What Is Pressure Washing?
You’ve probably heard power washing and pressure washing used interchangeably, and, while they are very similar, there is one key difference. A power washer has a heating element to heat the water while a pressure washer does not. So, what is pressure washing?
What both do have in common is that they use high-pressure water to wash anything they are pointed at (well, almost anything). A pressure washer hooks up to your water supply and then pressurizes it to shoot out a jet of water, and there is often a place to add detergent to create pressurized soapy water.
When you pressure wash, the jet of water removes the top layer from whatever you are washing. Most commonly, this will be dirt or grime. It does a great job of removing superficial dirt and can even remove moss and lichen, but may not be as good on ingrained stains in something like concrete. For that, you are going to want to power wash.
Why Pressure Wash Before Painting?
The most obvious reason is to ensure that you have a clean surface to paint. If you paint on a dirty surface, not only is there going to be a layer of dirt between the paint and the surface, but that layer of dirt might also show through, especially over time.
When you have a dirty surface, the paint does not have a chance to soak into the material below, and this means that the material is not fully protected. It can also result in chipping and cracks. If the dirt starts to loosen, the paint is going to come away with it too.
You will also be unlikely to have a smooth finish. Even a little bit of dirt on a wall is going to create an uneven texture when the paint is applied. When your walls, or anything else, is painted flawlessly with fresh paint, it becomes really easy to spot slight imperfections.
With all of this in mind, it is not hard to see why a paint job after pressure washing can last 7+ years while painting on material that is not cleaned may only last 2-3 years.
How Long Should I Wait Before Painting?
Your wait will depend on the type of material that you are washing. If you are pressure washing the exterior of your home, aluminum and vinyl are going to dry a lot faster than wood, which will soak up more of the moisture.
We recommend letting the material dry for 24 hours before painting, but you should also perform a visual inspection and touch the material to check for dryness.
What Happens If I Don’t Wait?
The main problem with not waiting for the material to dry is that the paint is not going to adhere to the material as well, especially in the case of wood. With wood, you want the paint to soak into the material, and it will be unable to do this. So, while the material may look painted, it will need to be repainted far sooner, perhaps even after a year.
For the materials that do not require absorption, you are going to be watering down the paint, leaving you with a color you did not choose, and uneven coverage, depending on the amount of moisture. In extreme cases, you might have lots of drip marks running down the walls.
We recommend planning your paint job so that you leave yourself lots of time to pressure wash before painting. Giving the material sufficient time to dry is going to save you more time in the long run.
What to do while you wait
While you are waiting for the material to dry, there are numerous things that you can do. We like to use this time to ensure that we are prepared for the job. In most cases, you are going to be painting the next day, or soon after, so check that you have all of your materials and accessories.
You can also start moving any obstacles that are going to be in your way when you paint. Are there overhanging tree branches that can be cut or furniture that can be moved away from walls? How about any fixtures that can be removed? Or nails to be hammered in? Take a look at the surface that you are painting and make sure that you are ready to paint as soon as it is dry.
Of course, if you have planned ahead and all the prep work is done, then why not relax in your yard with a cold drink. You deserve it.