Saturday, January 27, 2007

Cleaning Concrete Pavers

Concrete pavers are routinely specified for roofdecks, terraces and backyards. While they are long-lasting and relatively cost effective, they are also porous and require maintenance. Rust, grease, wine, white residue, dirt/soot, and mold stains on your pavers will ruin the look of your garden space. (Photo above shows pavers being installed.)

Some professionals recommend sealing the pavers to reduce dirt & grease absorption. We have never found a sealer that lasts longer than a year, in spite of claims by various manufacturers. Application and re-application can become very expensive (depending on the size of your roof area -- between $1500 to $2500 + per application).

We have also tried many cleaning products costing from $20 to $200+ but have never found a product better than baking soda and a mild solution of bleach.

Concrete pavers come in many colors and are made by adding pigment to the concrete mix during manufacturing. This means that the color runs thru the entire paver and is unlikely to lose color during cleaning. **But please do a test cleaning on a paver before you do your entire roof surface.

What you will need:
5 gallon bucket of water with 1/2 cup of bleach
Baking soda
Long handled stiff bristled plastic scrub brush (do not use a metal brush).

Sprinkle a liberal amount of baking soda onto pavers;
dip brush in bleach solution and scrub in 8' x 8' sections; allow to sit on entire surface area for a few minutes, then rinse thoroughly. Although you can definitely spot clean a paver, it is better to clean the entire roof surface -- or large areas at a time -- to avoid variation of look from section to section.

To avoid bleach splashing onto your pots & planters, place a large (opened) cardboard box upright against each planter. Scrub/rinse, re-place the cardboard against next planter.

For your information: The rust is caused by the iron oxide minerals in the paver combined with water -- and the metal railings, furniture and fixtures in your garden. The white residue, called efflorescence, is the lime released within the concrete carried by water to the surface of the paver.

Never use acid cleaners on your pavers.

Clean grease stains immediately. Wipe off excess oil; apply detergent and allow it to sit for 10 minutes; then wash with hot water. If there is still a stain, scrub with bleach and baking soda. Never use amonia and bleach together; the fumes caused by this combination are dangerous to inhale.

Do not use this cleaning method on granite, marble, or other natural stone products. These products can be fragile and require a professional stone cleaner or restorer.

NEXT POST: Roof gardens and weight allowances
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Anonymous said...

People should read this.

Anonymous said...

ha, I will try out my thought, your post get me some good ideas, it's truly amazing, thanks.

- Murk