Ceramic Tile Problems

Ceramic Tile Problems

Ceramic Tile Problems:

Lippage is how level the tiles are in relationship to the neighboring tiles. If the tiles are not level it could mean the sub-floor is not level or there is debris under the tile, the tile was not set properly in the mortar, or the tiles were manufactured at varying thicknesses.

Cracked or loose tiles, chipping and splitting is a sign of installation errors, excessive expansion, sub-floor or structural problems.

Crazing is tiny fissures in the glaze caused by the tiles being cooled to quickly after they were fired in the kiln. Tiles with visible crazing should not be installed. Crazing is a manufacturing defect.

Grout Problems:

Shading or Mottling – The most common grout problem is color and shading variations. To some degree shade variation is unavoidable due to the nature of the grouting process. Extreme color and shade variations are mainly due to uneven drying and hydration of the grout. Other common causes are too much water used during clean up, uneven grout depth, highly absorbent tiles and the use of different batches of grout. To prepare grout for coloring use a neutral pH cleaner.
Stains – Older grout typically stains because of normal use. Stained and soiled grout joints are unsightly but great candidates for the coloring process. Grease, oil, sealers, paint, dirt and dust are bond breakers for grout colorants and will color unevenly when penetrating stains are used. If possible, determine what contaminants caused the stain so that the appropriate cleaning method can be used.
Exposed Silica Particles – Sanded grout is made of two materials called surface fines and silica sand. Surface fines are small fine grains of the Portland cement that form the visible surface layer of the grout. Surface fines give grout its smooth finish and contain the grout color. Silica sand is comprised of larger particles of aggregate or inert filler, which give strength to the body of the grout. When using to much water during installation clean up, harsh acid or alkaline cleaners, and age can remove the surface fines revealing the silica sand beneath. The silica sand will look like gray or brownish spots often mistaken as stains. These areas of the grout will have a rougher texture than the surrounding grout. Topical colorants will not adhere silica sand because of the physical properties of the silica sand, and penetrating stains will not mask these areas. Replacing the affected grout is necessary before the grout can be colored.
Efflorescence is caused by soluble salts in the grout, mortar bed or concrete slab are often brought to the surface during the drying process by moisture migration. These mineral salts appear on the surface of the grout as a white crystalline powder substance. This is known as efflorescence and can be caused by excess water in the grout or setting materials. Coloring the grout will not stop this process. The efflorescence must be allowed to run its course and then be properly cleaned before coloring can proceed.
• Powdery Grout Joints – Powdery grout joints are sometimes the result of improper curing of the grout joints. Hot or dry weather, highly absorbant tile and improper grout mixing can cause the water in the grout to evaporate too quickly stopping the hydration process necessary for the grout to harden. Powdery grout joints can only be repaired by replacement.

Cracking – Improper curing of the grout, deflection in the substrate or improperly mixed grout can cause cracking of the grout joints. Colorants, enhancers and stains take the shape of the grout joints and will not cover or fill the cracks. Cracked joints must be removed and re-grouted.

Slip Resistance: There is a test for slip resistance ASTM C-1028 under the American National Standards for Ceramic Tile (ANSI) A137.1. Typically the test is done in the laboratory however under special circumstances it may be possible to do in the field. An experienced technician is key to accurate results. There are other tests but they are not part of the standard. There is no National requirement for slip resistance , only the recommendation of OSHA and ADA that areas of egress are slip resistant.

Linda Lockwood
Statewide Floor Covering Inspection Service


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