Why Is My Tile Grout Patchy & Can I Avoid It?

Whether you’re installing a simple ceramic wall tile or a large format porcelain tile, they both require a grout join.  Tiles ‘breath’ and expand so are installed with a gap that is later filled in with grout.

As most grouts are made with cement, they are porous and susceptible to staining and discolouring.

Spills, dirt and even the oils from the soles of your feet can leave your tiled floor and grout contaminated and unsightly.  Sealing the grout can help as it may prevent stains that require chemicals to remove them.

An alternative to cement-based grout is epoxy grout.  Mainly used commercially it offers high chemical resistance and impedes grease and dirt absorption, however, is costly.

The next innovation in grout is fully acrylic, flexible, and non-porous:  Davco Ezy Grout.

  •  Easier to keep clean as is very resistant to staining, bacteria and mould.
  • Being premixed ensures colour and strength is homogenous throughout the application.
  • The tub is re-usable, once closed properly it can be used again within 12 months.
  • The application is slightly different to that of standard powdered grouts. For tips on how to use Davco Ezy Grout, view their video.

The use of Davco Ezy Grout will minimize the following issues that can arise when using cement-based grout:

Efflorescence (the grout has white patches)

A white  discolouration on grout in some tiled areas may be caused by mineral deposits in the mortar system being dissolved and rising to the surface as the grout cures.  This is called efflorescence.

As mineral salts are present in all elements used within a tiled structure (concrete, brickwork, render, adhesive, grout, screed etc.), efflorescence cannot be guaranteed against nor indicates the materials used are faulty.

Higher-than-normal concentration of salts in the air (mainly coastal regions) may also contribute to the appearance of efflorescence.

Smaller deposits may be cleaned with normal cleaning methods while difficult stains may require specific products. Try Davco Tile n Grout Cleaner or Aqua–Seal Oxy Treat HD.

For stubborn efflorescence try Davco Rejuvenation Grout.

Yellow Staining (the new white grout has yellow patches)

In limited tiling installations yellow patchiness of the white grout may occur possibly due to:

  • Residual moisture from the shower wall being absorbed through the grout whilst drying, can appear as a yellow/brownish stain in much the same way as efflorescence occurs.
  • Not following best practise to ‘wet down’ tile joins before grouting. A wetted tile prevents moisture from the grout being drawn in and then out again during the curing process.  This may cause yellowing as tannins present in clays used in tile production are transported to the surface of the grout.
  • Too much water in a grout mix may cause staining and a grout that dries too soft may (eventually) crumble.
  • Using the shower before the grout has had time to cure and/ or incorrect cleaning products may contribute to yellowing grout.


If yellow staining cannot be removed with the use of specific tile cleaners, regrouting with Rejuvenation Grout could rectify the issue.


Brown/Black Staining (in the shower area)

The culprit here is very likely to be mould.

Ventilation is a key factor for keeping wet areas free from this unsightly and pesky fungal growth.  If moisture accumulates and is not effectively aired out, mould will occur.   Using the exhaust fan when showering and keeping the bathroom windows open (even slightly) will allow air flow to dry showers.

Various hair care, body care and soap products may encourage fungi if not cleaned regularly.

In addition to routine cleaning and drying out of wet areas, a regrout with Rejuvenation Grout could eliminate or minimize issues with mould.

For more tips on how to keep your grout from getting dirty, see How To Clean Grout, and, How Do I Care For My Tiles?

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