How to Seal Exterior Stone Siding

A home with stone siding.
  • 5 hours
  • Advanced
  • 500-1,000
What You'll Need
Long-handled nylon brush
Buckets
Warm water
Natural stone cleanser
Stiff-bristled brush
Garden hose, with spray attachment
Old towels
Oxygen bleach
Sponge
Natural stone sealant
Paint roller
Paintbrush
Pan
Soft cloth
Dust mask
What You'll Need
Long-handled nylon brush
Buckets
Warm water
Natural stone cleanser
Stiff-bristled brush
Garden hose, with spray attachment
Old towels
Oxygen bleach
Sponge
Natural stone sealant
Paint roller
Paintbrush
Pan
Soft cloth
Dust mask

Exterior stone siding can add charm and elegance to your home. It also gives your home a high level of protection against the elements. When well maintained, the siding adds value to your property. It is vital that you seal your siding during installation to help protect its integrity. Thereafter, you need to apply a stone sealant every one to two years. It is best to apply sealer during hot weather so that it dries properly. This can be done with the help of the guide below.

Step 1 - Brush off Surface Dirt

Wear a dust mask to prevent inhalation of dust. Use a long-handled nylon brush to clear away surface dust and dirt from the siding. It makes it easier to wash the siding once you reduce the dirt.

Step 2 - Wash the Siding

It is vital that your siding is cleaned thoroughly before you apply the sealant. If you apply the sealant onto a dirty surface, it traps the dirt underneath. This causes a residue between the stone and sealant, which reduces the aesthetic appeal of your siding. Mix some warm water and natural stone cleanser in a bucket. Dip your brush into the water and give the siding a good scrub. Begin from the top, as you work your way across. Steadily move downwards until you’ve cleaned the entire surface.

Step 3 - Rinse

Attach the spray fitting onto your garden hose. Use the hose to wash away the soapy water from the siding. Spray from the top as you work your way downwards. Use an old towel to wipe away water from the siding. Allow two hours for the stone to dry completely.

Step 4 - Remove Stains

You may notice some stains on the siding after you’ve dried it. It is a good idea to clear these stains before you apply the sealant. Mix 1 cup oxygen bleach and 2 cups water in a small bucket. Saturate a sponge with the bleach solution and apply to the stains. Allow about 10 minutes for the bleach to clear the stains. Apply some more bleach solution and scrub the stone with a brush. Use your garden hose to spray water onto the stone. Dry the area with an old towel, then allow two hours to air dry.

Step 5 - Apply Sealer

Obtain a natural stone sealant, for exterior use, from a home improvement store. Pour some sealer onto a pan for easier application. Work in the same pattern as when you brushed and washed the siding. Wet your roller with the sealer. Use up and down movements to apply a thin coat of sealer onto the siding. For areas that are difficult to reach, apply the sealer with your paintbrush. Use a soft cloth to wipe away excess sealer so that you avoid streaks on your siding. Wait the required time before you apply another coat.