Twelve-inch square tiles no longer reign supreme. Tile sizes have increased and now 12-inch by 24-inch tiles and 48-inch-long planks are the norm.
There is a misconception that these larger tile sizes do not affect the methods or equipment needed for installation, when in fact more planning is required to ensure it goes smoothly. Other myths prevail, eight of which are debunked here.
Myth 1: Large Format Tiles are Only the Really Big Ones
Large format tiles are not just 24-inch by 48-inch. They include all tiles with at least one edge that is 15 inches. This means those six-inch by 48-inch wood-look plank tiles are considered large format. Mortar specifically made for large format tile should be used to ensure proper coverage.
Myth 2: The Substrate Doesn’t Need to be that Flat if More Mortar is Used
The American National Standards Institute requires a flatter surface for large format tiles than smaller ones. The flatness requirements dictate that the substrate should not vary by more than an 1/8-inch in 10 feet, and no more than 1/16-inch in 24 inches. Patches or self-levellers can help achieve this flatness.
Myth 3: A Small Square Notch Trowel will Work Just Fine
There is no one-size-fits-all guideline for trowels for large format tile applications but 80 to 100 per cent mortar coverage should be achieved to ensure proper coverage, depending on installation area and tile type. A 1/4-inch by 1/4-inch square notch trowel will not attain adequate coverage for large format tile. Consider a 1/2-inch by 1/2-inch square notch trowel, a Euro notch trowel or a slant notch trowel to reach sufficient mortar coverage.
Myth 4: Large Format Tiles Should be Offset 50 Per Cent
If tiles are offset by 50 per cent, the highest part of one tile will be next to the lowest part of the next. This can potentially cause a trip hazard. The Tile Council of North America recommends a maximum of 33 per cent offset for large format tiles.
Myth 5: Moisture Mitigation is a Waste of Money
High moisture in the slab coupled with fewer grout joints for the moisture to escape increases the chance of efflorescence. Moisture mitigation below the tile installation can protect it from the moisture in the concrete.
Myth 6: Bigger Tiles mean a Faster Installation
While less tiles are set when using larger formats, a lot of work must be done in advance of them being laid. Adequate surface preparation, cuts to accommodate plumbing, transportation of the tiles, back-buttering and additional care to set the tiles in place all takes sufficient time. Make sure to account for this increased labour in the bid.
Myth 7: Special Equipment is Not Needed
When working with large format tiles, especially gauged porcelain panels, additional equipment is needed — angle grinders to cut around plumbing, sturdy tables to support the tiles, suction cups to lift the panels and a system of levelling clips.
Myth 8: All Large Format Tiles are the Same
Large format tiles encompass quite a few tile types, including large format natural stone and gauged porcelain panels. Because of this, it is important to know exactly what type of tile is being installed in order to select the right mortar for a successful installation.
Emily Brunner is an area technical manager at TEC Installation Systems, which provides floor preparation and installation products for tile, stone, wood, carpet and resilient flooring. TEC products are available throughout Canada.