Sealing concrete

LAST UPDATED: 8th January 2023 by The Editorial Team

Sealing concrete

Summary: Step by step guide and video showing how to seal concrete, prepare the surface and apply sealant to protect the concrete surface from weathering.

How to seal concrete

Sealing concrete is necessary if you want to prevent the access of water into the pores of a concrete surface. Usually a sealer is required in newly laid concrete, which will give it an attractive finish as well as suitable protection from the elements.

  • Firstly you will need to clean the concrete surface in preparation for the sealer. A quick and effortless way of doing this is to use a power-washer. This will clear away most of the dirt using a powerful jet of water. Alternatively you can use a scrubbing brush and lots of water.
  • Once the initial removal of dirt is complete, you will require a cleaning agent that can remove grease and oil stains, plus other tough grime. A cheap alternative to buying a cleaner is to use a 1:1 mix of water and bleach.
  • When you have finished using the cleaning agent, wash away all residue thoroughly and allow the concrete surface to dry properly.
  • When purchasing the sealer, you need to know which type to go for and the amount you will need. Read the bottle information to decide if it is appropriate for your needs. When deciding on quantity, measure the height and width of the surface area you will be sealing and multiply the figures. Go to a hardware or DIY store to purchase the product, where help is available should you need it.
  • There are two main types of sealer; film former and penetrates. Film former sealer is mainly used for the attractive glossy finish, whereas penetrates soaks into the concrete and leaves a matte finish. Both are equally water resistant.
  • Once the surface is ready to be sealed, apply the sealer onto the concrete and spread evenly using a roller. Apply two coats if necessary and leave to dry before using the concrete surface.

How to seal concrete video – part 1

Summary: DIY video showing you how to clean concrete in preparation for the sealer.

Types of concrete sealers video – part 2

Summary: DIY video showing you how to choose which type of sealer to use on concrete.

Applying concrete sealer – part 3

Summary: DIY video showing you how to apply concrete sealer.

Sealing concrete will help protect it against the weather as well as oils and grease. Sealing a newly laid concrete driveway will also give it an attractive finish.

Author

The Editorial Team

The Editorial Team at lets-do-diy.com are a team of experts led by Mark Wilson. We have been creating DIY projects, articles, costs guides and product reviews since 2008. For more info see our about page.