Paver bricks: removing stains and replacing sand between joints

[Ray Kostanty]

1. My new (2 months old), still-unsealed concrete paver bricks (Cambridge brand with Armortec)have stains on them from where leaves were laying during a rain storm. Any cheap way to remove them? I know there are solutions that cost per gallon. I've tried bleach and laundry detergent with a scrub brush. (The stain didn't come out, but the rest of the paver was cleaner.) Haven't tried TSP yet.

1. The house is built on a slab on clay soil. Some of the pavers abut the foundation walls, and there is sand between the pavers and the wall. Would it be better to replace the sand near the walls with something waterproof, to minimize moisture getting under the foundation where there may be freeze damage?

Before installing the pavers, there was a concrete patio slab with a

1/2-inch gap between the slab and the walls. Since the house was built in 1969, one corner of the patio slab had sunk at least two inches, so rain ran toward the foundation walls. Despite that, there is no sign of freeze damage over the 35 years. The new pavers are properly pitched away from the walls, but they have many more entry points for water (between each joint) compared to the solid concrete slab.

Thanks,

Ray

[Will Niccolls]

"Ray Kostanty"

Last fall leaves stained my paver driveway. As you described, stains appear when the leaves get rained on and plastered to the surface. I did nothing, and by April this year the stains were gone, washed away by snow and rain. This fall I'm sweeping the leaves off.

I'm not positive that the PavePrep or other acid cleaners would remove the leaf stains. Time will, though.

Depending on the construction details, you could put a piece of L shaped flashing up under your siding, lapping over the pavers. Or, you could use some elastomeric caulk to try and seal the joint. Or, you could remove the existing sand and replace it with some polymeric sand, which allows less water to penetrate.

In any case, if the pavingstone surface is correctly pitched to shed water, you will have little water penetrating the area. Properly installed pavingstones shed 90% of the surface water. The joint at the foundation is more vulnerable but in most cases isn't a problem.

Even though they have more joints, they still shed the great majority of the water. What water does permeate the pavingstone surface under most conditions disperses through the drier base and soil without harm. Assuming the pavinstones were installed properly, and that you have proper drainage elements in place in adjacent areas, you should be fine.

Will Niccolls ICPI Certified Installer

[Ray Kostanty]

Thanks, Will, for the encouragement regarding the leaf stains and the suggestion for polymeric sand; sounds like just the thing I need. In my situation, flashing won't work.

Ray

Will Niccolls wrote: