Tiling defects in new homes — how to identify them, what's acceptable, and how to claim

Tiling defects are one of the most common complaints homeowners raise after taking possession of a new home, and they are also one of the most contested — because what constitutes a “defect” in tiling versus normal variation is not always obvious. Knowing the standards that apply and how to document what you find is the difference between a successful claim and an argument that goes nowhere.

The applicable standard: AS 3958.1

In Australia, tiling work in residential buildings is governed by Australian Standard AS 3958.1 — Ceramic tiles: Guide to the installation of ceramic tiles. This standard specifies acceptable practices for tile installation, including adhesive coverage, grout width, and dimensional tolerances. Where tiling work deviates materially from AS 3958.1, it is generally considered a building defect.

In the UK, the relevant standard is BS 5385 (Wall and floor tiling). In the US, the Tile Council of North America (TCNA) Handbook sets installation standards.

Hollow tiles (debonded tiles)

The most significant and most common tiling defect is debonding — where tiles have partially or fully separated from their adhesive bed and produce a hollow sound when tapped.

How to identify hollow tiles:

• Tap each tile firmly with a coin, knuckle, or the handle of a screwdriver
• A solid tile produces a dense thud; a hollow tile produces a hollow, ringing sound
• Mark suspected hollow tiles with a washable marker or sticky note as you go

What causes debonding:

• Insufficient adhesive coverage (AS 3958.1 specifies minimum 80% coverage for most applications, 95% for wet areas and external applications)
• Use of incorrect or expired adhesive
• Failure to back-butter large-format tiles
• Laying tiles over a substrate that was not adequately prepared or primed
• Movement in the substrate (differential settlement, thermal expansion) where no movement joints were provided

Hollow tiles are a recognised defect under Australian building standards. If a significant proportion of tiles in a room (typically more than a handful) are hollow, you are entitled to have the affected tiles removed and re-laid with correct adhesive coverage.

Single isolated hollow tiles in a large area may be accepted depending on context. A bathroom where 30% of floor tiles are hollow is clearly defective. One hollow tile in a kitchen floor of 100 tiles is in a different category.

Tile lippage

Lippage is the edge-to-edge height difference between adjacent tiles. Excessive lippage creates a trip hazard on floor tiles, affects the visual quality of wall tiles, and indicates incorrect installation.

AS 3958.1 and most builder specifications set a maximum lippage tolerance. Acceptable lippage depends on the tile size and the grout joint width:

• For floor tiles with a standard grout joint (3 mm or more): maximum 1 mm lippage
• For tiles with a tight joint (less than 3 mm): maximum 0.5 mm
• For rectified tiles (precisely cut to tight tolerances): maximum 0.5 mm regardless of joint width

Lippage is measured with a straight-edge placed across the joint between two tiles, then measuring the height difference with feeler gauges or a depth gauge.

Causes of excessive lippage:

• Tiles of uneven thickness (common with non-rectified tiles)
• Incorrect setting out (the tiler failed to account for tolerance variation between tiles)
• Uneven substrate
• Using tiles with warped backs without adequate compensation in the adhesive bed

If lippage exceeds the applicable tolerance in a significant proportion of tile junctions, rectification is warranted.

Cracked tiles

A cracked tile in a new build is always a defect unless it can be directly attributed to impact damage after handover. Cracking patterns include:

• Surface crazing — a fine network of cracks in the tile glaze; can occur in certain glazed tile types but is unusual in quality modern tiles
• Through-cracks — cracks that penetrate the full thickness of the tile; always a defect
• Corner breaks — chips or breaks at tile corners, often from incorrect cutting technique or impact
• Stress cracking — cracking along multiple tiles in a pattern suggesting movement in the substrate below

Photograph every cracked tile with the crack clearly visible and a ruler beside it for scale. Note the location (room, position in the room) and include the date.

Incorrect grout

Grout failures are a common post-occupancy complaint:

• Cracked grout — grout cracking within the first few months of occupancy usually indicates movement in the substrate, incorrect grout type, or the grout being applied before the adhesive was fully set
• Stained or discoloured grout at installation — indicates contamination during the grouting process or an incorrect grout mix
• Missing grout (grout joints not fully filled) — a workmanship defect
• Wrong grout colour — the installed grout does not match the specified colour; check your colour selection documents

There is an important distinction between grout joints and movement joints (control joints). Grout is not a movement joint. If a tile installation requires movement joints (for example, at the junction of different substrates, at re-entrant corners, or at regular intervals in large floor areas), these must be provided with a flexible sealant, not filled with grout. Grout cracking at a location that should have been a movement joint is a workmanship defect, not normal wear.

Incorrect fall in wet areas

Tiled shower floors and other wet areas must drain correctly. Incorrect fall — where the tiled floor does not slope towards the waste at the gradient required — results in water pooling and potential waterproofing failure.

Australian Standard AS 3740 (Waterproofing of domestic wet areas) specifies minimum gradients for shower floors. The standard minimum fall for most shower floors is 1:60 (approximately 17 mm per metre) to the waste point.

Check for incorrect fall by:

• Pouring a small amount of water on the floor and observing whether it flows naturally to the waste
• Using a spirit level to check whether the floor is truly flat or sloping away from the drain

If water pools away from the drain, this is a fall defect and the floor needs to be relaid to the correct gradient.

How to document tiling defects

Thorough documentation is critical to a successful claim:

1. Tap test and mark — go through the entire tiled area methodically, tapping every tile. Mark hollow ones
2. Photograph with scale — photograph every defect with a ruler, tape measure, or coin beside it
3. Describe the location specifically — “master bedroom ensuite, east wall, second row from bottom, tile 4 from left”
4. Photograph the full area — not just individual tiles; show context so the extent of the defect is clear
5. Note the date of discovery — timestamped photos via Checka are ideal for this

If you have tiling defects, raise them in writing with your builder immediately. During the defects liability period (DLP), the builder must rectify these without charge. After the DLP, you are relying on the statutory warranty — generally two years for non-major defects in Australia (longer for major structural or waterproofing failures).

Tiling defects versus acceptable variation

Not every imperfection in a tile installation is a rectifiable defect. Factors that affect assessment:

• Natural tile variation — handmade tiles, natural stone, and artisan finishes deliberately vary. What you accepted in the specification sample may include visual variation
• Tile specification vs installation standard — a tile specified for outdoor use installed correctly in an indoor bathroom is not a defect
• Age and wear — grout colour variation after years of use is not the builder’s responsibility

Before serving a formal defect notice, it is worth having an independent building inspector confirm whether the observed condition meets the threshold for a defect under AS 3958.1 or the applicable standard. Their report is significantly more persuasive to a builder and to a tribunal than homeowner opinion alone.

Key Takeaways

• Hollow tiles (debonded) are the most common tiling defect — check by tapping every tile methodically with a coin or knuckle during your practical completion inspection
• AS 3958.1 requires minimum 80% adhesive coverage (95% in wet areas); tiles that fail the tap test indicate coverage below this standard
• Acceptable lippage is typically 1 mm maximum for standard grout joints; use a straight-edge to check joints between tiles
• Cracked tiles in a new build are always a defect unless impact-damaged after handover; photograph and date every crack
• Shower floors must drain to the waste at a minimum gradient of 1:60 (AS 3740); water pooling away from the drain is a fall defect
• During the defects liability period the builder must rectify tiling defects at no charge; after the DLP, the statutory warranty (typically two years for non-major defects) still applies