Bricks, Masonry, Asphalt and Concrete - Pressure-Washing and Sealing Colored Porch.

When the weather cools to below 80 I plan to power-wash and seal my concrete porch and walkway.

It is 2 years old and is stamped. The concrete had brick-red tint in it when it was wet. After 2 winters of ice and subsequent remover, some of the red tint was eaten away. I was surprised to see gray underneath.

1. What is a good quality sealer to use? It has never been sealed before.

2. I plan to rent a power washer. What solution does one use for simple dirt accumulation, and what pressure should be used?

Bump

Nobody has any comments?

I seldom pressure wash concrete and doubt I've ever cleaned any stamped or colored concrete. Usually bleach is a good cleaning agent but it might not be effective on any oil stains.

The pressure is often controlled by the tip being used. You would probably be best off with the widest tip. Check with your local paint store to find out which of their coatings would be best to use.

It sounds like the concrete was colored with color hardener before it was stamped. If the red color hardener has pitted or has otherwise delaminated, you would see the plain gray concrete underneath. First question: Have you used salt or any other ice melt product on this concrete? If not, then good for you. If so, it has caused the pitting, regardless of whether or not it says it is "safe for concrete".
As to your question: use the widest fan tip possible for cleaning normal dirt. A gas powered washer will take it off quicker, but for normal dirt an electric washer would work too. Regardless if it looks dry 2 hours later, wait a minimum of 24 hours before you re-seal. This will allow the moisture to thoroughly leave the surface, and will greatly reduce the chances of sealer failure. If you seal it too soon, the sealer can turn white due to moisture trapped under it, and delaminate quickly.
Don't use just any sealer (such as you may find at Lowes, HD, etc.) If possible, find out what your contractor used originally and try to get the same thing, or at least something compatible. The best sealer for stamped concrete, in my opinion, is a solvent-based, non-yellowing acrylic sealer of about 25-30% solids content. To make it less slippery, we add a product called H&C Shark Grip, available at any Sherwin-Williams paint store.
If you talk to your contractor about the sealer, ask him about the gray showing through. It's really a simple fix if you know what you're doing. He may be able to fix you up. Good luck.

Pecos

Hi Pecos,

Thanks for the information, especially the 25-30% info.

When the porch was poured, the entire batch was red. The porch has seen about 5 snowfalls after which I used the salt or whatever it is that is sold for ice.

Shame on me, but rather a cruddy porch than a broken leg or ankle (been there, done that, not fun) and at 63 I'd rather not take the chance. :eek: