Section 8: Methods of Installation
8.1 Tradtional Installation Equipment and Procedures
The construction equipment and installation procedures required for each project in each region of the world are unique. With that said, it would not be possible to list all of the tools, equipment and procedures involved in the installation of mass transit tile applications. This section will present the most common tools, equipment and installation procedures required for each phase of the tile or stone installation. Tool and equipment requirements are determined by the phase of the installation shown below, and further defined by the type of construction, type of finish material, and the type of adhesive installation.
Installation Procedures, Tools and Equipment for Mass Transit Installations
Substrate and Finish Material Surface Preparation (See Also Section 2.3)
Access for Preparation and Installation (Rolling Scaffolds for Vertical Work)
Mixing of Adhesives
Installation of Adhesives
Installation of Finish Material
Installation of Grout/Sealants
Clean-Up and Protection (See Section 9)
Weather and Substrate Protection
The optimum conditions for installation of ceramic tile and stone pavers are temperatures between 60° and 80°F (15° and 25°C), with 50% relative humidity. However, these conditions are atypical, so provisions must be made for variations in climatic conditions. Protection applies to the substrate, the installation of the adhesives and grouts, and also the storage and handling of the finish material.
As a general rule of thumb, follow the 18° Rule; For every 18°F (10°C) above 70°F (21°C) cement based and epoxy based materials cure twice as fast. For every 18°F (10°C) below 70°F (21°C) cement based and epoxy based materials take twice as long to cure.
Hot Temperatures
Protection or corrective action is required if either ambient air or surface temperatures of substrates and finishes go above certain thresholds during installation. Temperature thresholds vary with the types of adhesives, but generally, elevated ambient air (80–100°F [27–38°C]) and surface temperatures will accelerate setting of cement, latex cement, epoxy and silicone adhesives. Washing and dampening floors and walls will not only help to remove contaminants, but will also serve to lower surface temperatures by evaporative cooling of the substrate. Shading surfaces that may be in direct sunlight is also an effective method for lowering surface temperature, but if ambient temperatures exceed 100°F (38°C), it is advisable to defer work to a cooler period of day or the evening. If work cannot be deferred, it is also possible to cool additives (e.g. latex buckets or epoxy liquid pouches stored in cool water) in conjunction with the above techniques.
Conventional portland cement tile-setting beds, thin-set mortars, cement plasters and stuccos are often permanently damaged when subject to hot, dry temperatures or desert climates immediately after installation. High temperatures can quickly cause the water content of the mortar required for portland cement hydration, curing and strength development to evaporate. In addition, rapid drying can cause mortar to crack, crumble or lose bond. Waterproofing membranes, anti-fracture membranes, epoxy adhesives, epoxy grouts, epoxy waterproofing membranes and most other products will also be affected by hot working temperatures. Flash setting and reduced working time can result. It is important to note that surface temperature is more important than air temperature. Therefore, monitor the surface temperature of the installation. The use of premium latex-fortified mortars (e.g. LATICRETE® 254 Platinum or LATICRETE 317 gauged with LATICRETE 4237 Latex Additive) allows installations to be made at higher temperatures due to the fact that they have longer working properties. LATICRETE 3701 Mortar Admix in thin-sets, plasters, stuccos and other portland cement mortars allow work to continue in hot weather without costly delays or damage. Installations can be made in temperatures as high as 90°F (32°C) under normal circumstances. LATICRETE latex fortified mortars are not damaged by high temperatures and thermal shock after placement and eliminate the need for wet curing. Rapid setting materials will provide for greater challenges when working in high temperatures and should be used with caution.
Tips for working in hot temperatures:
1. For best results, always ship and store installation materials at temperatures between 40° – 90°F (5° – 32°C) to extend the shelf life and working time. Do not store products in direct sunlight. If installation materials are too warm, they should be cooled to the specified temperature range for that specific product.
2. Dampen or wet down substrate surfaces to not only clean the area, but to lower the temperature and lower the absorption rate of the substrate. Sweep off excess water just before mortar is applied. This step will extend the open time and working time of the installation materials.
3. Stir latex additives thoroughly before mixing with thin-sets, grouts, plasters, stuccos and other portland cement mortars.
4. Due to the rapid rate of moisture loss and portland cement dehydration at temperatures >90°F (>32°C), cover installations with polyethylene sheeting for 1–2 days to allow curing at a more normal rate.
5. Low humidity can also accelerate the curing process.
6. Tent off or provide shade when working in direct sunlight.
7. Work during cooler periods of the day (e.g. night, or early morning).
8. Use cool water (where required) when mixing with installation materials.
9. When possible, mix smaller batches of installation materials for optimum workability and immediate use.
10. An infrared or laser thermometer can be used to measure temperature of substrate, installation materials and finish materials.
Cold Temperatures
Conventional portland cement tile setting beds, thin-set mortars, grouts and cement plasters are often permanently damaged when subject to below freezing temperatures immediately after installation. The water content of a mortar turning into ice often results in the portland cement gel structure rupturing with significant loss in strength, flexibility and durability. Subsequent repairs to the damaged work and resulting site delays can be extremely costly.
Protection or corrective action is required if either ambient air or surface temperatures of substrates go below certain thresholds during installation. Temperature thresholds differ for various types of adhesives. Protection and corrective actions to elevate temperatures to optimum range typically involve enclosing or tenting of work areas, augmented by temporary heating. If temporary heating is employed, it is very important to vent units to the exterior of enclosures to prevent exposure to toxic fumes, and also to prevent build-up of carbon dioxide, which can cause carbonation of cementitious materials. Carbonation typically occurs when ambient temperatures during installation are around 40°F (5°C) and only affects exposed surfaces. The length of exposure is a function of temperature. Cement hydration stops at 32°F (0°C) or when water necessary for hydration freezes, while hydration is retarded (substantially slowed) when temperatures go below 40°F (5°C). Concentration of carbon dioxide can be elevated when temporary heating units are not properly vented outside of any protective enclosure during cold temperatures. As a general rule, temperatures should be maintained above 50°F (10°C) during installation of cement, epoxy, and silicone-based products. Some cement adhesive product formulations may allow installation in temperatures close to 32°F (0°C) and rising, however, at this critical ambient air temperature threshold, it is likely that surface temperatures are below freezing due to thermal lag, and hydration or other chemical reaction may not occur at the adhesive interface.
Liquid Latex Fortified Mortars, Screeds and Plasters
The use of LATICRETE® 4237 Latex Additive in thin-sets and LATICRETE 3701 Mortar Admix in thin-sets, grouts, plasters, stuccos and other portland cement mortars allows work to continue in cold weather without costly delays or damage. Frost, ice and thermal shock do not damage LATICRETE Latex Fortified Mortars after placement. Installations with these LATICRETE products can be made at temperatures as low as 35°F (2°C).
Rapid Setting Latex Fortified Mortars
The use of a premium rapid-setting thin-set mortar will also help to accelerate the setting time in cooler temperatures. LATICRETE 254R Platinum Rapid is ideal for this application. In addition, the use of LATICRETE 101 Rapid Latex Admix mixed with LATICRETE 317, LATICRETE 220 Marble & Granite Mortar and other suitable LATICRETE bagged mortars, allows work to take place in cool temperatures and return these areas back into service quickly.
Tips for working in cold temperatures
1. Work during warm periods of the day.
2. Ensure that the surface temperature is within the suggested temperature range for the LATICRETE or LATAPOXY® product being used during the installation and cure period. Consult the individual LATICRETE or LATAPOXY product data sheet and How-to-Install guide for more information.
3. Tent and heat areas that will be subjected to the elements or freezing temperatures during installation and cure periods.
4. For multiple story buildings – areas to receive tile and stone work may be heated from below to aid in “warming up” cold concrete slabs and rooms. Simply placing temporary heating units in areas under rooms scheduled to receive tile and stone finishes in multiple story buildings will help allow the natural rising of heat to warm up these areas.
5. Vent all temporary heating equipment in accord with OSHA (Occupational Safety and Health Administration) and local building code regulations.
6. For best results, always ship and store installation materials at temperatures above freezing so they will be ready to use when needed.
a. If LATICRETE liquid latex admixtures and liquid membranes are ever frozen, allow them to thaw completely before use. Allow the products to come up to room temperature (i.e. 70°F [21°C]). Stir contents thoroughly before use or before mixing with thin-sets, grouts or other portland cement mortars.
b. LATICRETE and LATAPOXY liquid pouches stored in cooler temperatures should be warmed by submerging the unopened pouches in warm water until the material is sufficiently tempered.
c. Acclimate waterproofing membranes, crack isolation and sound control products to their respective usage temperature range prior to use.
d. Store all polymer-fortified thin set mortars and grouting products in a warm area prior to use.
Protection
Due to the slow rate of portland cement hydration and strength development at low temperatures, protect installations from traffic for longer than normal periods. Keep all traffic off of finished work until full cure. For example, installations which will be subjected to vehicular traffic should cure for 7 days at 70°F (21°C) prior to vehicle traffic. Allow extended cure time, based on the 18° Rule, for installation in cooler temperatures. It is important to note that large format tile and stone will also require longer curing periods in cooler temperatures. Suitable protection should be included in the scope of work. For example, the Tile Council of North America (TCNA) of the 2008 TCA Handbook for Ceramic Tile Installation states “Protecting New Tile Work” states: “Builder shall provide up to 3/4" (19 mm) thick plywood or OSB protection over non-staining Kraft paper to protect floors after installation materials have cured”. In addition, extended cure periods will be required for applications that include multiple layer build ups (e.g. mortar beds, waterproofing, sound control, crack isolation, epoxy grout, etc…). Each component must reach a proper cure prior to installing the subsequent installation product.
Dry, Windy Conditions
Dry and windy conditions can cause premature evaporation of water necessary for hydration in cementitious materials, and result in loss of strength. Latex additives are formulated to significantly reduce this drying effect by coating cement with a latex film. However, in extreme dry, windy conditions coupled with high temperatures >90°F (30°C), even latex additives do not provide adequate protection. It is recommended to provide temporary protection against rapid evaporation of moisture during hot, dry, windy conditions in the initial 36 hours after installation of cement mortars, screeds, plasters/renders and cement grouts, and to augment by damp curing with periodic daily water misting. Cement based adhesives are only susceptible to premature drying between the spreading of adhesive and the installation of the finish, and requires only temporary protection from dry and windy conditions during the open or exposed time of the adhesive.
Wet Conditions
Certain materials used in ceramic tile and stone assemblies can be moisture sensitive. For example, the strength of cementitious adhesives can be reduced from constant exposure to wet or damp substrates. Some materials, such as waterproofing membranes, may not cure properly or may delaminate from a continually wet or damp substrate. A damp substrate may also contribute to the formation of efflorescence (see section 2.5 efflorescence). This is a particular concern not only from normal rain exposure during construction, but also in areas of an installation which may be exposed to rising dampness at ground level, or, in areas where leaks from poor design or construction cause continual dampness in the substrate. When specifying liquid latex, or a dry redispersible polymer adhesive mortar, verify with the manufacturer that the polymer formulation is not water soluble. However, even formulations that are not soluble when dry are vulnerable to rain during the initial set period (typically 12–24 hours). Therefore, it is essential to provide protection from any significant rain or washing within this period to avoid loss of strength and prevent possible fluid or latex migration staining.
8.2 Access for Vertical Installations (Scaffolding)
The selection of scaffolding has a major impact on the productivity and resulting cost of installing vertical and overhead applications of tile and stone. The comfort and convenience for installers, as well as the ease of transport, assembly and handling of scaffolding all contribute to the efficiency and quality control.
Types of Scaffolding1
Veneer Scaffolding
Tubular Frame Scaffolding
Adjustable Tower Scaffolding
Powered Mast Climbing Work Platforms
Multi-Point Suspended Scaffolding
Veneer Scaffolding
This is the simplest, most efficient, lightweight type of scaffolding. This equipment is used only for walls less than 10′ (3 m) high. The system consists of a metal frame with adjustable, stabilizing legs that do not require cross-bracing, and wood or metal platform planks. Vertical adjustment can be made in small 3" (75 mm) increments.
Tubular Frame Scaffolding
This is the most common type of scaffolding, consisting of a tubular metal frame and cross-braces which give the system stability. This system is most efficient in applications under 30′ (10 m) in height, because it is a stacked system. Some advantages are that the components of the system are very common, it adapts well to recesses and projections in walls, and it is the easiest type of system to enclose for hot or cold weather protection. Disadvantages are that this type of system can only be adjusted in large increments at each level of the frame, and that each successive level must be built before it can be stocked and occupied.
Adjustable Tower Scaffolding
Most adjustable scaffolding consists of a base, towers, cross-braces, a carriage, a winch (hoisting) assembly, guardrails and a plank platform. These systems are most efficient on buildings up to 75′ (23 m) in height, but can be used up to 100′ (30 m). The hand operated winch raises the platform along the carriage towers. This system can be easily adjusted in any vertical increments, and the entire assembly can be lifted and transported by forklift to adjacent walls. Many proprietary designs provide separate loading/stocking and working platforms. Studies have shown that adjustable scaffolds can increase labor productivity by 20% over conventional frame scaffolding.
Powered Mast Climbing Work Platforms
Powered mast climbing work platforms are electrically or hydraulically powered and consist of a trailer base unit, a platform, and one or two tower masts on which the platform rides. Powered systems, depending on the components, can be used on buildings between 300–500′ (91.5–152 m) in height, but the cost of frame erection makes them most efficient on buildings less than 100′ (30 m) in height. Powered systems have all the advantages of adjustable scaffolding, as well as significant safety features such as built-in guard rails, safety stops, and speed controls. The primary disadvantages are the cost and the lack of availability in some regions of the world.
Multi-Point Suspended Scaffolding
Multi-Point Suspended Scaffolding is suspended from wire ropes attached to outrigger beams which are anchored to the roof or intermediate floor structure, or, to temporary structural counterweights. These systems are powered either by hand winches or power driven equipment. Suspended scaffolding is typically used for high-rise construction, and becomes cost-effective at building heights of 100–125′ (30–38 m). Suspended scaffolding must be engineered for each construction site, usually by the scaffolding supplier and the building contractor’s engineer. These systems have the same advantages as adjustable and mast climbing systems. In addition, there are no obstructions between the wall and the installers because suspended systems have no cross-bracing. Overhead protection is typically required by safety regulations due to work that progresses above, making overhead loading difficult unless the platform protection has a hatch opening.
8. 3 Finish Material Preparation
Cleaning of the tile/stone back and substrate surface prevents contamination from inhibiting adhesive bond. Preparation and cleaning of substrates are covered in Section 2.3. While careful consideration is often given to the preparation of the substrate, preparation and cleaning of the finish material bonding surface is an often overlooked specification item or quality control checkpoint. Considerations are dependent on the type of finish material.
Types of Finish Materials
Ceramic and Porcelain Tile
The bonding surface of the tiles may be contaminated with dirt or dust from normal manufacturing, storage and handling. Porcelain tile may have a coating of a release agent (known by terms such as bauxite or engobe) which prevents fusion of the tile to kiln surfaces during the firing process. The type, amount, and degree of presence of the release agent will vary according to manufacturer, tile type or production batch. It is recommended to wipe each tile with a clean, damp towel or sponge just prior to installation to maximize adhesive bond. Cement-based, dry redispersible polymer cement or latex cement adhesive mortars can be applied to a damp, but not dripping wet surface (see Section 2.3 – Moisture Content of Concrete).
Quarry Tile
Quarry tile typically has a rougher, more open pore structure and many have a ribbed back configuration which is manufactured specifically for demanding applications (e.g. mass transit, commercial or industrial floors). As a result, quarry tile is less susceptible to contamination due to the safety factor provided by both mechanical and adhesive bond. There are no specific cautions other than to remove normal dirt caused by storage and handling with normal cleaning techniques prior to installation.
Stone
Stone can be manufactured and supplied with a wide variety of finishes. In addition, the bonding side of the stone can be milled, cut or finished in various profiles. In similar fashion to ceramic and porcelain tiles, the backs of the stones must be free of any cutting/fabrication dust, or weak stone/water slurry. Stones must also be suitable for the intended use and should not contain elements that can inhibit its bond. Precautionary measures should be taken when installing moisture sensitive stones and agglomerates. (See section 7.2 Epoxy Adhesives).
Many stone types are being supplied with resin-backed mesh (e.g. polyester, epoxy, etc…), plastic, metal honeycombing, etc… in an effort to stabilize and prevent the stones from cracking during shipping, handling and installation. It is important to verify that the backings are well adhered, stable, and suitable for the intended purpose. If the backing loses adhesion to the stone itself, the stone installation will fail (see figure 8.4). The backing and backing adhesive must be water-resistant if the stone finish is exposed to moisture. In addition, the adhesive mortar must be compatible with the backing material. In many cases, an epoxy adhesive may be the only alternative for the installation of stones with these various backing types. Outside of any test reports to the contrary, an epoxy adhesive is the safe approach to installing stone with unusual or “non-natural” backing. Specifiers should be aware of the fact that an impervious epoxy adhesive and an impervious backed stone may create installation issues on exterior applications, in regards to condensation and diminished vapor drive through the stone finish. On the other hand, some backings are compatible with latex-fortified portland cement based mortars. These backings may include a layer of sand which has been broadcast into the resin to facilitate mechanical bond (see figure 8.9).
8.4 Adhesive Mixing Equipment and Procedures
Equipment and tools required for mixing of adhesives are primarily dependent on the type of adhesive and construction site conditions, such as the size of project.
Types of Adhesives and Equipment
Latex Cement Based Adhesive Mortars
Manual Mixing
Bucket, Trowel and Mixing Paddle
Mechanical Mixing
Rotating Blade (Forced Action) Batch Mortar Mixer (Figure 8.8)
Low Speed Drill (<300 rpm) and Non-Air Entraining Mixer Blade (Figure 8.7)
NOTE: Rotating drum type concrete mixers are not suitable for mixing adhesive mortars. In mixing cement adhesive mortars, always add the gauging liquid (water or latex additive) to the mixing container or batch mixer first. Begin mixing and add the dry cement based powder gradually until all powder is wet, then continue mixing continuously for approximately one minute or until mortar is wet and plastic. If using site prepared powder mixes of portland cement and sand, add the sand first until it is wet, and then add the cement powder. Take caution to prevent over-mixing by blending only until the mortar is wet and plastic in accordance with the manufacturer’s instructions. Over-mixing can entrap air in the wet mortar and result in reduced density (high absorption will reduce freeze/thaw stability) and strength.
Epoxy Adhesive
Manual Mixing
Bucket and Trowel
Mechanical Mixing
Low Speed Drill (<300 rpm) and Non-Air Entraining Mixer Blade
The mixing instructions for epoxy adhesives vary according to the manufacturer’s formulations. The most common epoxy adhesives are three component products, which involve mixing two liquid components (resin and hardener), and a powder component (silica filler). The liquids are mixed together and blended before adding the filler powder. There are several important considerations in mixing epoxies. First, the chemical reaction begins immediately upon mixing the epoxy resin and hardener; so the clock is running at this point. Because the “pot” or useful life of the adhesive may be relatively short (1 hour) and can be further reduced by ambient temperatures above 70°F (21°C), all preparation for mixing and installation of the epoxy adhesive should be made in advance. Mixing should also be made in quantities that can be installed within the stated pot life under installation conditions. Most epoxy adhesives cure by an exothermic (heat generating) chemical reaction, which begins with the mixing of the liquid components. The useful life of the epoxy not only begins before adding the filler powder, but the heat generated may accelerate the curing process in many formulations. Removal of the mixed epoxy from the mixing container is one technique used to dissipate heat generation and minimize set acceleration. Liquid components may also be cooled if anticipated ambient or surface temperatures will significantly exceed recommended use temperature range. Conversely, epoxy adhesive cure is retarded by cold temperatures, and the curing process can stop at temperatures below 40°F (5°C); the curing process should continue unaffected if temperatures are raised.
Mortar Beds/Renders (See Section 7.3)
Aluminum Straight Edges and Screeds
Concrete/Mortar Bed Finishing Trowel
Wheelbarrows
Square Edges Shovels
Steel Rakes
Walking Boards
Mortar Bed/Tile Shoes
Mortar Mixer
8.5 Waterproofing/Crack Isolation Membranes
The installation of waterproofing is covered under ANSI A108.13 “Installation of Load Bearing, Bonded, Waterproof Membranes for Thin-set Ceramic Tile and Dimension Stone”, and crack isolation is covered under ANSI A108.17 “Installation of Crack Isolation Membranes”. The product standards for waterproofing can be found under ANSI A118.10 “American National Standard Specification for Load Bearing, Bonded, Waterproof Membranes for Thin-set Ceramic Tile and Dimension Stone Installation” and the product standards for crack isolation membranes can be found under ANSI A118.12 “American National Standard Specification for Crack Isolation Membranes for Thin-set Ceramic Tile and Dimension Stone Installation”. Liquid applied membranes are generally considered to be the best options in many applications. These membranes can be applied by brush, trowel or roller. In addition, some of these membrane types can also be applied by airless sprayer. For example, LATICRETE® Hydro Ban™ can be effectively sprayed to increase productivity on large projects.
Spraying Liquid Applied Membranes
In addition to the conventional means of applying LATICRETE Hydro Ban, (see Data Sheet 663.0 and How-To-Install Data Sheet 663.5) the airless spraying technique can be used as an alternate means of application. The following are the guidelines for this procedure. Most airless spray units can be used to apply LATICRETE Hydro Ban. This procedure will refer to the use of the Graco Mark IV Electric Airless Sprayer® and the Graco 5900 HD Gas Powered Airless Sprayer. These sprayers are designed for spraying the contents from a 5 gallon (19 ) pail. Many airless sprayers are similar in design and will accomplish the same purpose.
For more information on the spray application of LATICRETE Hydro Ban, please refer to TDS 410 "Spraying LATICRETE Hydro Ban" available at www.laticrete.com.
A good understanding of the equipment set up, delivery and cleanup procedures are required in order to effectively spray LATICRETE Hydro Ban.
Airless Spray Tip Characteristics: It is important to remember that the spray tip orifice size, in conjunction with the fan width size, determines the spray characteristics of the tip.
Examples: As the orifice size increases, while maintaining the same fan width size, the greater the volume of coating will be applied to the same area. Conversely, the larger the fan width size, while maintaining the same orifice size, will result in the same amount of material being applied over a greater surface area.
Tip Size: LTX521 – has an orifice of 0.021" (0.5mm) and a fan width of 10" (250 mm) holding the nozzle 12" (300 mm) away from the substrate.
Tip Size: LTX631 – has an orifice of 0.031" (0.8 mm) and a fan width of 12" (300 mm) holding the nozzle 12" (300 mm) from the substrate.
The use of a spray tip with a smaller orifice will result in less membrane product being delivered to the substrate requiring multiple passes to ensure a complete coating with optimum thickness.
Understanding Spray Tip Wear
When beginning a project, choosing the right tip size and fan width will determine how effective the spraying process will be. The correct tip size will have a direct bearing on how much material is dispensed. However, spray tips will wear with normal use. Older, worn tips will increase delivery time and product consumption. Therefore, changing the spray tips often will result in greater productivity. Choosing the right spray tip is essential for ensuring a quality finish. It is important to replace a spray tip when it gets worn to ensure a precise spray pattern, maximum productivity and quality finish. When a tip wears, the orifice size increases and the fan width decreases. This causes more liquid to hit a smaller area, which wastes waterproofing membrane and slows productivity. The life of the spray tip varies by coating, so if a tip is worn, replace it. The life of the spray tip can be extended by spraying at the lowest pressure that effectively breaks up the coating into a complete spray pattern (atomized). Do not increase the pump pressure; it only wastes waterproofing membrane and causes unnecessary pump and tip component wear.
The example below demonstrates the spray pattern of new and worn spray tips. As wear occurs, the pattern size decreases and the orifice size increases. As a rule of thumb, it is best to replace the spray tips after spraying 30 –45 gallons (114–171 ) of LATICRETE Hydro Ban.
Spray Guns
Follow the specific airless sprayer and spray gun manufacturer’s written instructions when using their equipment. Typically, a spray gun can be used for both vertical and horizontal applications. Some Spray Guns will allow filtering in the gun handle, and, if so equipped, the filter will need to be periodically cleaned or changed to ensure proper liquid flow through the spray gun and tip.
Application of LATICRETE® Hydro Ban™
Follow all surface preparation requirements outlined in Data Sheets 663.0 and 663.5. The airless sprayer should produce a maximum of 3,300 psi (22.8 MPa) with a flow rate of 0.95 to 1.6 GPM (3.6 to 6.0 LPM) using a 0.521or 0.631 reversible tip. Keep the unit filled with LATICRETE® Hydro Ban™ to ensure continuous application of liquid. The hose length should not exceed 100′ (30.5 m) in length and 3/8" (9 mm) in diameter. Apply a continuous film of LATICRETE Hydro Ban with an overlapping spray. The wet film has a sage green appearance and dries to a darker olive green color. When the first coat has dried completely to a uniform olive green color, approximately 45 to 90 minutes at 70°F (21°C), visually inspect the coating for any voids or pinholes. Fill any defects with additional material and apply the second coat at right angles to the first. The wet membrane thickness should be checked periodically using a wet film gauge. Each wet coat should be 0.015 to 0.022" (0.4 – 0.6 mm) thick. The combined dried coating should be 0.020 to 0.030" (0.5 – 0.8 mm) thick or 0.029 to 0.043" (0.7 – 0.11 mm) wet.
Regardless of whether a liquid applied membrane is applied with hand tools (e.g. paint roller, brush or trowel) or by sprayer, check application thickness with a wet film gauge periodically during installation. This will help ensure that the LATICRETE Hydro Ban is being applied correctly and that the appropriate thickness and coverage is achieved. Bounce back (rebound of unbonded spray) and overspray (spray onto adjacent surfaces) will consume more membrane liquid and affect coverage. To achieve the required film thickness, the coating must be free from pinholes and air bubbles. Do not back roll coating. Allow the LATICRETE Hydro Ban to cure in accord with the instructions in Data Sheets 663.0 and 663.5 prior to the installation of the tile or stone finish. It is important to note that areas not scheduled to receive the LATICRETE Hydro Ban should be taped off and protected from any potential overspray. Expansion and movement joints should be honored and treated as outlined in product Data Sheets 663.0 and 663.5.
NOTES: The operator of the spray equipment must have a working knowledge of the equipment used and be able to adapt to the project conditions as the spraying takes place. As the spray tips wear, adjustments will need to be made. Spray tip selection, pressure adjustments and hose length will have a direct bearing on the results achieved.
Spray Equipment Setup, Clean Up and Maintenance
Follow the airless sprayer manufacturer’s instructions on set up, operation, clean up and maintenance of their equipment. The airless spraying unit should be flushed clean and be free from any contaminants prior to use with LATICRETE Hydro Ban.
Health and Safety
Follow all applicable health and safety requirement when applying LATICRETE Hydro Ban. The use of protective clothing, safety glasses and a dual cartridge respirator are recommended when spraying. See MSDS Sheet on LATICRETE Hydro Ban (available at www.laticrete.com) for complete information.
Airless spray equipment can be purchased by contacting:
Graco, Inc.
The Paint Project Inc.
Sales/Distribution/Service
Industrial Spray Equipment & Systems
71 West St., P.O. Box 1141
Minneapolis, MN 5540-1141
Medfield, MA 02052 Tel. 800.690.2894
Tel +1.508.359.8003
Fax 800.334.6955 or, +1.508.359.8463
www.graco.com
e-mail bob@paintproject.com
8.6 Finish Material Installation Equipment and Procedures
The basic concept of installing various finishes using the direct adhered method is the same. The entire surface of the finish material is adhered, and the basis for evaluating adhesion performance is by strength of a unit area; the size of the finish material is affected only by the logistics of construction and any legal/building code requirements. Adhesives are designed to bond at safety margins of about 250–400% greater than what is typically required by building codes. The reason for the high safety factor is, of course, to compensate for the unforeseen extreme forces such as seismic movement, weather conditions and the difficulty in the quality control of labor. Until sophisticated diagnostic quality control test methods become more readily available and cost-effective, it is foolish to expect maximum specification strength over the entire adhesive interface hidden from visual inspection.
Installation of Ceramic Tile and Stone Finishes
The following are the basic tools and equipment used for the installation of ceramic tile and stone finishes:
Equipment for Application and Bedding of Adhesives and Grout Joints
Notched Steel Trowel
Flat Steel Trowel
Margin Trowel
Hawk
Metal Applicator Gun (for Silicone Sealant)
Rubber Mallet
Wood Beating Block
Spacers, Shims and Wedges
Grout Float (Cement or Epoxy)
Cutting/Fitting of Finish Materials
Wet Saw (See Figure 8.13)
Ceramic Tile Cutter and Accessories
Measurement
Carpenter’s Level
Laser Level
Straight Edge (4′/1200 mm)
Clean-Up
Sponges and Towels
Water Bucket
Solvents (epoxy or silicones)
Safety Equipment
Safety Glasses
Rubber Gloves
Dust Mask/Respirator
Safety Belts and Harness
8.7 Installation Procedure for Finishes Using Thin Bed Adhesives
Functions of a Notched Trowel
Gauges the Proper Thickness of Adhesive
Provides Proper Configuration of Adhesive
Aids in Efficient Application of Adhesive
The notched steel trowel is the primary and most fundamentally critical installation tool for the thin bed method of installation. The proper thickness of the adhesive layer is dependent on the type and size of finish, the cladding and substrate bonding surface texture, and the configuration and tolerance from consistent tile or stone thickness. A “gauged” or “calibrated finish" is tile or stone with a consistent thickness and a specified tolerance for deviation. An “ungauged” cladding is not consistent in thickness. Even gauged tile and stone can experience thickness tolerances of up to 1/8" (3 mm).
Notched steel trowels are available in several sizes and configurations to control the thickness of the adhesive mortar. The configuration of the adhesive application is critical to the performance of the tile or stone installation. In addition to controlling the final thickness of adhesive, the notched configuration results in “ribbons” or “ribs” of adhesive separated by spaces that control bedding or setting of the finish into the adhesive. The spaces allow the ribs of adhesive to fold into one another to decrease the resistance to pressure required for proper contact, and provide a controlled method of filling all air voids while allowing for the escape of air parallel to the ribs. This function is critical in assuring full contact and coverage of adhesive, not only to ensure maximum bond strength, but also to eliminate air voids or channels, which can harbor or transport water.
Notch Chart
It is important to maintain the specified notch depth and configuration of notched steel trowels throughout the project. The angle of the trowel during application of the mortar can have a significant effect on the height of adhesive ribs, which in turn can affect the height to width ratio (of the mortar “ribs”) which is necessary for the control of mortar thickness and elimination of air voids. Therefore, it is recommended to prohibit the common use of severely worn trowels and to require frequent trowel cleaning, and specification of trowel angle during installation as part of the quality control measures. A flat steel trowel is a tool used in applying an initial thin layer of adhesive in positive contact with both the bonding surface of the tile/stone, also known as back-buttering, and the surface of the substrate. The opposite side of a notched trowel typically has a flat edge for this purpose. A rubber mallet, wood beating block, or hard rubber grout float (for smaller tiles) can be used to beat-in the tiles after they are placed to help assure full contact with the adhesive, and minimize voids in the adhesive layer (Figure 8.19).
Thin Bed Installatin Procedure
The following is an abbreviated step by step process for the application of thin bed adhesive mortars. Follow the explicit manufacturer installation instructions for detailed information. For full installation specifications of thin bed, thick bed and membrane instructions– see section 10.
1. Apply a thin skim coat (1/16" [1.5 mm]) of thin-set or epoxy adhesive to the properly prepared dampened substrate with the flat side of the trowel; ensure good contact by scratching the edge of the trowel against the surface.
2. Additional thin-set or epoxy adhesive is then applied with the notched side of the trowel. Comb the mortar on the wall with the notched trowel holding it as close as possible to a 90° angle to the substrate. This will ensure the proper size of notches.
3. The ribs of thin-set or epoxy adhesive should be troweled in one direction only, and not in a swirl pattern. If additional thickness of adhesive is needed, add to the back of the finish using the same procedure as on the substrate, making sure that the direction of the combed mortar is identical to the one on the substrate, otherwise, you will end up with notches in two directions that disturb each other and consequently will not allow full contact between the mortar and the back of the tile/stone.
4. As a rule of thumb, tile/stone sizes larger than 8" x 8" (200 x 200 mm) should be back buttered. Back buttering not only improves the contact between the mortar and the back of the tile/stone, but also helps to ensure complete coverage. Another important consideration for back buttering is that if the tile/stone are not fully bedded by proper beat-in, the ribs of thin-set or epoxy adhesive, which are not flattened, are being sealed by the coat applied to the back of the tile/stone.
5. The tile/stone should be pressed into place, and either twisted and pressed into position, or for tile/stone sizes 12" x 12" (300 x 300 mm) and greater, slid into position with a back and forth motion perpendicular to the direction of the thin-set or epoxy adhesive ribs.
6. The final step is to beat-in with a rubber mallet to ensure thin-set or epoxy adhesive contact and make the surface level with adjacent tile/stone.
8.8 Grout and Sealant Materials, Selection, Methods and Equipment
Purpose of Grout or Sealant Joints
The joints or spaces between pieces of tile/stone serve several important purposes. Aesthetically, joints serve as a design element, primarily to lend a pleasing scale with any size tile/stone module. Functionally, joints minimize water infiltration, and compensate for manufacturing dimensional tolerances of the tile/stone. More importantly, though, joints lock the tile/stone into place and provide protection against various delaminating (shear) forces. Depending on the joint material, a joint may also act to dissipate shear stress caused by movement.
Compensate for Tile Thickness Tolerances
The joints between tile/stone compensate for allowable manufacturing or fabrication tolerances, so that consistent dimensions (from center to center of joints or full panel dimensions) can be maintained. As a result, joints must be wide enough to allow variations in the joint width to accommodate manufacturing or fabrication tolerances in the tile/stone without being evident.
Minimize Water Infiltration
Filled joints between tile/stone allow most surface water to be shed. This helps prevent infiltration of water, which can lead to saturation of the setting bed and substrate, freeze/thaw damage, strength loss, and efflorescence. Depending on the grout or sealant material used, and the quality of installation, no grout or tile/stone will be 100% effective against water penetration, so there may always be a small amount of water infiltration by capillary absorption. Therefore, the use of a waterproofing membrane is strongly recommended in mass transit applications exposed to water.
Dissipate Movement Stress
Probably the most important function of grout or sealant joints is to provide stress resistance and stress relief. The composite locking action with the adhesive layer allows the tile/stone finish to better resist shear and tensile stresses. Joints serve to provide stress relief of thermal and moisture movement that could cause delamination or bond failure if the edges of the tiles were butted tightly. Further isolation of movement is handled by separating sections of tile/stone with movement joints (see Section 2.1 – Movement Joints and Section 10 – Movement Joint Specifications and Details). This ensures that the grout or sealant joint will always fail first by relieving unusual compressive stress from expansion before it can overstress the tile/stone finish or adhesive interface. The dissipation of stress provides additional safety factor against dangerous delamination or bond failure.
Grout Installation Procedure
The following is an abbreviated step by step process for the installation of grout. Follow the explicit manufacturer installation instructions for detailed information. For full grout installation specifications – see Section 10.
1. Prior to grouting, it is essential to conduct a job site test panel (preferably as part of the pre-construction quality assurance procedures) to test the grouting installation and clean-up procedures under actual job site conditions. During this test, you may determine the need to apply a grout release or sealer to the tile/stone prior to grouting in order to aid in clean-up and prevent pigment stain and absorption of cement paste (especially latex cement or epoxy liquids) into the pores of the tile/stone. This test may also determine if additional adjustments are necessary, such as saturation of the finish with water to reduce temperature, lower absorption, and aid in installation and cleaning.
2. Wait a minimum of 24 hours after installation of tile/stone before grouting.
3. Before commencing with grouting, remove all temporary spacers or wedges and rake any loose excess adhesive mortar from joints. Remove any hardened thin-set or epoxy adhesive which is above half the depth of the tile/stone. Insert a temporary filler material (rope, foam rod) into the movement joints to protect from filling with hard grout material. Wipe the tile/stone surface with a sponge or towel dampened with water to remove dirt and to aid in cleanup.
4. Apply the grout joint material with a rubber grout float, making sure to pack joints full.
5. Remove excess grout by squeegee action with the edge of the rubber grout float diagonal to the joints to prevent pulling of grout from the joints.
6. Allow grout to take an initial set, and then follow the appropriate clean-up process for the specific grout type used as stated in the manufacturer's written installation instructions.
7. Any remaining weakened grout haze or film should be removed within 24 hours using a damp sponge or towel. Temperature and grout type may require final cleaning sooner than 24 hours.
Silicone or Urethane Sealant
Installation procedures for sealant joint filler products are the same as for movement joints (see Section 2.1 – Movement Joints and Section 10 – Expansion Joint Specification and Details).
8.9 Post Installation Cleaning
Most clean-up should occur during the progress of the installation, for hardened adhesive and grout joint residue may require considerably more aggressive mechanical or chemical removal methods than required while still relatively fresh. Water based cement and latex cement adhesives clean easily with water while fresh, or may require minor scrubbing or careful scraping together with water within the first day. Epoxy and silicone adhesives and joint sealants may require more aggressive scrubbing techniques and chemicals if residue is greater than 24 hours in age.
8.10 Mechanical Means and Methods
As an alternative to the common traditional means and methods of installation, mass transit applications lend themselves to the use of mechanized means and methods due to the size and uniqueness of the application. In many cases, mechanized equipment can greatly improve productivity while lowering labor and installation costs. Generally, the set up and clean up time of the equipment factors into the decision whether to use the mechanized equipment. The following sections provide an alternative to the traditional means that are typically used in most ceramic tile/stone installations.
Power Screeds
Power screeds are used as an alternative to the conventional wood or aluminum straight edges methods of leveling and “pulling” of mortar beds. The power screeds run on small electric powered or gas powered engines which vibrate to help facilitate the screeding of the mortar bed. The power screed sits on aluminum ribbons which are set to the desired height. The power screed is pulled over the ribbons to compact and level the mortar bed faster and more efficiently than manual methods.
Power Grouting
Power grouting is accomplished by using a mechanized grout spreading machine. The grout is spread by using rubber blades mounted on a powered rotating machine. This equipment will spread both latex fortified portland cement based and epoxy grouts in an effective manner. These machines pack the joints and strike the excess grout from the face of the tiles in one step. The rubber blades can be changed when excessive wear is noticed. The mechanized power-grouting machine has interchangeable pads to easily convert to the clean-up process. Traditional methods and equipment will still need to be used in small areas where the use of the mechanized equipment becomes impractical.
Mortar Mixers and Pumps
Mortar mixers and pumps are used as an alternative to conventional mortar mixers. The pump and mixer apparatus effectively mixes and pumps the mortar through a 3" (75 mm) hose to the desired location. The strength and style of these machines varies greatly depending on the amount of mortar to be mixed, the distance to place the mortar, and the amount of mortar to be placed.
8.11 Renovations of Existing Mass Transit Facilities
Mass transit applications are expected to handle and stand up to demanding circumstances and situations, including 24 hour use, pedestrian and vehicular loads, as well as vibration and other loads that emanate from these facilities. In many cases, renovations of existing facilities are required when finishes experience wear, damage, falling out of code compliance, or just become outdated. Due to unique performance characteristics, tile and stone is used on a frequent basis to repair and renovate existing mass transit facilities.
Most if not all of the same principles that govern new installations of tile/stone apply to renovation applications. Section 10 includes various renovation options including details that depict new tile or stone installed over existing tile, stone, terrazzo, and other existing finish types. The versatility of tile and stone makes it a great choice for use in restoration projects. Provided that existing substrates are sound, well adhered and properly prepared, a restoration solution exists for the application. Suitable existing substrates include; concrete, terrazzo, existing ceramic tile and stone, resilient flooring and non-water soluble cut-back adhesive. The various high strength tile/stone adhesive types and installation accessories, including the use of anti-fracture and waterproofing products provide solutions for these demanding applications. In addition, rapid setting adhesives, membranes and grouting products can return newly renovated areas back to service in a relatively short period of time.