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 $40 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.

2. 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