Why You Should Wash Your Car Top to Bottom


Washing your properly is really important. Improper wash technique can inflict all kinds of damage to your car’s paintwork, like as scratches and swirl marks.

One of the biggest questions that people washing their car’s at home ask, is if you should go from top to bottom, or bottom to top?

In this article, I’ll be discussing why washing your car from top to bottom is super important if you want to avoid scratches. So let’s get started.

The Quick Answer

You should wash your car from top to bottom. Most of the dirt on your car is on the lower sections so washing from top to bottom avoids dirt being transferred to cleaner areas of the paint. It’s important to avoid rubbing dirt into the paintwork because this causes scratches and swirls marks in the paint.

Improper Wash Technique Causes Scratches

First things first, we need to talk about how bad wash technique actually causes scratches in your car’s paintwork. To understand this properly, we need to know what your car’s paint looks like.

Here’s the structure of your car’s paint. The two most important layers to consider, are the base coat and clear coat.

The base coat is what gives your car it’s colour. Then layered over the top, is the clear coat. This is usually around 3x thicker than the base coat. The clear coat is super important because it’s what protects the base coat.

The clear coat protects the base coat from UV rays which cause fading over time, and from things like acid rain, bird mess, tree sap and road tar.

Unfortunately, the clear coat is actually pretty delicate. It’s prone to minor scratches which aren’t usually visible in normal light, but can be seen in direct sunlight.

These clear coat scratches are what makes your car look dull and lack lustre. Pretty much every car has them.

These clear coat scratches and swirl marks are caused by improper washing. You see, when you wash your car with something aggressive like a sponge, or dry it with a bathroom towel which has coarse fibres, the clear coat get’s scratched up. Like I said, it is super delicate.

Clear coat scratches are caused by pretty much any type of light friction. For example, when you wash your car and rub the dirt and grit over the surface, you’re actually causing tonnes of tiny scratches.

Washing Top to Bottom Reduces the Risk of Scratches

One of the best things you can do to avoid inflicting these kinds of scratches, is washing your car from top to bottom.

This minimises the amount of dirt you are rubbing into your car’s paint with your wash mitt.

Usually, most of the dirt on your car is concentrated to the lower panels. Usually, the majority of the dirt and grime on your car is caused by driving in the rain and through puddles. The dirty water splashes up onto your car and sticks to it.

Of course, there will be some dirt on the top of your car from things like bird mess, and dust settling, but generally, most of the dirt is on the lower panels.

When you wash top to bottom, you avoid taking the dirt from the lower panels and rubbing it into the paintwork higher up on the car.

Instead, when you wash top to bottom, you’re essentially washing the cleaner sections first. So you don’t transfer dirt to the clean areas.

This means that there’s less risk of you rubbing dirt into the paintwork, causing friction and inflicting clear coat scratches.

Best Order of Washing

If you want to wash your car safely and avoid inflicting scratches, then you should follow this order of washing the different sections of your car.

I always give my car a blast with a snow foam cannon after rinsing with a pressure washer. Check out this article I’ve written about snow foam cannons to learn more about how they reduce the risk of causing scratches when washing.

1. Wash the Wheels

The first thing you should do, is wash your wheels, this is because when you wash your alloys and tires, a lot of the dirt will splash up onto the paintwork. If you wash the wheels last, then you’ll end up getting mud and grit all over your freshly washed paint.

I’ll first give the wheels a good rinse with a power washer. I usually start with the tires. Check out this article I’ve written to show you how to make your tires look brand new again.

Next I wash the alloys with a soft bristle brush and wash mitt. Then I’ll give it a final rinse down before moving onto the paint.

2. wash the roof and windows

The next thing I’ll do, is wash the roof and windows. These are usually the least dirty areas of the car so it makes sense to wash them first. Also the shampoo suds will run downwards helping to lubricate the paint lower down, further reducing the risk of scratches.

3. Wash the Bonnet

Once the roof and windows are sorted, I wash the bonnet. This is because it’s usually the area of the car that get’s the most attention, so I want to make sure it doesn’t get scratches or swirls because they’ll be seen very easily.

Always make sure you keep checking your wash mitt for dirt. If at any point it looks dirty, then give it a rinse with a power wash or strong hose, or swap it out for a clean one.

4. Wash the Sides

Then I’ll move onto washing the sides. Again, I’ll go from top to bottom. The sides of your car can get incredibly dirty so you need to check your wash mitt frequently and rinse if necessary to avoid grinding dirt into the paintwork and causing scratches.

5. Wash the Back

The back of the car is usually the most dirty, particularly the lower end. This is because a lot of dirt will splash up from your rear wheels. Make sure you go from the top to bottom and use plenty of car shampoo and water to keep the paint lubricated and reduce the friction.

Check out this complete guide to washing your car without causing scratches.

More FAQs

Here are the answers to some of the most frequently asked questions about washing your car safely and effectively.

Should you rinse your car from top to bottom?

You should rinse your car from top to bottom so that the dirt (before you wash) and shampoo suds (after you wash) runs downwards off the paint and onto the ground. If you rinse from bottom to top, the dirt or shampoo you’ll have to use more water to thoroughly rinse your car.

should you snow foam your car from top to bottom?

It’s important to use a snow foam cannon from top to bottom to avoid using excess foam. Snow foam normally only stays on the car for a few minutes and it’ll run off a lot faster if you apply it from bottom to top.

Thanks for reading! I hope you’ve found this article helpful. Don’t forget to check out the rest of the blog to learn more about making your car look its best.

Heather

I first became interested in car detailing around 3 years ago and learnt all the main techniques on my very first car. I spend a lot of time detailing my current car, and trying to keep my family's cars looking presentable too!

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