1 Total costs (materials plus shipping and labor) for installing a straight, return or L-shaped stair can run $1,300-$7,000 or more. 2  Materials plus labor for custom-built wooden stairs, such as a sweeping circular or elliptical design, can cost $10,000-$30,000 or more, depending on the size, style and type of wood.
Make another bleach solution and pour it onto the driveway. Wait 20 more minutes for the bleach to kill the mold. Rinse the driveway thoroughly with a garden hose. Prevent future mold with a borate solution. Mix 1/4 cup of borate detergent with 1 gallon of warm water in a bucket. Pour the solution onto the driveway and allow it to dry. Don't rinse it.
1 Mix 1 cup of bleach and 1 gallon (3.8 L) of water. 2  Use a spray bottle or a bucket and sponge to apply the bleach mixture to the area with black mold. 3  Let the bleach sit on the mold for an hour.4  You can wipe it away later if that is your preference, but this isn't necessary. Mix 1 cup of bleach and 1 gallon (3.8 L) of water. 2  Use a spray bottle or a bucket and sponge to apply the bleach mixture to the area with black mold. 3  Let the bleach sit on the mold for an hour.