Specification

FAQ: INSTALLING TILE ON

WALLS AND OVERHEAD

With the size growth of today’s tiles, installations on vertical surfaces and ceilings adds extra challenges involving deﬂection

and gravity to a project. Here are some of the most commonly asked questions about how to successfully install tile on walls

and overhead, whether indoors and out.

WHAT CAN BE INSTALLED AND WHERE

Question: What is the maximum tile size and weight that can be installed on walls?

Answer: For direct bond installation on commercial projects, the 2012-2020 International Building Code limited tile on

exterior walls to less than 24" long on any side, less than 3 square feet in total area and less than 9 lbs. per

square foot (43.9 kg/m

) in weight.

The new 2021 International Building Code allows tile on exterior walls as follows: Section 1404.10.2 Exterior

adhered masonry veneers-porcelain tile. Adhered units weighing more than 3.5 lbs. per square foot (0.17 kN/M

)

shall not exceed 48 inches (1219 mm) in any face dimension nor more than 9 square feet (0.8 m

) in total face area

and shall not weigh more than 6 lbs. per square foot (0.29 kN/M2). Adhered units weighing less than or equal to

3.5 lbs. per square foot (0.17 kN/M

) shall not exceed 72 inches (1829 mm) in any face dimension nor more than

17.5 square feet (1.6 m

) in total face area. Porcelain tile shall be adhered to an approved backing system.

Section 1404.10.3 Interior adhered masonry veneers. Interior adhered masonry veneers shall have a maximum

weight of 20 lbs. per square foot (0.958 kg/m

) and shall be installed in accordance with TMS 402, section

12.1 and 12.3. Where the interior veneer is supported by wood construction, the supporting members shall be

designed to limit deﬂection to 1/600 of the span of the supporting members. TMS 402 and 602 can be

acquired from The Masonry Society.

For porcelain tile there are no speciﬁc restrictions for interior walls, but some suggest that maximum weight

should not exceed 15 lbs. per square foot. Larger and heavier tiles will require anchoring with mechanical

fasteners. Be sure to consult your local building code or other authorities having jurisdiction for tile size and

weight limits on your speciﬁc project and follow framing and wall board manufacturer’s recommendations.

Question: Is gypsum drywall a suitable substrate for tile installation?

Answer:

International Building Code restricts the use of gypsum drywall, including water-resistant gypsum drywall, in wet

areas such as showers and tub surrounds. In these applications, a cement backerboard such WonderBoard

Lite should be installed. Bare gypsum drywall is a suitable substrate for dry, interior applications.

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FAQ: INSTALLING TILE ON WALLS AND OVERHEAD With the size growth of today’s tiles, installations on vertical surfaces and ceilings adds extra challenges involving deflection and gravity to a project. Here are some of the most commonly asked questions about how to successfully install tile on walls and overhead, whether indoors and out.
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Question: Can tile be directly installed to wood surfaces or foam insulation? Answer: No. Plywood and OSB are not suitable surfaces for installing tile on walls and foam does not have the tensile strength to support tile. WonderBoard Lite cement backerboard or lath and a cement scratch coat must be installed to the wood or foam surface before the installation of tile with an appropriate mortar.
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Question: What kind of mortar should be used to set tile on walls and ceilings? Answer: When tiling vertical or suspended surfaces, it is important to use a mortar that has excellent non-sag qualities. These mortars are designated by ANSI with the letter “T” after the standards number. ProLite® Premium Large Format Tile Mortar that exceeds the requirements of ANSI A118.15T and is formulated to support the weight of large and heavy tiles on walls.