How to Repair a Sagging Concrete Garage Floor

Concrete is one of the most popular building materials available today. Made from a blend of Portland cement, water and sand, this material is known for its affordability, versatility and strength. Concrete is commonly used to build walls, foundations and floors. Though it is relatively easy to work with, this material requires a basic level of skill and preparation to ensure a successful installation. When it is improperly installed, concrete can suffer from cracks, holes, and worst of all, sagging. To repair minor sagging issues, a self-leveling compound can be applied to the surface. This project can be completed by the average homeowner in just a few hours.

Things You'll Need

• Portland cement Water Bucket Trowel Expansion tape Self-leveling concrete Drill with paddle bit Wheelbarrow Concrete rake

Instructions

1. Mix Portland cement and water in a bucket. Add only as much water as directed on the cement package. Blend thoroughly.

2. Use a trowel to fill any cracks or holes in the existing concrete with your Portland cement mixture. Wipe away any excess material, then allow it to dry completely before proceeding.

3. Apply a layer of expansion tape around the room's perimeter. This tape will act as a dam to hold the topping layer in place, and will keep it from damaging your walls or baseboards.

4. Blend your self-leveling mixture with water per the instructions on the package. The material can be blended in a wheelbarrow or bucket using a drill with a paddle bit.

5. Pour the self-leveling mixture onto your floor, working in 1- to 2-foot-wide sections. Spread the material across the surface using a concrete rake. Gravity will distribute the material across the floor to cover the sagging sections.

Tips & Warnings

• To add a protective waterproofing layer, apply a concrete seal to your floor after the leveling compound has dried.

• If your garage floor sags more then a couple of inches, consult a professional to prevent structural damage to your walls and foundations. They can inject additional fill material under your floor to fix the sagging.