Concrete Paver Cleaning
Professional Cleaning of Concrete Pavers and Paver Tiles
Concrete Paver Cleaning Regular concrete paver cleaning, re-sanding, and sealing is needed to keep concrete pavers looking clean and new. Concrete pavers are very coarse, porous, and absorbent when unsealed or when the paver’s sealer has broken down. Dirt and organic material get embedded deep in the paver and in the sand in which the pavers are set. Concrete pavers get cleaned using a pressure washing system. Pressurized water is used to blast the deeply embedded soils and organic material from the pavers and leveling sand.
If the pavers have been sealed with a topical coating it will most likely need to be stripped from the pavers before cleaning.Pavers are usually sealed with a solvent based coating. To strip this type of coating from the pavers a solvent based coating stripper is applied to the entire surface. This breaks down the acrylic in the topical coating and causes it to soften and rise to the surface where is can be removed.
The pavers are pretreated with a 10-15% muriatic acid solution. This will loosen embedded stains and get them ready for pressure washing. Areas with heavy organic staining should be pretreated with a concentrated bleach solution. Pressure washing is used to draw the dirt and organic material from the pavers and remove it from the environment using an oscillating pressure wash tip. This spins the water creating more energy to drawdirt and organic material from the pavers. Dirt and detergent are worked with the flow of water to move it to a place where it can be collected and removed.
When the pavers in an area have been cleaned the surrounding walls, fixtures, and screens are lightly washed to remove any debris caused bythe pressure washing. Areas that did not restore completely with the pressure washing may need special attentions. Oily areas near grills may need a poultice to draw the oil from the paver, rust spots need to be treated with a rust remover and rinsed, and heavy organic stains (Plant food, Urine, mildew, etc) treated with a concentrated bleach solution. These areas will then need to be pressure washed again. Pressure washing the pavers will remove some or all of the sand between the pavers. Areas that get a lot of rain runoff may also have had the sand eroded from under the pavers. Left uncorrected this would cause the pavers to become unleveled over time.
Re-sanding the area and working the sand under the pavers will help to keep your paver floor level by working sand under your pavers to fill developing voids. Leveling sand is spread over the pavers and brushed across it to fill in the cracks. A soaker hose is used to soak the sand down under the pavers. The water caries the sand under the pavers to fill the voids. This stabilizes the floor and reverses the process of erosion.
A paver floor should be re-sanded twice a year. After sanding the pavers are allowed to dry thoroughly. Then the deck is swept clear of extra sand and gotten ready for the application of a sealer. The two choices of sealer on pavers are topical coatings and penetrating sealers. There are strengthsand weaknesses to both types of sealer.
Topical coatings are sealers that form a protective barrier across the surface of the material they are sealing. Outdoors, most coatings are a solvent base that is very durable but very difficult to work with. Solvent based topical sealers will give depth to the color of your pavers and a slight luster to the surface. Solvent sealers are very moisture sensitive and will turn white if the pavers are not completely dry when applied. Solvent coatings will last between one and three years before needing to be stripped and re-coated. Penetrating sealers work by soaking into the pores of the pavers and changes the chemistry of the paver so that water doesn’t soak in and oils don’t adhere to the surface. This protects the paver from inside the paver. Penetrating sealers used outdoor need to have a UV protector to keep sun exposure from quickly degrading your sealer. Never used an indoor sealer outdoors. It is a waste of money.
After service your paver deck will need periodic light pressure washing to keep material from building up on the surface and regular light bleaching to prevent organic material from growing. To bleach the pavers fill a pump up sprayer with pool chlorine and lightly mist the pavers. This should be done monthly ten months out of the year and every other week in July and August.