Power Washing Pros · 715-446-4271 · powerwashingproswittenberg.com
The short version
Pavers get the same kind of surface cleaning as concrete, but with more care: the sand in the joints holds the whole patio together, and cleaning loosens or washes some of it out. Weeds, moss and the green film come out with the dirt. Afterward, the joints usually need fresh sand, and the patio is ready for sealer if you want it sealed.
Signs it's time
- Weeds and moss growing up between the pavers.
- A green or black film, especially in shade.
- Pavers that have faded and all look the same dull grey.
- Joints that are empty, or pavers that have started to shift or rock.
- Ant hills in the joints.
What cleaning does for pavers
The surface of a paver collects dirt, algae and mildew the same way concrete does, and the joints between them collect soil, seeds and organic debris — which is what weeds and moss grow in. Cleaning takes both out, and brings back much of the color the pavers had when they were laid.
The joint sand question
The sand between pavers isn't filler. It locks the pavers against each other so they don't shift, and it keeps weeds and ants out of the joints. Any real cleaning will loosen some of it, and dirty, weedy joints often need to be cleaned out anyway.
So a cleaned patio usually needs re-sanding afterward: fresh sand swept into the joints. Polymeric sand, which hardens when it is wetted, holds up better against weeds and washing out than plain sand. Ask on the call whether it can be done on the same job.
Sealing
A sealer on clean pavers deepens the color, helps shed stains and slows down the green coming back. It goes on after the pavers are cleaned, the joints are re-sanded and everything is dry. It's a separate job from the cleaning, and worth asking about if the patio gets a lot of use.
White haze on pavers
A white, chalky bloom on pavers — especially new ones — is usually efflorescence: salts coming up from inside the paver as moisture evaporates. It is not dirt, and pressure washing can bring it back. See the efflorescence guide.
Stamped and colored concrete
Stamped concrete patios and walks are usually colored and sealed at the surface. They get cleaned more gently than plain concrete, because the color and sealer can be worn off. A stamped patio with a worn, patchy sealer usually looks best after cleaning and resealing.
What a wash will and won't do
Washing will
- Clean the surface of the pavers and bring back much of their color
- Clear weeds, moss and debris out of the joints
- Take the slippery film off shaded walks and steps
Washing won't
- Put the joint sand back — re-sanding is its own step
- Level pavers that have sunk or shifted
- Remove efflorescence for good — the moisture causing it has to be dealt with