Section 12 – Troubleshooting and Case Study

Section 12 – Troubleshooting and Case Study

This section will cover some of the most common installation issues and pitfalls surrounding swimming pool, fountain and spa applications. In contrast, the case study will highlight and stress the critical aspects of a tile or stone installation in wet area applications.

12.1 Troubleshooting Pictorial

Figure 12.1 – Exterior applications must be protected from the elements during the installation and installation materials cure periods. A temporary tent was erected over this swimming pool to protect the application from direct sunlight, wind and rain.

Figure 12.2 – Effects of exposure to rain prior to the waterproofing membrane reaching its full cure. This damaged waterproofing membrane will need to be removed, reinstalled, protected and allowed to reach its full cure.

Figure 12.3 – Once the waterproofing membrane is applied, it should be protected from traffic and work from other trades.

Figure 12.4 – The liquid applied waterproofing membrane must be flashed into a two part clamping style drain to create a watertight seal.

Figure 12.5 – Steel pool tank. Porcelain mosaic tiles are installed with a 100% solids epoxy thin set mortar adhesive (e.g. LATAPOXY® 300 Epoxy Adhesive) to achieve a suitable bond to the steel tank assembly.

Figure 12.6 – The increased use of prefabricated tubs (e.g. fiberglass or stainless steel) requires the use of a 100% solids epoxy adhesive (e.g. LATAPOXY 300 Adhesive). In this instance, a typical latex fortified portland cement based thin set mortar was used over a fiberglass tub that resulted in bond failure.

Figure 12.7 – Porcelain mosaic tiles installed on pool deck. Notice the ribbons of latex fortified thin set mortar combed in one direction to maximize coverage.

Figure 12.8 – Only enough latex fortified portland cement thin set mortar is spread to allow the installation of the porcelain mosaics within the mortar’s typical open time – generally 15 minutes at 70°F (21°C).

Figure 12.9 – It is good practice to periodically lift / remove freshly installed tiles or stones to verify that a minimum 95% continuous adhesive mortar is achieved. If the desired coverage is not achieved, use a larger trowel to dispense adequate adhesive mortar and beat-in the tiles correctly to achieve the desired results.

Figure 12.10 – The effects of a mesh mounted glass tile utilizing an adhesive and mesh that are not suitable for continuous submersion. The adhesive has expanded and lost bond to the back of the tiles.

Figure 12.11 – Large PVC dots on rear/edge mounted
porcelain mosaic tiles can lead to bonding issues as is evidenced from these photos. Latex fortified portland cement based thin set mortars may have a difficult time achieving a sufficient bond to the PVC rubber. The PVC dots are covering 50 – 60% of the tile back. An epoxy adhesive may be required to install tile mounted in this fashion in wet area and continuous submersion applications.

Figure 12.12 – Sealant in the movement joint is missing. In order for the sealant to maintain its functional ability, the joint must be correctly designed. Namely:

1. The joint depth must be at least 1/2 the width of the joint. Therefore, if a joint is 1/2" (12 mm) wide, the joint depth must be at least 1/4" (6 mm).

2. Closed cell polyurethane backer rod should be used in joints with sufficient depth. The backer rod must fit neatly into the joint without compacting. Bond breaker tape can be used in joints that will not allow the use of backer rod.

3. Sealant primer is generally used in wet area applications. Use non-solvent based primers.

4. The sealant and primer must be suitable for wet area applications and must not bond to the backup materials.

5. Use a class 25 sealant. This is a sealant that can withstand an increase and decrease of +/-25% of joint width.

6. Joint flanks (tile edges) to which the sealant will bond, must be kept clean and dry.

7. According to the Tile Council of North America’s Movement Joints – Vertical and Horizontal Detail EJ-171, typical wet area movement joints should be spaced every 8 – 12' (2.6 – 4 m) in each direction and against all restraining surfaces. Movement joints that are 8' (2.6 m) on center should be a minimum of 3/8" (9 mm) wide and joints that 12' (4 m) on center should be a minimum of 1/2" (12 mm) wide.

Figure 12.13 – Efflorescence becomes apparent in this baptismal font once the water is drained. When the vessel is full of water, the efflorescence remains in solution and is not visible. However, upon draining the water, the soluble salts crystallize and manifests as efflorescence. Proper attention to negative side vapor retarder placement is critical in wet applications. The proper placement and use of a suitable vapor retarder behind the concrete wall assembly would have minimized this unsightly issue.

Figure 12.14 – Notice the difference in color between the tile and grout above the water line and below the water line. This condition is typical because cement-based grout absorbs water and creates the darker look at the water line. Expectations should be managed accordingly.

Figure 12.15 – Erosion of grout joints is the diagnosis on this application. Possible causes are as follows:

1. Premature exposure to water or filling the vessel with water prior to the grout reaching its full cure (typically 14 days 70°F (21°C) if a latex fortified portland cement based grout is used or 10 days if an epoxy based grout is used.

2. Poor pool water maintenance. Improper balance of pool water pH, alkalinity and water hardness can all lead to this condition. Refer to section 11 for more information.

3. Edge mounted PVC dots that do not allow sufficient grout joint depth.

4. Insufficient packing of the joints during installation (e.g. bridging joints).

12.2 Case Study – Australian Pool Project

Case Study 1 – Concrete Pool Structure is being prepared to receive the tile finish. Examination of the concrete shell is made to evaluate and determine if leveling / preparation is required. The concrete shell is scheduled to receive a waterproofing membrane and subsequent porcelain tile finish. The concrete will require preparation prior to the installation of these materials. Notice the tile mechanic as he floats and shapes the contour of the pool utilizing templates, floats and screeds to achieve the desired form and height of the renders and mortar beds.

Case Study 2 – Mechanic is using a wooden template to shape and screed the swale in the water feature tank. Latex fortified portland cement mortars and renders are used for this purpose. Skilled mechanics determine and set finished tile heights, spots, and intersections using lasers, levels and site line builder’s transit levels.

Case Study 3 – The use of a LATICRETE® liquid latex fortified portland cement based leveling mortar is used to correct any irregularities in the concrete shell. Proper surface preparation will result in an aesthetically pleasing tile or stone finish.

Case Study 4 – Once the concrete shell is prepared, it is now ready to receive the waterproofing membrane. The leveling mortars are typically allowed to cure 48 to 72 hours at 70°F (21°C) prior to the installation of the waterproofing membrane. The penetrations, drains, lights, windows, pipes, etc…are prepared first. In this instance LATICRETE 9235 Waterproofing Membrane, the gold standard in waterproofing membranes for tile and stone installations, is being used. The liquid component and fabric is used to first treat these areas.

Case Study 5 – Coves, corners, and any changes of plane are also pretreated.

Case Study 6 – Movement joints are also included in the pre-treated areas. The waterproofing membrane is looped down into the movement joint (to accommodate any potential movement). The waterproofing membrane must be given enough “slack” when looped into the joint to accommodate the anticipated movement. The waterproofing membrane is then lapped onto the concrete / mortar bed joint flanks and horizontal areas by at least 2 – 4" (50 – 100 mm) to receive the main waterproofing membrane treatment.

Case Study 7 – Once the pre-treated areas are dry, the main membrane application can commence. Notice how the fabric component is pre-cut in order to be placed quickly into the freshly applied liquid component. Generally, the waterproofing membrane is overlapped by a minimum of 2" (50 mm) onto adjacent areas. A vacuum cleaner is used to ensure that the concrete is cleaned of any dust or debris prior to the application of the waterproofing membrane. The concrete is then dampened with a sponge and clean water in an effort to reduce the suction effect of the concrete and allow the membrane to remain workable for an extended period of time.

Case Study 8 – The waterproofing installation is complete. The waterproofing membrane must be allowed to fully cure prior to the flood test. Full cure rates will vary by product type. Consult with the waterproofing manufacturer for full details.

Case Study 9 – The penetrations are sealed with a suitable flexible sealant. Generally, 100% silicone sealant (e.g. LATICRETE® Latasil with LATICRETE 9118 Primer) or urethane sealant with non-solvent based primers can be used. All precautions to create a complete watertight tank must be taken to ensure a successful flood test.

Case Study 10 – The swimming pool is now in the flood test stage. The waterproofing membrane must be allowed to reach its full cure prior to flood testing. Full cure will vary by manufacturer and product type. The pool is filled at a rate of 1" (25 mm) per hour. Generally the water level will be continually monitored during the length of the flood test (typically 24 - 72 hours) to determine a vessel’s ’water-tightness’. The water is then drained at a rate of 1" (25 mm) per hour.

Case Study 11 – The tile installation can now begin. Generally, work begins on the vertical areas first. A high strength liquid latex fortified thin set mortar (e.g. LATICRETE 254 Platinum; or, LATICRETE 4237 Latex Additive mixed with LATICRETE 211 Powder) suitable for submerged applications is used. Care is required when working over the waterproofing membrane.

Case Study 12 – The installation of the tile in the horizontal areas is now complete. Once the tiles are installed and grouted; the installation must cure for a full 14 days after the final grouting period at 70°F (21°C) if a latex fortified portland cement based grout (e.g. LATICRETE PermaColor Grout) is used or 10 days if an epoxy based grout (e.g. LATICRETE SpectraLOCK® PRO Grout*) is used.

After the installation materials have fully cured, the water feature can be filled with water. Use the same water fill and drain rate of 1" (25 mm) per hour whenever a tiled water feature is filled and drained.

Case Study 13 – The pool in its finished state and ready for the crowds.

* United States Patent No.: 6881768 (and other Patents).