Grout is used to fill the space between the concrete conjunctures and to support them. Grout can be water-resistant. However, water or other liquids will most likely penetrate the joint and reach the backing. There are three major classifications of grouts
- Portland cement based grouts
- Epoxy-based grouts
- Furan resin grouts
Of these three, there are two basic types: sanded or non-sanded. Sanded grouts should be used when grout joints are 1/8" or larger. Non-sanded grouts should be used in a joint 1/8" or smaller.
||Grout joints 1/8" or larger|
||Grout joints 1/8" or smaller|
Sanded Portland Cement Grout
This is an on the job mixture of cement, fine sand and water. Its specifications are found under ANSI 108.10 1985. On the job mixes are used for large jobs and normally can only be mixed in white or gray. The color is dictated by the cement color used.
The following three grouts are commercially prepared grout available from a variety of manufacturers:
Non Sanded Portland Cement Dry - Set Grout
This grout consists of Portland cement, fine fillers, a water-retentive additive, and colored pigments. This grout is designed for use in surfaces that are dry when the grout is applied. The water retentive additive allows the grout to stay moist until the cement cures properly. Without the additive, the dry tile would wick out the water before the cement can cure.
Sanded Portland Cement Grout
This grout consists of fine graded sand, Portland cement, sometimes water retentive additives, and colored pigments. This grout should be applied to moistened tile, no puddle water in the joint, and damp cured.
Latex - Modified Sanded Portland Cement Grout
This grout is the same as the above grout. However, a latex polymer is either incorporated into the pre-mixed powder or added during mixing. This grout has increased water resistance and bonding characteristics.
Note: Modern grout manufacturers have developed their products to be as water-resistant and uniformly colored as science allows. Again, they want the grout and other products they produce to succeed.
The following grouts do not have Portland cement as their hardening/curing substance. They have special attributes necessary or desirable in some installations. Normally, the applications involve the necessity of chemical or thermal resistance. These grouts also have sanded and non-sanded type fillers for varying joint widths. However, sand is normally replaced as the filler with minerals designed to resist the specific chemicals called for in the installation.
100% Epoxy Resin Grout
Like the name suggests, this grout is 100% epoxy. While no water is present in the mixture, clean up is still accomplished with water. The grout consists of epoxy resin, silica fillers, pigments, and a hardener. These grouts are resistant to staining, have very low water absorption, and have higher compressive strength than concrete. 100% epoxy grouts are also highly resistant to chemical attack
Modified Epoxy Grout
This grout has an additional ingredient of Portland cement. The characteristics of this grout are similar to standard Portland cement grouts. However, they are harder, form greater bonds, and are more stain resistant. They are not necessarily any better than Portland cement based grout in their resistance to chemical attack.
Grouting Tip: These grouts are more expensive and more difficult to install than standard Portland cement grouts. Also, when chemical resistance is the goal, the actual chemical involved should be considered and tested against the intended grout ingredients. This will ensure that the intended grout can resist the chemicals that will be present in the finished job.
The name furan comes from the ingredient in the grout called furfuryl alcohol. This means that no water at all is used in the mixture. It is generally considered to be highly chemically resistant especially when acids are the problem to be encountered. They are much more difficult to install than any other grout. Normally, the grout is manufactured in a black color only. Bare in mind that furan grout will react with some chemicals that epoxies will not and vice versa. Again, careful consideration is necessary in establishing what chemical needs resisting. There are other grouts in a class all by themselves. These include grouts that are the pre-mixed liquid types which are available in a variety of container types. They may or may not contain silicon or other products. They are available in a sanded or non-sanded configuration.
Caulking - Type of Grout
There is a very popular type of grout in this class that includes the caulking type of grout that is available in tubes squeezed by hand or designed for use in a caulking gun. These grouts can be very close to the color of Portland cement grout in the installation.
Adhesives are designed for fast, precision bonding applications and will simplify processes that require critical alignment or exact positioning.
This adhesive is mixed using cement, sometimes sand, and water to form a trowel able or brush able consistency. Generally, this mixture can only be used on a substrate or mortar bed that is still plastic or uncured. The use of this adhesive is sometimes called wet-set and was the method used to bond conjuncture prior to the invention of thin set. While an old method, it is still used today and is still a very good one.
It is sometimes called Portland cement mortar and many companies manufacture this product. This product is used to bond dry working area directly to the backing or substrate. Basically, thin set is cement, sand, and an additional ingredient called Smethylcellulose. Methylcellulose is the ingredient that holds water in the thin set allowing the user to set dry work area. Thin set is available in two types, dry-set Portland cement mortar and latex-modified Portland cement mortar. Latex Portland cement mortar has latex modifiers mixed with the traditional ingredients. Each company may have several different types of thin set in their individual line. Some may have higher bonding properties, faster drying times, higher water resistance, and reduced shrinkage factors when applying the thin set in a thicker application. The user mixes potable water with the dry ingredients to form an adhesive. Thin set is manufactured in white or gray in color. Generally, white is used for walls and counters and gray for floors.
Organic adhesive or mastic can be used on floors and walls. It is used like thin set to bond tile directly to a backing or substrate. However, special precautions must be followed in their use. These products are a pre-mixed adhesive that is commonly packaged in pails or other watertight containers. They can be categorized in two types.
|Type 1 mastic
||For floors and walls either wet or dry|
|Type 2 mastic
||Is generally used for dry wall use only|