Sandstone pavers are very porous in nature, which makes them very easy to stain and difficult to seal. When you want to build a patio using sandstone pavers then you need to seal them before and after installation. The article that follows will explain how to properly seal sandstone pavers.
Step 1 – Cleaning the Sandstone Pavers
When you set out to seal sandstone pavers you need to make sure that the pavers are free of dust and oils. Sealing an unclean paver can leave a bad finish, or an incomplete seal. Mix several drops of oil-free detergent in a bucket, and add warm water. You want the water to be sudsy. Dip the scrubbing brush in the water, and scrub down each of the sandstone pavers. Allow the soapy water to remain on the pavers for about 30-minutes, and then rinse them off with clean water. Allow the sandstone pavers to dry, before continuing forward.
Step 2 – The Initial Sealing
Sandstone pavers can become stained really easily, due to the porous nature of the sandstone. If you spill oil or grease on the sandstone, it will be absorbed by the sandstone, and remain visible on the surface. When you purchase the sandstone pavers, prior to installing them is when you want to clean and then seal them. Due to the porous nature of the sandstone, use a sealer that is deep penetrating. Pour the sealer in to a clean spray bottle, and then spray the sandstone pavers down with it. Wait a few minutes, and then wipe them down with a dry sponge. Repeat this process one more time, allowing the sandstone pavers to dry overnight.
Step 3 – Installation
Once the sandstone pavers have been sealed, they can be installed in the prepared area. Place the pavers in the site, making sure they are seated properly. Pour the sand on top of the pavers, and push it around with the broom to fill the joints. Hose it down and then add more sand. Continue in this manner, until all the joints are completely filled. Do not continue on until the sand has dried. You can also use grout to fill the joists.
Step 4 – Second Sealing
The initial sealing will protect the sandstone pavers from being stained by the grout or sand you employ to seal the pavers. Once the sand or grout has completely dried, you can then seal the sandstone pavers again. Using a spray bottle is a process that can take a lot of time. Pour the sealer in to a clean bucket, and then use a mop to spread it out over the sandstone pavers. Allow the sealer to dry overnight, and then apply a second coat of the sealer in the same way.
selected from: https://www.doityourself.com/stry/build-stone-porch-steps-in-5-steps