Grout is Mortar and Mortar is Grout.

They are both composed of the same basic ingredient that is Portland Cement. The only difference is the ratio of Portland cement to sand and lime in each mix and their respective uses.

Let’s start with Mortar. Mortar is the glue which holds all masonry products together whether it’s fixing Marble, Ceramic Tile, Bricks and Blocks to a surface, or in the case of bricks and blocks, to themselves.

Years ago, marble slab, marble tile and ceramic tile was fixed in place or to a surface with a semi-damp mix of mortar, sand and lime. This was called a “mortar bed,” or “thick mortar bed” and is required to be at least 3/4″ thick.

The tiles where then soaked in water. This was to absorb water into the body of the tile and set in place on the “mortar bed” with a dusting of “pure” Portland cement over the surface of the bed.

In approximately 48 hours the surface was able to safely take on traffic. This is called “The Wet Set Method” and has been the standard for over two thousand years.

This method is still used today and is usually referred to as a “Mud Job.”

The modern method taught in my video “How to Install a Marble Bathroom Floor” DVD is called “The Dry Set Method.”

This method was developed in the late 20th century with the discovery of mortar accelerators that where added to a bag of “This Set Morter”…this is also known as “The Thin Set Method”.

Unlike the “Mortar Bed” method that is required to be at least 3/4 of an inch thick and sometimes more…the “thin set” method requires a minimum of 3/16 thick to 1/4 inch thick.

Thin Set is applied with a notched trowel. The notch in the trowel determines the thickness of a tile.

A 12×12″ marble tile or ceramic tile requires a 1/4×1/4″ notch to a 1/4×3/8″ notch in the trowel depending on the flatness of the surface..A 4×4 or 6×6 ceramic wall tile will require a 3/16″ notch . A latex adhesive can be used on drywall (sheetrock) or plywood and only in a dry area.

Modern “Thin Set Mortar” has advanced latex additives that are added to a dry mix to facilitate a stronger bond and increase it’s adhesive ability. This is known as “Modified Latex Thin Set Mortar.”

HOW ARE TILES SET USING A MIX AND A TROWEL?

The notch of the trowel creates an air pocket when applying the mix with the trowel tool. .The tile is then pressed or “set” into the mix and the air is forced out. This causes a vacuum and the tiles adhere to the surface causing the tile to remain fixed until the thin set mortar drys…usualy about 24 hours.

The next steps are to apply the grout.

Now let’s discuss GROUT. Grout is also a Portland cement mix or we can even say “recipe” but with some different additives.

Grouts do not normally have the adhesive characteristics of Thin Set Mortar but do have “Pigments” added to them. This imparts a color into the grout.

Not having the adhesive quality of a Thin Set - grout may be weaker in strength, both compressive and tensile, Compressive Strength means how much of a “Load” it will take when a force is applied to the surface over a surface. Tensile Strength means how much of a “Load” it will take when a force is applied to a surface over a span or when the surface is suspended between two points like columns or a framework.

However, not having the characteristics of thin set and being more condusive for being spread around with a “grout float” or “grout trowel”; grout is perfect to fill in the gaps in what we call “Joints”. Joints are what remain between the tiles after the tiles have been set. Marble Tiles are normally set with joints from 1/16″ to 1/8″ wide and up to 1/4″ to 1/2″ wide with Ceramic Tiles and Bricks. Joints are necessary to insure proper spacing between tiles and to “lock In” the entire floor or wall.

Grout has also been “down the development road” in the later part of the 20th century.

There are additions of stronger and more acid resistant types for food service areas, factories and institutions.

Grouts today come in a mortar base and a resin and epoxy base, thereby allowing a grout to become virtually impervious to any environmental hazards such as acid spills, bacteria and chemical attacks.

These type grouts are not common in residential applications, although the epoxy has on occasion been used in some style residential applications. This is for the reason that it’s resistance to staining and bacteria growth is of a higher standard.

Epoxy grout is very expensive and extremely hard to apply. It can be improved by the application of a “sealer” when using a Portland cement grout instead of epoxy.

Sealers should be applied no sooner than one week after application. The grout requires a minimum of one week to acquire a full cure; (full cure meaning; the absence of all water or moisture). This enables the “sealer” to properly adhere to the grout surface and protect the grout from stains and bacteria growth.

Thanks So Much For Visiting!

Sincerely,

Ben Michalski