Have you ever looked at your driveway, walkway to your business, or any other concrete surface and been dissatisfied with the condition it is currently in? The exterior of your home or business is the first impression guests or customers will have of your residence. Why not make that a great first impression with a beautiful and clean environment for them to visit?
Here I am going to walk you through step by step how to get your concrete clean and restored back to its proper state. Over time either it is your driveway, sidewalk, patio, etc. grime and dirt will eventually build-up, and through these few steps, you can have it looking beautiful in no time.
Equipment needed: Pressure Washer w/ a 4 gal per minute pump, Pressure Washer Wand, Two 2 gal. Pump Sprayers, Surface Cleaner, 24? firm bristle brush broom, 6% Sodium Hypochlorite (SH), Water, 100ft hose, Spray nozzle, Water Source.
Now the first step may seem like an obvious one, but it is an important one, sweep off any standing debris possible. The last thing you need is to be fighting loose material as you begin the cleaning process. With a firm bristled 24? bush broom, clear away any standing dirt, or debris that is easily removable from the surface. Also, move any furniture that may be on the way to an area where it will not; 1. Get in the way and 2. Be affected by the SH solution.
Now that the area is clear of loose debris, take your pump sprayer, and for most concrete surface you will need only a 2% sodium hypochlorite mix. To get this we will need to use the dilution, begin by taking 25.6 oz of SH into your pump sprayer. (You will always want to put the SH in first, and then add water onto it, this will prevent you from potentially splashing yourself with the SH and avoiding any injuries.) Next, fill your pump sprayer the remainder of the way to 2 gal. (ie: 102.4 fl oz of water.)
Next, take your hose with the spray nozzle attached and LIGHTLY wet the entire surface of the area you are going to clean, this will help open up the concrete so you can remove any deep dirt or grime that has worked its way into the concrete. It will also allow the SH to sit on top of the surface longer, without drying, giving it a chance to further clean the area and erode away any organic material. After the entire area has been lightly soaked, we are going to ?pretreat? the entire area we are going to clean.
Pretreating is a crucial step because this will use our SH mix and allow it to sit on top of the surface we are wanting to clean, and it will begin to eat away at any organic build up on the concrete. Start from the top right corner of the area and work your way backward towards the end of the area making sure to cover the entire pad.
Now that the entire pad has been covered with our solution, you will need to allow it a ?sit time? of about 15 – 20 minutes. Use this time to get your pressure washer, surface cleaner, and hose all hooked up to the closest water source, and ready to go as soon as the set time is up.
The reason we recommend a 4 gal per minute pump opposed to a 2 gal per minute pump is the larger the GPM the more surface area a pressure washer can clean. Your standard pressure washers typically run as follows:
Consumer: Psi = 500 – 4,000, GPM = 1.0 -4.0, CU (Cleaning Units) 1,560 – 16,000, Water Temp = Cold
Semi- Pro: Psi = 1,000 – 4,20, GPM = 1.0 – 4.0, CU (Cleaning Units) 2,400 – 16,800, Water Temp = Cold
Professional: Psi = 1,000 – 7,000, GPM = 1.0 – 10.0, CU (Cleaning Units) = 2,500 – 30,000, Water Temp = Cold/Warm/Hot
Now for the fun part! Start your pressure washer by turning on the water source connected to it, pulling back on the choke, putting your throttle at a medium setting, and be sure to squeeze the trigger to release any pressure while you pull the cord to start it. As soon as it’s up and going we are ready to start. Choose which side you are going to want to start on, we advise starting in the same corner you first applied to since it has had the longest time to sit. Separate it out into ?sections? that you are going to clean. (Ie: the top right half first, then lower right half, then upper left half, then lower left half.) With the surface cleaner go around the entire perimeter of the 1st section, after the perimeter is done, go in a vertical direction across the entire pad, being sure to have a slight overlap each time (similar to mowing a lawn) to ensure even cleaning. This will prevent what is known as ?Tiger Stripes? from appearing after you are done, which is just uneven coverage of the area cleaned.
Be sure to move at a medium pace, not too fast, not too slow. You want the surface cleaner to be able to do its job efficiently, without damaging/etching the concrete. If you move too fast, you will get tiger striping and will have to make multiple passes to get a thorough clean. If you move too slow, you will potentially begin to etch the concrete and cause irreparable damage to the surface.
There are many benefits to using a surface cleaner as opposed to only a traditional wand, however, you will still have to use a wand for areas that the surface cleaner cannot reach. The surface cleaner can cover a much wider area of coverage than a wand can alone, it allows you to clean almost twice the area in the same amount of time. Wands also run the risk of leaving lines in the concrete or potentially etching the concrete if you are not careful. To avoid this, you should hold your wand about a foot away from the surface you are wanting to clean and move in one continuous motion from left to right, or right to left. The surface cleaner, on the bottom of it, has two oscillating sprayers on the bottom that spin and will clean a much larger expanse of concrete.
After you have gone in a vertical direction across the 1st section, now go in a horizontal direction starting from top to bottom in the same section. This will get you the deepest and most thorough clean possible and will eliminate any possibility of ?tiger stripes?. Now repeat this process on each section, always starting from the top of the area and making your way towards the bottom. This ensures that you are not pushing the dirt you currently cleaning from the next sections moving onto your now clean sections. (If you have a reclaim system this will prevent this all together and will collect any of the dirty water as it is pulled up from the concrete)
Always clean from top to bottom, starting from the top of the driveway or concrete surface and making your way towards the bottom. After each section has been cleaned, detach your surface cleaner and using the ball valve on your pressure washer hose, (or your wand would work just as well) wash away the standing dirt you just cleaned towards the bottom of the surface. You don?t want to allow it to dry back onto the surface or you will have to clean it again, and are only extending the time the process will take.
After you have made a pass in both directions on every section of the surface, now using your pressure washer wand, go back and check for any areas that the surface cleaner may not have been able to get. A lot of the time this can be sections that are right up next to a house or garage etc. Using the wand, maintain a good distance from the surface of the concrete (about 1ft) and in one solid movement spray any areas you could not get off with the surface cleaner. The reasoning for the one solid movement is you could potentially etch the concrete if you are using a ?back and forth? motion. Now use the wand to blow away any standing dirt into the nearby yard.
At this point, your surface should be looking great and back to its natural look. If there are any areas that you have noticed haven?t been removed ie: rust, oil stains, etc. This may take an application of a rust removal chemical, or a degreaser for the oil. If this is the case, in your 2nd pump sprayer mix up another 1:10 solution and apply to the area that needs to be treated and allow for a 15 min ?set time?.
BE SURE NEVER TO MIX ANY OTHER CHEMICAL INTO THE 1st PUMP SPRAYER THAT HAS YOUR SH SOLUTION! (This can cause a dangerous mixture of chemicals or their fumes which can be harmful or even deadly. Also, take extra precaution when handling any of these chemicals and be sure to thoroughly rinse any and all containers after their use.)
After your set time is up, run over the entire affected section again with the surface cleaner from both directions to ensure even cleaning. (If the stain persists you may need to go to a stronger solution)
Now that any separate stains have been treated and the entire pad has been cleaned, now it is time to ?post-treat.? The purpose of post treating is similar to when we pretreated, but now it is to further clean and kill any organic material that may still be present after all the cleaning has been done. (This is usually only required for very thick patches of moss, or tough stains that won?t seem to come out? However, we recommend post treating every single job, every single time. This will ensure the best quality of clean for your customer or yourself.
Turn off all of your equipment and now with your hose and spray nozzle make one final pass blowing off any standing dirt or debris. We recommend them coming through with a broom and sweeping up the loose debris and dirt that has been blown to the bottom of the road at the end of the driveway. Now that you cleaned your driveway, you don?t want to just leave all that accumulated dirt sitting at the entrance only to be tracked right back in. Sweep the debris/dirt and dispose of it in a yard waste bin. And, Tah dah! You just cleaned your first concrete surface. Admire your work, and as it dries watch the color revert back to its natural state.