Grout for Travertine: Filled, Unfilled and Tumbled Tile

Grout travertine according to how its holes are treated. Filled and honed or polished travertine takes unsanded or fine high-performance grout in 1/16 to 1/8 inch joints. Unfilled and tumbled travertine takes sanded grout, which also fills surface holes in the same pass. Match grout to the stone's lightest common tone, seal first, and never use acid cleaners.

For how travertine relates to marble, limestone, slate and granite, see the natural stone overview. This page deals with what is unique to travertine: its holes.

Filled, unfilled and tumbled travertine

Travertine forms from calcium carbonate deposited by mineral springs. Gas bubbles and plant material leave voids, from pinholes to holes over 1/2 inch wide, sometimes connected beneath the surface. ASTM C1527 covers travertine as dimension stone. Commercially it is sold in a few distinct forms:

Factory filler is not permanent. On filled travertine, a few small holes are often open at delivery or open up within the first year as filler pops out under traffic. A grout pass is the normal way to refill them. Resin fillers can also show slight color differences from the stone; that is a product characteristic, not a grout fault.

Filling holes vs grouting joints

Grouting joints and filling holes involve the same material but different behavior. A joint is a narrow slot with stone on two sides and mortar at the bottom. A hole can be shallow and wide, or deep and connected to hidden cavities. Holes take grout in quantities that are hard to predict, and the grout in them shrinks and slumps more than in joints.

Should you fill the holes at all?

• Fill them on floors, showers, countertops and anywhere wet. Open holes trap dirt, soap and water, harbor mildew and can hold enough water to keep the stone dark and damp. In showers, filled holes are effectively required for a cleanable surface.
• Leaving them open is a design choice some people make on walls and fireplace surrounds for a rustic look. It is acceptable where nothing will be spilled or splashed. Open holes can always be filled later; filled holes are hard to empty.

Methods for filling travertine holes

1. Grout everything in one pass. Common for tumbled travertine. Float sanded grout diagonally, pressing hard across the face so holes fill along with the joints. Cleanup is slower because the whole face is covered.
2. Fill holes first, joints second. Useful on unfilled honed stone with many holes. Fill the holes with grout (or a stone filler) a day before grouting, let it firm, then grout the joints. This handles slumping and makes the joint pass faster.
3. Fill as a second pass. After the first grout pass cures enough to walk on (often 24 hours), look across the floor with a low light. Holes that slumped or show pinholes and voids get topped up with fresh grout pressed in with a small margin trowel or a gloved finger.

For holes deeper than about 1/2 inch, pack in layers. A single thick plug of cement grout can shrink and crack around its edges or sink below the surface. Color-matched epoxy or polyester stone fillers are options for occasional large holes on polished surfaces, but they cure shiny and can differ in color from grout.

Which grout type

Use joint width first, then finish. The general rules are in which grout do I need; the travertine-specific choices are:

• Tumbled and chiseled-edge travertine: sanded grout or a high-performance cement grout. Joints are wide and edges irregular, and the sand helps holes fill without shrinking as much. A tumbled face will not be scratched by sand.
• Filled honed travertine with tight joints: unsanded or a fine high-performance grout. Honed travertine can mark slightly if sanded grout is ground hard across it.
• Polished travertine: treat it like polished marble: unsanded or fine grout, with a scratch test. The marble grout guide covers the test procedure.
• Epoxy: excellent for stain resistance in kitchens and showers, but very difficult to clean out of the open texture of tumbled or unfilled travertine, and some epoxies can darken porous stone. Use it on filled, honed stone and only after testing.

Premixed and urethane grouts are workable on filled travertine. They are generally not designed to bulk-fill deep holes; check the product's maximum fill depth.

Grout color for travertine

Travertine is rarely one color. A typical ivory or beige tile includes cream, tan, gray-beige and occasional rust or walnut veins. Grout colors should match the lightest common tone, or the color of the existing factory filler, because filled holes become part of the face.

• Light travertines (ivory, classic): bone, almond, light beige or warm off-white. Pure white looks chalky.
• Walnut and noce travertines: tan, mocha or light brown, matched to the middle tone.
• Silver or gray travertines: warm gray or light gray, matched against a dry, sealed sample.

Grout dries lighter than it looks wet, and porous stone can change grout color by pulling water unevenly. See grout discoloration and shading for why blotchy grout occurs and the grout color guide for broader design choices.

Sealing travertine before grouting

Travertine is among the most absorbent stones commonly used indoors. Unsealed, it pulls water and pigment from the grout, causing dark joint borders and a hazy tint on the face. Grout residue also lodges in the stone's pores and is hard to remove from an unsealed surface.

• Apply a penetrating stone sealer to the face as a grout release after the tile is set and the mortar is firm, keeping it off the joint walls.
• On tumbled travertine, sealer on the rounded edges can get into the joint. Apply carefully with a small pad, or seal loose tiles on the face before setting.
• Let the sealer cure for the time the label specifies before grouting.
• Seal again after the grout has cured. Travertine and cement grout both benefit; see how to seal grout and how often to seal grout.

Acid sensitivity and cleanup

Travertine is calcite, so it etches in acid exactly as marble does. On honed and tumbled faces, etching shows as light, rough spots; on polished travertine it dulls the shine. Never use sulfamic or phosphoric acid haze removers, vinegar or citrus cleaners on travertine. Use non-acidic, stone-safe haze removers and neutral daily cleaners, as described in grout cleaners by pH.

Cleanup technique on textured travertine

• Tumbled and chiseled faces hold grout in every pit. Cleaning slightly earlier than usual helps, because grout left to firm in the texture is hard to remove. Test with a finger: the joint should resist light pressure.
• Use a well-wrung sponge and wipe diagonally. On tumbled stone, a soft nylon brush lifts grout from pits without pulling it out of filled holes.
• Do not chase every speck on the first pass. Final haze removal with a dry cloth or a stone-safe product the next day is easier than over-washing fresh grout, which weakens it. The routine is detailed in how to remove grout haze.