Bathroom Tile Installation

Tile is the visible part of bathroom work and the part homeowners choose. It is also the part least likely to be the reason a bathroom fails. What fails is the substrate, the waterproofing, or the movement joints, all of which are decided before a single tile is set.

Substrate: what tile is set on

Tile is rigid and brittle. It needs a base that is flat, stiff and appropriate to the location.

Floors need to resist deflection. If the floor flexes underfoot, tile cracks, usually in a straight line following a joist or a subfloor seam. In older houses around here, joists are often smaller and spanning further than modern practice would allow. Remedies are ordinary: an added plywood layer to stiffen and flatten, an uncoupling membrane to let the tile move independently of minor substrate movement, or sistering joists where deflection is genuinely excessive.

Wet walls need cement backer board or an equivalent, never drywall or greenboard. Greenboard is moisture-resistant paper-faced drywall; it belongs outside a shower, not inside one. Backer board is stable when wet but not waterproof, so it needs a membrane over or behind it.

Dry walls outside the shower can take tile over properly prepared drywall.

Flatness is measured, not eyeballed. Larger tiles demand a flatter plane, because any deviation shows up as lippage at the tile edges where the light rakes across them.

Waterproofing

Grout is porous and water passes through it. That is expected. The membrane behind the tile is what keeps water out of the structure. This is covered in full on the shower remodeling page, and the short version is: a continuous bonded membrane, detailed correctly at every corner, the curb, the niche and the drain, with components from a single system rather than mixed.

Tile materials

Porcelain

Dense, low absorption, hard-wearing. The default for bathroom floors and a perfectly good wall tile. Through-body porcelain has the same color throughout, so a chip is far less visible than on a glazed tile. Cuts cleanly with the right blade.

Ceramic

Softer and more absorbent than porcelain, and less expensive. Fine on walls. On a floor it will wear faster, and it is not the right choice in a shower floor.

Natural stone

Marble, limestone, travertine and slate all bring variation no manufactured tile matches. All are porous and need sealing, and marble in particular will etch from acidic products. Honed rather than polished is safer underfoot. Beautiful, and a genuine maintenance commitment.

Glass mosaic

Used as an accent band or a full feature wall. Installation is more demanding because the setting material shows through, so it needs a white thinset applied evenly. Cuts chip easily without the right blade.

Cement and encaustic

Handmade, with pattern running through the body rather than printed on the surface. Very porous and needs sealing before grouting as well as after, or the grout stains the tile permanently. Striking on a bathroom floor and not a low-maintenance choice.

Slip resistance

A bathroom floor and a shower floor have to be safe when wet and soapy. That is a real safety consideration rather than a technicality, particularly in a house with older residents or small children.

Look for a tile with a published coefficient of friction suitable for wet areas, or one with genuine surface texture. Small-format tile provides grip partly through the grout lines themselves, which is one reason mosaic has always been the traditional shower floor. Large-format tile on a shower floor is achievable with a linear drain, but choose one with texture. A polished tile that looks superb on a wall can be dangerous underfoot.

Layout and pattern

Where a pattern starts determines where the cuts land, and cuts are what people notice. Centering on a focal wall or a fixture means the cut tiles fall symmetrically at both ends rather than leaving a sliver on one side.

Running bond at half offset is traditional and, with tiles over about twelve inches long, prone to lippage because of the natural crown in the middle of a long tile. A one-third offset is what most manufacturers now recommend for that reason. Stacked or grid layouts are unforgiving of any wall that is out of plumb, because the grid makes it obvious. Herringbone and chevron look excellent and carry considerably more labor because every perimeter tile is an angled cut.

Grout and movement joints

Cement grout comes sanded for wider joints and unsanded for narrow ones, and it should be sealed. Epoxy grout resists staining and water far better and is harder to install, which is why it costs more; in a shower floor it is often worth it.

Joint width is dictated by the tile. Rectified tiles with machined edges can take a narrow joint. Handmade tile needs a wider one to absorb its own variation.

Movement joints are the part most often got wrong. Anywhere the tile meets a different plane or a different material (wall to floor, inside corners, around a tub, at the perimeter of a floor) needs flexible sealant rather than grout. Buildings move with temperature and humidity, grout does not, and grout in those joints will crack. Matching sealant is available for essentially every grout color, so it does not have to look like a compromise.

Where tile falls in the sequence

After rough plumbing and electrical have passed inspection, after the substrate is prepared and the waterproofing is installed and tested. Before vanities, fixtures and glass, because those are fitted to the finished tile surface.

Cure times between setting, grouting and using the shower are real. Thinset needs to reach strength before grout goes over it; grouting too early traps moisture in the bed. Sealing waits until the grout has cured. This is a few days of doing nothing, and skipping it causes problems that show up months later.

What drives tile cost

• Area covered, and particularly whether walls go to the ceiling.
• Tile price per square foot, which ranges from a few dollars to a great deal more.
• Format. Mosaic is far more labor per square foot than large-format; large-format needs more substrate preparation.
• Pattern. Herringbone and chevron roughly double the setting labor of a running bond.
• Substrate preparation, which in an older house is often the biggest hidden line.
• Waterproofing system.
• Grout type, with epoxy costing more in material and labor.
• Trim and edge detail, especially mitered edges and specialty profiles.

Tile work across our service area

Substrate conditions differ a lot by era of house. We tile bathrooms in Maplewood, South Orange, Bloomfield, Springfield and across our service area. Back to bathroom remodeling.

Every town has its own bathroom remodeling page covering the housing there and what it means for a project. See the full service area.