Decks must be completely clean before they are sealed, so that the sealant will adhere to the wood properly. This is most easily accomplished by powerwashing the surfaces. A sealant remover is applied when sealant remains on the surfaces from previous applications, followed with a brightening/neutralizing process, to offset the effects of the chemicals on the wood. A description of these services and the process our crews follow is explained below.
- REMOVING DECK SEALANT & DECK STAIN FROM PREVIOUS APPLICATIONS
- BRIGHTENING/NEUTRALIZING AFTER CHEMICAL APPLICATIONS
- WHEN THE CREW ARRIVES …
- WHEN THE DECK CLEANING IS FINISHED ….
A high-pressure stream of water is passed through a wand that is moved slowly and carefully, back and forth along the grain, over exposed wooden surfaces to be cleaned. The powerwasher pump converts garden hose pressure of 40 psi (pounds per square inch) to as high as 3000 psi. Pressure is adjusted during cleaning as appropriate to the wood’s type, age and condition.
REMOVING DECK SEALANT & DECK STAIN FROM PREVIOUS APPLICATIONS
Deck sealant and stain remaining from previous applications must be removed prior to resealing. Powerwashing alone can accomplish this in some instances, with clear sealants and toners, for example, but often not with other sealant types. In those cases, the surface can be sanded with an orbital sander, or a SEALANT REMOVER can be applied. The sealant-covered surfaces are “painted” with the liquid sealant remover, allowed to work for about 15 minutes, then hand-scrubbed with deck brushes and rinsed with a garden hose or powerwasher to remove all traces of sealant. This process is also recommended for sensitive wood surfaces, like cedar, that could be very easily damaged by high-pressure water.
BRIGHTENING/NEUTRALIZING AFTER CHEMICAL APPLICATIONS
The sealant removal process must always be followed by the application of a BRIGHTENER (oxygen bleach or an oxalic acid compound), to neutralize the chemical effects of the sealant remover on the wood. Several rinses, and often a light powerwashing, are applied to complete the neutralization process. These chemical processes can be very messy and VERY HARMFUL TO PLANTS, so special care is taken to prevent the rinse overflow from falling onto surrounding plant life or pouring into the soil.
WHEN THE CREW ARRIVES …
Temporary access to a working water source, and to all areas in which the work is to be performed, must be provided prior to the work’s commencement. Plants and/or areas that ought to be protected from the water stream (or chemicals, when using brighteners or sealant remover) are relocated, if possible, or covered in plastic. Shrubs or small trees growing near the surfaces to be treated are covered with plastic fencing and pulled back and away from the surface area when possible.
High-pressure hoses are brought to the highest level of the areas to be cleaned, then lowered to ground level and connected securely to the powerwasher. Garden hoses from the water source are then connected to the powerwasher as well, the water is turned on and the VERY noisy powerwashing machine engine is started. Several powerwashers are often used concurrently to minimize completion time.
WHEN THE DECK CLEANING IS FINISHED ….
There is ALWAYS a brightened color change, because a thick layer of the dark, dingy color of bacterial damage, sun damage, greying and seasonal stresses are removed with the high-pressure water. The exact degree of lightening to be expected is dependent upon the wood type, the age and the condition of the wood. Residents may walk on the surfaces immediately after powerwashing and use them in the days following, while they are drying and waiting to be sealed.