Installer Update: Getting Cement Grouts Right the First Time
May 2nd, 2008

May-June 2008

By Pierre Hébert

Next to tile, grout is the most visible part of a floor or wall installation, and when properly installed, helps add significant value and beauty to a room. With careful preparation and installation techniques, many of today’s common issues with cementitious grouts can be prevented, including shading and mottling, cracking and pinholes, efflorescence and powdery grout. Help minimize repair-related labour costs and ease long-term maintenance for customers by keeping these tips in mind.

Successful cement grout installation

DO prepare joints before installing grout. To help prevent discoloration of grout, remove excess mortar or mastic left in grout joints so that the grout will fill at least 2⁄3 of the depth evenly. Also, before grouting, use a vacuum to eliminate excess debris such as sanding from dry wall mud or saw dust.

DO use proper tools for grouting. To prevent pinholes and powdery-looking joints, always use a slow-speed drill to mix the grout to a uniform paste. Do not mix by hand, because extra water is often wrongly added to facilitate hand-mixing.

When it is time to clean the grout, squeegee off excess grout diagonally using a sharp-edged rubber float. Next, remove residue with a durable cellulose sponge, as opposed to a collapsible foam sponge. A cellulose sponge helps to prevent excess cleaning water from pooling in the grout joint, which can promote unwanted efflorescence.

DO protect the grout installation until fully cured. To promote color consistency, protect the grout installation from exposure to dust, dirt and other contaminants until the grout has fully cured or dried sufficiently. Ensure that the installation is protected from excessive air movement, so that the entire installation dries evenly. Do not use fans to speed up curing time, as this can dry the surface of grout faster, which risks blotchiness, surface cracking and pinholes. For best protection, apply a sealer as soon as permitted by the sealer manufacturer.

DON’T install grout under extreme temperatures or humidity without first consulting the manufacturer. Temperature, humidity and wind affect the way a grout cures; when not controlled, they can lead to expensive grout-related problems. Cementitious grout best cures when installed and maintained at between 70°F and 80°F (21°C and 26°C) with 50% relative humidity. Ideally, it is best to store grout and the mixing water at this temperature for 24 hours before the installation. Always consult grout manufacturer for specific instructions.

In summer, grout during the coolest part of the day and take steps to minimize air movement throughout the curing process. In winter, the installation temperature should be above 50°F (10°C) and remain well above freezing for up to 21 days while the grout cures (consult the Technical Data Sheet for cure time).

DON’T use too much water when mixing the grout. Always refer to manufacturer’s mixing instructions before mixing the grout. Adding too much water to grout powder can result in a lighter shade of grout, as well as latex migration and efflorescence. Adding too little water to powder prevents the grout from achieving proper hydration of the cement, resulting in weaker joints and a darker grout color. When more than one unit is being used, dry-blend together all units of grout powder to avoid shade variation between different lots.

After the grout is thoroughly mixed, allow it to sit (“slake”) for up to 10 minutes. Remix without adding more water, thus optimizing grout color consistency and helping to prevent cracking, pinholes and powdery joints.
DON’T use too much water when cleaning the grout. Only attempt to clean the grout once the grout no longer transfers to the finger after being gently touched. This typically takes 10 to 30 minutes with nonporous tiles. With porous pavers or quarry tiles, pre-sealing the tiles will help during rinsing. The appearance of a grout haze on the tile surface may prompt the desire to rinse, but rinsing grout too quickly can cause pigment to wash out, negatively affecting the shade.

Introducing too much moisture onto the surface of new grout can spawn all kinds of problems, including uneven curing, spotting, discoloration, efflorescence and powdery joints. Thanks to advancements in latex-modified grouts, less is better when it comes to preventing latex migration. Take precautions to ensure that no standing water remains on the joint surface following a grout installation, as the potential problems are easy to prevent but a nuisance to repair.

Pierre Hébert is MAPEI’s Manager of Technical Services in Canada and supervises the MAPEI Technical Institute. He has worked in the technical field for the past 16 years and previously worked as a foreman with a floor installation company.

CTDA’s Certified Ceramic Tile Salesperson: Deliver value with every product transaction!
May 2nd, 2008

May-June 2008

As the number of Certified Ceramic Tile Salespersons (CCTS) continues to grow, so does the role of this important designation. In today’s competitive marketplace, knowledge is power. Certification demonstrates to your customers and competitors that you and your employees have the most current ceramic tile industry expertise available. You can answer questions, solve problems, and identify the right tile to meet the customer’s needs. Save time and money. Become the strategic partner your customer needs in today’s marketplace.

CCTS demonstrates the knowledge those tile professionals have of the ceramic tile industry, of estimating, installation, and related issues. For those individuals, it delivers professional recognition for your knowledge and technical competence. For employers, certification distinguishes sales professionals in one company from those in another. It promotes your company’s industry expertise, and demonstrates your ability to meet growing customer demands.

Putting CCTS to work in your company

CCTS is designed as a self-study program, which allows you to incorporate it without the addition of training or other human resource personnel. Applicants must be currently employed full time and have been for at least the past two years in the ceramic tile industry. Applicants for certification are sent a CD-ROM Study Guide and sample tests. The Study Guide prepares applicants for the certification exam by leading them, step-by-step, through tasks, outcomes and review questions on a representative sample of the technical information addressed by the certification exam itself. Applicants may work through the Study Guide individually, at their own pace, or in a group setting with a study leader. In each case, review questions at the end of each outcome help the applicants chart their progress.

Three pretests help applicants determine when they are ready to take the final test. Applicants take one pretest before they begin the program to measure their strengths and weaknesses. Applicants take a second pretest after completing the guide to see what they have learned from their study. The third pretest serves as a means of review before taking the final certification test.

Applicants register for the final test in advance, after they have completed the CCTS Study Guide. Testing is offered regularly at major industry events, including Surfaces, Coverings, and the CTDA Management Conference. In-house testing is also available at your location.

Certification offers the in-house benefits of an outstanding industry-specific training path to meet human resource needs for company advancement and professional promotion. The CCTS program can help your company meet or even establish corporate training requirements without the additional cost of developing a program. Successful certification can be an appropriate incentive for promotion within your corporate ranks and/or a salary increase.

What are you waiting for?

CTDA’s CCTS is affordable, accessible, and increasingly the distinction among ceramic tile professionals.

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