What is washing-in?
Washing-in is filling joints, seams or voids with a thin, flowable mortar, pointing slurry or grout so that they fill more or less by themselves. The thin mix is worked over or into the work and washed into the joints with water or a brush, after which the surplus material is removed. The technique is used mainly for paving, tiling and sometimes for filling voids in masonry.
Application
Washing-in takes several forms:
- Paving — joints between pavers or slabs are filled by brushing or washing jointing sand or a jointing mortar in until the joints are full.
- Tiling — when grouting floor or wall tiles, the grout is drawn across the surface with a rubber float and washed into the joints.
- Masonry and voids — thin mortar (grout) can be poured into seams or cavities to fill them.
Points to watch
The right consistency matters: the mix must be thin enough to run into the joint, but not so watery that it slumps or washes out. Work in dry, not too warm weather, so the material does not stiffen too quickly. Remove surplus mortar or sand from the surface before it hardens, or a haze that is hard to remove will form. With outdoor paving, joints are often topped up later, because the jointing material settles or washes out over time.
Related terms
- Joint
- Mortar
- Grout
- Paving pattern
- Concrete paver
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