Concrete Deck Repair Guide

What You'll Need
Clean, empty bucket
Wheelbarrow for mixing the concrete
One bag of Portland cement (20- or 50-lb., depending on the repair area size)
Sand and fine gravel to make enough concrete for the patches, as explained below
Rent a cement mixer and operator for the day, if you prefer, and use a ready-mix concrete blend
1-cup (8-oz.) scoop
4-inch paint brush
Flat, rectangular trowel for smoothing
Long metal stick for stirring
Broom, mop and separate bucket of water
Acrylic bond mix, if preferred (1 liter covers 10 square feet)

A concrete deck repair, done correctly, can add up to 30 years to the serviceable life of your deck. The key to a successful and permanent concrete deck repair is the strength of the bond between the new and old concrete. You need to add an adhesive to the surface. Traditional cement adhesives and new acrylic bonds work equally well. Wait 30 days after concrete deck repair to apply concrete deck paint, if desired. Complete repairs on a cool, overcast day. Too much sun will prevent effective application of the adhesives to the concrete.

Step 1 - Choose the Kind of Adhesive You Want to Use

Acrylic bond mix is semi-liquid and comes ready to apply. Portland cement paint must be mixed by hand.

Step 2 - Clean the Surface to Be Repaired

Sweep diligently to remove all loose stones, debris and dust. Wash the surface and remove any greasy spots. Rinse the concrete deck with water and leave it slightly damp.

Step 3 - Prepare the Concrete

In the wheelbarrow, mix up the Portland cement, sand and gravel as follows: one part cement, two parts sand and three parts gravel. Add just enough water, in small amounts, to make a putty-like mixture. If you don't want to mix your own, rent a cement mixer with an experienced operator for the day. You will need to cover all material quantities and costs.

Step 4 - Apply the Adhesive

  • Option 1, Portland Cement: In an empty bucket, blend 2 cups of Portland cement until well mixed to the thickness of pancake batter. Spread it with the paint brush over the whole area to be patched. Smooth it with the trowel. Apply the concrete on top of the adhesive immediately.
  • Option 2, Acrylic Bond Mix: Pour the acrylic bond mix from the container onto the repair area. Smooth it out with the trowel. It will go on white and opaque. When it has dried to a clear transparent finish, apply the concrete.

Step 5 - Put on the New Concrete

Distribute the concrete over the area coated with adhesive. Smooth it evenly and quickly with the trowel. Avoid the area until it's fully dry, and finish with a sealant after 72 hours.

You can complete most concrete deck repairs yourself. However, consult and hire a professional to reattach stairs or replace broken corners of decks or slabs.