with zero VOC materials; therefore, it is a part of sustainable green construction.

Innovation in Terrazzo Floors:

Terrazzo tile floors are embedded with light-conducting channels to create a dynamic experience of light. The lights create a twinkling effect in the presence of light, movement, and shadows.

You can find more about Innovation in Terrazzo floors at

http://www.sensitile.com/materials/families/sensitile-terrazzo/

Learn about different floorings here – https://thearchspace.com/category/flooring/