How to Glue Down Luxury Vinyl Tile

Why this matters

Glue-down luxury vinyl tile is thin, flexible and honest: it shows everything underneath it. A patch ridge, a plywood seam, a trowel line from the adhesive, a grain of grit: all of it telegraphs through within days, and in a kitchen with a window at one end, the low morning light finds every one. The other two ways it fails are quieter: tile set into adhesive that had not flashed, or flashed too long, and tile that was never rolled, both of which leave edges that lift and joints that open. All three are decided before the last tile goes down.

Start state: what you need and what to check

• The adhesive maker's data sheet and the flooring maker's instructions. They name the adhesive type, the trowel notch, flash and working time, the roller weight and the temperature range for the room, the tile and the adhesive.
• A substrate that is flat and smooth. Flatness is one number, owned by Floor Flatness Tolerances by Floor Type. Smoothness is the resilient-specific part: no ridges, no open seams, no nail heads, no texture you can feel through a sheet of paper. On wood that usually means underlayment panels (see related: How to Install Plywood Underlayment for Resilient Flooring); on concrete, patching (see related: How to Grind Highs and Patch Lows Before a New Floor).
• Moisture within the flooring and adhesive maker's limits on a slab, tested by ASTM F2170 or ASTM F1869 as the sheets name. See related: Slab Moisture Testing for Flooring.
• The old floor dealt with. Any resilient floor or black adhesive of unknown age is presumed to contain asbestos until tested; see related: Asbestos in Old Resilient Floors and Adhesive, and Nine-Inch Floor Tile and Black Mastic.
• Tile from several cartons, the notched trowel the sheet names (new, or one you have checked), chalk line, tape, utility knife, and the roller.

Step 1: Prep and patch to resilient smoothness

Fill seams, fastener heads, gouges and low spots with the patch the adhesive maker accepts. Feather each patch out so it has no edge, let it cure per its sheet, then knock down ridges with a pole sander or scraper. Sweep and vacuum, then wipe the hand across the floor. Anything you feel, the tile will show.

Hazard: cementitious patch contains crystalline silica in its sand. Mixing the powder and sanding cured patch both put it in the air; mix with the bag opened low and away from your face, sand with a vacuum-attached sander, and see related: Respirable Crystalline Silica and the Construction Standard for the controls 29 CFR 1926.1153 requires.

What breaks if skipped: telegraphing, and it cannot be fixed without pulling tile.

Step 2: Snap center lines and balance the borders

Tile is laid off lines through the middle of the room, not off a wall, so the borders come out even on both sides and the pattern stays square to the room's center even when the walls are not.

1. Find the midpoint of each pair of opposite walls and snap a line between the midpoints: line A one way, line B the other.
2. Check square where they cross with a 6-8-10 triangle: 6 ft along one line, 8 ft along the other, and the diagonal between those marks must read 10 ft. Adjust line B until it does.
3. Dry-lay a row of tile from the crossing to each wall along both lines. If any border cut comes out under half a tile, shift that line by half a tile and re-check.

Step 3: Spread with the adhesive maker's notch

Spread one section at a time, working from the line out and from the far side of the room back toward the door so nobody walks on wet adhesive to get out. Hold the trowel at the angle the sheet shows and stay just shy of the chalk line so it stays visible.

Check the notch. A trowel loses notch depth as it wears on concrete or patch, and a shallow notch starves the tile. Compare it to the profile on the sheet before each job and swap it when the teeth have rounded.

Step 4: Observe the flash time

Pressure-sensitive adhesive (PSA) is spread wet and left to flash, meaning the water evaporates until the film turns from milky to clear and is tacky but does not transfer to a light fingertip touch. Tile set before it flashes sits in wet adhesive, slides, and can squeeze adhesive up through the joints. Tile set long after the working time ends has nothing to grip. The sheet gives both times for stated conditions; cold rooms and humid air slow the flash, so the touch test decides, not the clock.

Some adhesives are also allowed as wet-set for heavy rolling loads; that is a different procedure with its own time window, and the sheet says when to use it.

Step 5: Set the tile to the lines

Set the first tile exactly in the corner of the line crossing, then build outward in a stair-step so every new tile is guided by two placed edges. Set each tile down flat into place rather than sliding it into the adhesive. Close the joints tight without compressing the tile edge. Mix tiles from several cartons as you go so shade variation scatters.

Kneel on a kneeling board on set tile, not on open adhesive.

Step 6: Roll both directions with the heavy roller

Roll each section with the roller weight the flooring or adhesive maker names (commonly a three-section roller in the 75 to 100 lb range), first one direction, then across at 90 degrees, within the time the sheet states. A hand roller does the edges and corners the big roller cannot reach. Many sheets call for a second roll later; do it when the sheet says.

Why: PSA bonds by pressure. An unrolled tile is stuck at the high points of its back only.

Hazard: a 100 lb roller pulled backward is a trip-and-fall over the room's edges and doorways; push it, and get help lifting it into and out of the truck.

Worked example: a 15 by 12 kitchen

The room measures 180 inches east to west and 144 inches north to south, with the door at the east end of the south wall. Tiles are 12 by 24 inches, set with the long side east to west. The slab tested inside both makers' limits.

Balancing east to west (line B, north to south): centered, line B leaves 90 inches each side. 90 divided by 24 is 3 full tiles (72 inches) with 18 inches left, a three-quarter tile border at both end walls. Keep it.

Balancing north to south (line A, east to west): centered, line A leaves 72 inches each side. 72 divided by 12 is exactly 6 full tiles with nothing left, which sounds perfect and is not: walls are never exactly where the tape says, so the borders come out as slivers from 0 to 1/2 inch that cannot be cut cleanly. Shift line A north by half a tile, 6 inches. The north side becomes 72 minus 6 = 66 inches, 5 full tiles plus a 6 inch border; the south side becomes 72 plus 6 = 78 inches, 6 full tiles plus a 6 inch border. Half-tile borders on both walls. Check: 66 plus 78 = 144.

 PLAN, kitchen 180 in E-W by 144 in N-S
                   N wall
 +----------------------+----------------------+
 |  1: spread first     |  2: spread second    |
 |  66 in deep          |                      |
 +------- line A, E-W --+----------------------+
 |  3: third            |  4: last, out the    |
 |  78 in deep          |     door             |
 +----------------------+---------+ door +-----+
       90 in         line B         90 in
                    N-S, centered

Section sizes: north quadrants 66 by 90 inches, 5.5 by 7.5 ft, 41.25 sq ft each; south quadrants 78 by 90 inches, 6.5 by 7.5 ft, 48.75 sq ft each. Total 2 x 41.25 + 2 x 48.75 = 180 sq ft, the room's area.

What happened: quadrants 1 and 2 flashed in about the time the sheet stated at the room's 70 F and set cleanly. When the installer lifted a tile in quadrant 3 a few minutes after setting it, the back showed adhesive in stripes with bare lines between, not the even coat quadrants 1 and 2 had shown. The trowel had worn on the patched slab. A new trowel went on for quadrant 4, and the striped tiles in quadrant 3 were lifted, the adhesive re-spread with the new trowel, flashed, and the tiles reset. Rolled both directions, then rolled again at the time the sheet called for.

How to verify you got this right

Judge it standing, in normal light, the way the customer will see it, not with a flashlight laid on the floor.

• No telegraphing. Walk the room looking across the floor toward the window. No ridge lines, no seam lines, no dimples. In the kitchen the only mark found was a single grit bump in quadrant 2, which meant lifting and resetting that one tile.
• Full transfer. At least one tile lifted per section during the install showed full, even adhesive coverage on its back, quadrant 3's re-spread included.
• Tight joints. No gaps, no adhesive in the joints, no edges that catch a fingernail.
• Borders even. The 18 inch and 6 inch borders read the same at both ends of each wall, within what the wall's own wander allows.
• Edges down. Run a hand along the perimeter and the doorway: no lifting corners.

What changes the call

• Rolling loads or heavy commercial traffic often move the sheet to wet-set or a different adhesive entirely. See related: Commercial Flooring: What Changes From Residential.
• Tile with a click profile is not glued at all unless the sheet allows a glue-assist; it is a floating floor.
• Sun through glass. Many resilient products restrict direct sun or high temperatures; read the sheet before you agree to a sunroom.

References

• The adhesive maker's data sheet and the flooring maker's installation instructions (notch, flash and working time, roller, temperature)
• ASTM F2170 and ASTM F1869, slab moisture testing, as named by the makers
• 29 CFR 1926.1153, respirable crystalline silica in construction
• See related: Trowel Notches, Open Time and Adhesive Transfer
• See related: Floor Flatness Tolerances by Floor Type