There is absolutely nothing wrong with wanting your patio or driveway given a quick pressure wash.
Sometimes that is exactly what is needed. A bit of winter grime, some green algae, general dirt, a surface that just needs brightening up. Give it a decent clean and everyone is happy.
But that generally is not why people come to Chiltern Surface Co.
More often than not, we are called when somebody has already had a go themselves. They have bought a pressure washer, spent the best part of a Saturday getting soaked, sprayed half the garden up the kitchen windows and finished the day feeling fairly pleased with the result.
Then the patio dries. And the black spots are still there. Or the lichen is still there. Or the green comes back six months later. Or, after repeating the same process every spring for years, they start to notice that the patio somehow seems to be getting harder to clean rather than easier.
That is normally where things become more interesting, because the question stops being, `How much pressure do we need?' and becomes, `What is actually happening to this surface?' And that is a much better question.
Pressure washing is one part of the process
At Chiltern Surface Co, we do not really consider pressure washing to be the service. We consider it a tool. A very useful tool, certainly, and one we use every day, but still only one tool amongst a whole range of methods available to us.
Depending on the surface and the problem, we might use pressure washing, specialist chemical treatment, soft washing, heat-assisted cleaning, biological treatments, manual restoration or a combination of several different processes. The important thing is that the surface tells us what to use. Not the machine.
That sounds like a small distinction, but it changes the whole way you approach exterior cleaning. If you arrive at every property thinking, `How am I going to pressure wash this?', you have already decided on the answer before you have properly understood the problem.
We would rather start with the surface itself. What is it made from? Sandstone? Limestone? Porcelain? Concrete? Brickwork? Block paving? Render? Has it been sealed before? Is it porous? Is the jointing sound? Is the problem ordinary dirt, algae, lichen, black spot, rust, oil, efflorescence, a failed coating or something else entirely?
Those questions matter because two patios can look remarkably similar from the garden gate and require completely different treatment once you actually inspect them properly.
Not everything on your patio is dirt
One of the biggest misunderstandings in exterior cleaning is the idea that everything dark or green on a patio is simply dirt. Quite often, it is biology.
Green algae, moss, lichen and what people commonly call black spot are all biological growths. They behave very differently from ordinary surface dirt, particularly when they become established on porous materials such as sandstone, natural stone and brickwork.
That is why somebody can spend hours pressure washing a sandstone patio, remove an astonishing amount of grime and still find, once it dries, that the black marks are sitting there looking completely untroubled by the experience.
The natural reaction at that point is more pressure. Then a bit more. Then perhaps move the lance slightly closer. And this is where things can start getting expensive.
More pressure is not always more cleaning
Natural stone is not indestructible. Sandstone, for example, is porous, textured and naturally variable. If you keep concentrating high pressure on a stubborn area, eventually you can begin affecting the stone itself rather than just the contamination.
You can roughen the surface, disturb the joints and alter the finish. There is a point where you stop cleaning the patio and start removing tiny parts of the patio. That is not really the objective.
Our philosophy at Chiltern is straightforward: we use the lowest amount of pressure and the least amount of chemistry required to achieve the desired result.
That does not mean we are afraid of either. We use serious pressure-washing equipment and professional cleaning chemistry all the time. The difference is that we want a reason for using them.
If something genuinely needs more pressure, we increase it. If something needs treatment, we treat it. If the problem is biological, then at some point the biology has to be addressed.
Trying to solve every exterior-cleaning problem by simply increasing the pressure is a bit like trying to photograph every scene with the same lens. You might get away with it occasionally, but sooner or later you are going to find yourself with completely the wrong tool for what is in front of you.
The equipment should follow the problem. The problem should never be forced to fit the equipment.
Why does the black spot keep coming back?
One question we hear all the time is, `Why does the black spot keep coming back?' Usually there is more than one reason.
Firstly, the environment has not changed. If a patio is damp, shaded, surrounded by planting and slow to dry, it remains a very pleasant place for algae, lichen and other biological growth to establish itself.
Secondly, pressure washing may remove a lot of what is visible without fully dealing with the biological contamination associated with it.
And thirdly, if a porous stone surface has been repeatedly cleaned too aggressively, the texture of that surface can become rougher. A rougher surface can hold moisture, dirt and organic material more readily than a smoother, sound surface.
So sometimes the answer is not another annual battle with a pressure washer. Sometimes the better answer is to stop treating the visible symptom and start dealing with the reason it keeps happening.
A clean patio is not necessarily a treated patio
This is where treatment becomes important. A clean surface and a treated surface are not necessarily the same thing.
Pressure washing can produce an incredible transformation. That is why before-and-after photographs in our industry are so satisfying. You can take a patio that looks almost black in the morning and have the original colour returning by lunchtime.
But the job does not necessarily finish when the surface looks clean.
Where biological growth has become established, we can follow the restoration process with Chiltern EverGuardTM, our specialist biological treatment designed to help deal with remaining growth and protect the surface against regrowth for approximately 12 to 24 months, depending on the material and the environment.
The cleaning stage deals with what you can see. The treatment stage is about what happens afterwards.
That is the part that interests us. We are not particularly interested in making something look fantastic at four o'clock on a Tuesday afternoon if the customer is back in exactly the same position a few months later.
We would rather understand why the problem occurred, restore the surface properly and then give it the best possible chance of staying that way.
Sometimes our customers have already done most of the cleaning themselves
A lot of the people who call us have already done quite a bit of work themselves.
They may know exactly which corner of the patio turns green first. They know which slab always seems to stay damp. They have researched patio cleaners, bought a decent domestic pressure washer and lost several weekends trying different things.
They are not necessarily calling us because they cannot be bothered. Quite often, they are calling because they have realised that the problem has moved beyond simple cleaning.
They have done the pressure washing. It still does not look right.
That is where knowledge becomes more useful than horsepower. And, to us, that is one of the most important parts of the job.
We want customers to understand their surfaces
We want customers to understand what is happening to their property.
If we believe the black marks across a sandstone patio are established lichen, we will explain that. If we think a surface has been damaged by previous aggressive cleaning, we will point it out. If one part of the patio is significantly greener because it gets no sunlight and stays damp for longer, we will explain why that matters.
If the jointing is failing, if a previous sealer has broken down, if the problem is staining rather than biological growth, we want the client to understand that as well.
We do not want to simply turn up, blast everything clean and disappear. A property owner should know what is happening to the surfaces around their home. Once they understand that, they can make much better decisions about how those surfaces are cleaned, treated and maintained.
The surface tells us what to do
This is really the principle behind everything we do.
Sandstone should not be treated like porcelain. A roof should not be treated like a driveway. Render should not be treated like block paving. A delicate natural stone terrace should not be approached in the same way as a robust concrete yard.
The surface dictates the method. Sometimes that means pressure washing. Sometimes soft washing. Sometimes specialist chemistry. Sometimes manual work. Sometimes heat. Quite often, it means a carefully considered combination of several processes.
There is no prize for using the biggest machine. The only thing that matters is achieving the desired result without unnecessarily damaging the material underneath.
Anyone can buy a pressure washer
Anyone can buy a pressure washer. You can buy a very good one. You can buy an enormous one. You can buy one powerful enough to make the neighbours slightly concerned about what exactly you are planning to do with it.
But the machine does not tell you what the stain is. It does not tell you how porous the stone is. It does not tell you whether the black mark is biological growth or something else. It does not tell you when chemistry is the better option. It does not tell you when to reduce the pressure. And, crucially, it does not tell you when to stop.
That comes from training, experience, testing, knowledge and care. And that, in our view, is where the real value lies.
Why people come to Chiltern Surface Co
Some people simply want a quick wash, and that is absolutely fine.
But the people who come to Chiltern Surface Co are often looking for something more. They want to know why their patio keeps getting worse. Why the black spot will not disappear. Why their sandstone no longer looks the way it did when it was laid. Why the algae keeps returning. Why one area responds beautifully to cleaning while another stubbornly refuses to.
They want the problem understood properly. They want the correct treatment. They want the surface restored with care. And they want to know what can be done to help stop the same problem returning year after year. That is what separates a quick clean from proper exterior surface restoration. Pressure washing is part of what we do. Sometimes it is a very important part. But it is not the service. The service is understanding the surface, choosing the right process and knowing how to look after it properly. That is the Chiltern difference.