Your Flagstone Is Probably in Color

Red brick paver patio in Havertown, PA after pressure washing, the brick bright and the joints clear

Here is something that happens more than you would think.

Someone buys a house with a gray stone patio.

They like it fine. They buy gray chairs so it all matches. They get a gray grill. It is a very calm, very gray patio.

Then one day, the patio gets washed.

It is red. And blue. And green.

Now nothing on it matches, and the chairs are taking it hard.

Most gray flagstone is not gray. It is just wearing a coat of grime.

Why stone turns gray

Flagstone has tiny holes all over it. Dirt, pollen and algae sink in. Shade and trees make it worse, because the stone stays damp.

After a few years, every stone turns the same dull color. It looks old. It is really just dirty.

Why you should not blast it

Stone is softer than it looks. So is the mortar between the stones. Too much pressure can chip the stone and dig out the joints.

We use lower pressure and the right cleaner. The stone stays put, and the joints stay full.

Signs your patio needs a wash

All the stones look like the same color.
The lines between the stones are dark or green.
It feels slick after it rains.
Weeds and moss grow in the cracks.

How we clean stone

We look at the stone and the joints first.
We put down a cleaner to loosen the grime and kill the green.
We rinse with low pressure, a little at a time.
We clean the joints at an angle, so the sand and mortar stay in.

What if it is not flagstone?

Lots of patios are brick, pavers or plain concrete. They turn gray too.

Brick turns back to red. Concrete turns back to tan or light gray. Pavers show their pattern again.

Each one gets its own pressure. Brick and pavers get less. Concrete can take a bit more.

Pool decks are patios too

A pool deck is a patio that gets splashed all summer. So it grows green fast.

Green on a pool deck is slippery. That is not a look anyone wants next to a pool.

We clean pool decks the same careful way, and we keep the dirty rinse water out of the pool.

What will not come back

Cleaning shows the real stone. It does not make old stone new.

Chips and cracks show more once the dirt is gone. Some stains, like rust from a metal chair, need their own treatment.

We tell you about those before we start, not after.

The best time to do it

Spring is great, once the pollen and the seeds have fallen. Fall is great too, after the leaves are down.

Wet leaves left on stone all winter can leave brown shadows. So a fall clean is worth it.

A few quick answers

Will you seal my patio? No. We clean it. If it looks like it needs a sealer, we will tell you what we see.

Do I need to move the furniture? It helps if light chairs and pots are off the patio.

How long does it take? Most patios are done in a few hours.

Can you clean around my plants? Yes. We wet them first and rinse them again at the end.

What about my dog? Keep pets inside while we work.

Can you clean a brick patio? Yes, at a lower pressure, so the brick and the joints stay put.

Your patio is a little like a sponge

Flagstone looks solid. Up close, it is full of tiny holes, a bit like a very hard sponge.

Water sinks in. Dirt comes with it. Green things grow in it. Over time, the top of the stone fills up with all of it.

Cleaning pulls it back out of the holes. That is where the color has been hiding.

Colors you might find

Rusty reds and oranges
Blues and blue-grays
Soft greens
Warm tans and browns
Dark slate

Every patio is different. That is part of the fun.

The lines between the stones

On a flagstone patio, the joints are filled with mortar or sand. They hold the stones in place.

Blast them, and they wash away. Then the stones can wobble, and weeds move in.

So the joints get a gentle clean, at an angle. We want them clean, not gone.

Shade, trees and your patio

A patio under a tree gets leaves, seeds, pollen and bird mess all year long. It also stays damp.

That does not mean the tree has to go. The tree gets to stay. It just means the patio will want a clean a little more often.

Stone and your grill

Grease from a grill can drip and leave dark spots on stone. Fresh spots often lighten with the right cleaner. Old ones may stay.

A mat under the grill helps keep the stone clean next time.

Why it gets slippery

That green film is not just ugly. It is slick.

When it rains, the film holds water right on top of the stone. Step on it in flip-flops and you will find out fast. Please take our word for it instead.

Once the film is gone, the stone has its grip back.

Weeds in the cracks

Seeds love the sand between stones. They land, they sprout, and soon the patio has a little garden of its own.

We clean the moss and growth out of the top of the joints. Weeds with deep roots come out with their roots.

If a joint has lost its sand, the weeds will come back faster. We will point those spots out.

Stone steps and walls

Most stone patios come with friends: steps, low walls and a path to the yard. They get the same gray coat.

We clean them along with the patio, at the same careful pressure. Then everything matches.

How often to clean a patio

Once a year works for most shady patios. A patio in full sun can go longer.

If yours sits under a big tree, it may want a clean every spring and a quick one in the fall.

What to do before we come

Move light chairs, tables and pots off the patio.
Put the grill somewhere else for the day.
Bring pets inside.
Make sure an outdoor spigot works.
Tell us about any stains that bug you.

What it is like after

The stone stays damp for a little while. Then it dries, and the color shows up.

Most people walk out the next morning and stare at it for a minute. That is normal. The patio has been hiding for years.

Then they start to think about new chairs. That part is up to you.

A real one from Havertown

We cleaned this flagstone patio in Havertown, PA. Drag the handle to compare. Same stone, same spot. Nothing was painted, stained or sealed. The color was there the whole time.