Pressure Washing Tips for Cleaning Concrete Surfaces
Most concrete surfaces accumulate dirt so slowly that it is difficult to notice a change in their appearance. After cleaning the cement, however, many are shocked at just how dirty the cement was prior to the cleaning. Many people, as a result, will schedule periodic cleanings to keep their concrete’s clean appearance.
The main component of any good cement cleaning is a high-quality pressure washer. The right power washing equipment can save you a considerable amount of time, money and frustration.
The following tips will greatly facilitate the task of concrete cleaning:
1. It is important to use a power washer with that least 3,000 psi and with a flow rate of at least four gallons per minute. Many heavily soiled concrete surfaces may require higher flow rates of 5 or 6 gallons per minute, but generally speaking, 4 gallons per minute is usually sufficient.
2. When spraying the concrete surfaces, choose a rotary nozzle over a standard, fan nozzle, as the rotary nozzle allows the exiting water to spin in a circular pattern, which thereby allows it to flow at a higher speed.
3. Many concrete cleaners also find that wheel-mounted pressure washers allow them to clean more area in less time, thereby greatly increasing productivity.
4. Deciding upon a hot or cold pressure washer is often a difficult decision, as a cold-water pressure washer, although less effective, is about $1,000 less than its hot water counterpart and is often half the weight.
A hot-water pressure washer, on the other hand, cleans much faster and is generally the ideal choice for larger, commercial applications. Many concrete contractors realize that, although much more expensive than cold-water washers, the efficiency and cleaning capabilities of hot-water power washers usually offset the added expense.
In addition, a hot-water power washer is the best bet for cleaning oil and grease, especially in cold weather conditions.
5. Before using a power washer with chemical cleaners, check with the local municipality codes for restrictions on water run-off. Many municipalities restrict the run-off from entering the storm sewers based on the chemicals used and the contaminants being removed.
6. Power washers require routine maintenance because the high water pressure wears out the washer’s components, including the seals, the o-rings and the springs. There are a few things you can do, however, to extend the time between repairs: never run the power washer without water and never run the washer in the bypass mode for more than a few minutes.
7. Using chemical cleaners with a power washer is the ideal solution for stubborn concrete stains. Ideally, you should spray the stained area with the cleaner and allow it to sit for at least 15 minutes before power washing.
Oil is the most common type of stain, and is usually best removed using an alkaline degreaser. Alkaline degreasers are also the cleaner of choice for removing soot from concrete.
Heavy rust stains are best removed with a cleaner containing oxalic acid like CLR.