Joints with Rough Texture

Visualisation

The grout joint is rough to the touch, sometimes grains of the sand are found firmly anchored to the mortar at the surface. Reliefs and discontinuities appear in the texture, with an irregular distribution in the joint pattern.

Defect assignment

As a result of sand size, some grouts that have been well prepared and applied already display a more or less granular texture, which usually contrasts even more if the ceramic tile is glazed, smooth, and glossy. Since aggregate size is selected as a function of joint width, a certain surface texturing cannot, to some extent, be avoided. However, if the mixture is defective or too much water is used, and, in particular, if material is pulled away with a soft, water-soaked sponge in the first cleaning, that texturing will be increased until a rough surface develops that is unpleasant to the touch.

The same defect may develop as a result of chemical attack, and the foregoing remarks are equally applicable in this case, in both cement-based and reaction resin grouts. Surface contamination, when the joint material is still fresh, may also give rise to rough textures which, in addition, are usually accompanied by a change in colour. The same defect may also be caused by premature cleaning.

Prevention

This defect will not be present if:

• Appropriate grouts are selected for the joint width proposed by the manufacturer
• The mixture proportion proposed by the manufacturer is observed
• It is checked by touching that the material has hardened sufficiently (does not stain the fingers) before commencement of the cleaning operation after grouting
• The wall or floor tiling is protected against contamination by activities of other trades
• Cleaning is done diagonally with regard to the joint pattern, with a well-wrung-out sponge of medium stiffness