Exterior Brick / Concrete Cleaning Question

[asphaltgambler]

End of this week, I'm taking a few days off to catch-up on some home projects. One of which is pressure washing the brick front of my home along with my porch which is also brick and concrete.

My question is: do I need a concrete cleaner specifically (to be siphoned into) the pressure washer? I have some staining and black mold on the brick face and patio floor and see masonry cleaning products that say 'etching" - do I need that?

[GH85Carrera]

Personally, I would hit it with just water and pressure first to see if it removes the stains and mold. If not, then try some cleaner mixed in. Your yard and plants may not like the soap or cleaner much.

[masraum]

I'm not an expert, but I think a little bleach will do the trick for black mold. Maybe even spray it on first out of a hand spray bottle, let it sit a bit, then pressure wash with just water. I don't think you need a cleaner solution at all.

[stomachmonkey]

I use a standard $10.00 1 gallon pump sprayer with a bleach solution to deal with areas like that.

[javadog]

You don’t want a brick or concrete cleaner.

Bleach will kill the mold, then rinse it off.

Watch the pressure, you can damage the brick.

[asphaltgambler]

Got it - thanks!

[javadog]

I should probably also point out that full strength bleach isn’t needed. Mold is easy to kill, a little bleach goes a long way.

[dad911]

I try not to powerwash brick. Bleach and a garden hose sprayer.

[Superman]

Mildew is black. Bleach eliminates it instantly, right before your eyes. It also kills other stuff. I'd use bleach without worries, but I would be careful about pressure washing masonry.

[Superman]

A comical scene unfolded in a neighbor's driveway last night. Young fellow was using dad's pressure washer to wash a car. He seemed to know the dangers since he was holding the want at a substantial distance but I still thought it was a bad idea. The car was a decent one. Late model. Silver.

Then he put that car in the garage and went to work on his buddy's car, which has dark paint and is 15 years old or so. BIG wheels. At any rate, when he was done I noticed a number of rectangular patches on the car where the paint finish was stripped and flat instead of shiny. There was no yelling, but some excited discussion between the fellow, his buddy, and a girl.

Moments later, dad appeared on the scene and participated in the discussion. The silver car was pulled back out of the garage, for inspection I assume.

A pressure washer will do a number on masonry grout. I would not use a pressure washer on masonry. Not even concrete.

[rusnak]

You can use a pressure washer on paint. BUT you can't use high pressure. Most machines have the ability to turn the pressure way down. And they have interchangeable tips. You have to use the widest angle - the one that is used for dispensing soap is ideal. In fact, the better foam cannons are made to use with pressure washers.

I pay a guy to pressure wash the concrete "driveway" areas once per week, using concrete driveway cleaner on the greasy areas and a rotary brush. Sometimes I jump in and clean it with my pressure washer, and sometimes with a booster pump and a hose. Zep Concrete Cleaner is my preferred cleaner.

I would not use bleach on masonry, nor on grout, which is really soft and porous. Just plain water, maybe soap if needed, and maybe a pressure washer on the very lowest setting, or a booster pump with an adjustable fan spray. The vertical "fascia" areas are quite different from the horizontal traffic areas in terms of materials used, type of staining, and type of cleaners that you should use.

[Baz]

This stuff is the cat's pajamas. I tried it a couple years ago and now use it to clean anything that has gunky algae, mold, etc.

House
Walks and drives
Boat
Outdoor furniture
Shower/bath

I've tried all kinds of stuff but this stuff dominates!

You can buy it in a dispenser like below and also in gallon containers. I've been getting mine from Amazon.

[javadog]

Originally Posted by Baz

This stuff is the cat's pajamas. I tried it a couple years ago and now use it to clean anything that has gunky algae, mold, etc.

House
Walks and drives
Boat
Outdoor furniture
Shower/bath

I've tried all kinds of stuff but this stuff dominates!

You can buy it in a dispenser like below and also in gallon containers. I've been getting mine from Amazon.

Main ingredient, bleach!

Sodium hypochlorite, to be exact, also known as pool shock.

[A930Rocket]

Originally Posted by javadog

Watch the pressure, you can damage the brick.

This.

Originally Posted by stomachmonkey

I use a standard $10.00 1 gallon pump sprayer with a bleach solution to deal with areas like that.

And this.

[svandamme]

bleech

[Baz]

Originally Posted by javadog

Main ingredient, bleach!

Sodium hypochlorite, to be exact, also known as pool shock.

So what consumer product would you recommend?

Clorox outdoor bleach - or Pool Shock?

[911 Rod]

Are the bricks porous?
Be careful.

[javadog]

Originally Posted by Baz

So what consumer product would you recommend?

Clorox outdoor bleach - or Pool Shock?

I used both. For years, I dissolved pool shock into water and diluted it to use in cleaning winter mold off of my pool deck. Eventually I discovered I could buy dollar store bleach and do the same thing for less money. Way easier to dilute liquid bleach than it is to dissolve pool shock.

A little goes a long way.

[Baz]

Originally Posted by javadog

I used both. For years, I dissolved pool shock into water and diluted it to use in cleaning winter mold off of my pool deck. Eventually I discovered I could buy dollar store bleach and do the same thing for less money. Way easier to dilute liquid bleach than it is to dissolve pool shock.

A little goes a long way.

OK thanks - makes sense.

I just did some digging and the Clorox Outdoor bleach product (at HD) is 7.5% Sodium hypochlorite @ $7.98/gal. while the Pool Shock on the market runs 12.5% at $18.95/gal.

Just buy the Clorox product.

My Mold Armor is not supposed to be more than 5% so at ~$10/gal. I should be using the Clorox product, if trying to justify cost.

I'll try some and see if I can tell a difference.

I really like the Mold Armor though so we'll see.

[javadog]

Go down to the dollar store and buy you a gallon of bleach, for a dollar.

See how far it gets you. You might be surprised.

It doesn’t take much of a concentration to kill mold, just takes a little more time.