How to Repair Crumbling Cement Walls

Aerated Concrete Block Disadvantages
Published: Apr 23, 2010
Updated: Nov 20, 2021
2 minute read

Once you have been assured by an expert that the entire wall does not need to be rebuilt, you can use a few simple supplies and some easy steps to make your wall perfect again in just one long weekend.

Things You Will Need

  • Protective clothing
  • Steel-toed boots
  • Goggles
  • Work gloves
  • Stiff-bristled brush
  • Paintbrush
  • Cement blocks
  • Scrap lumber
  • Cement patch product
  • Bucket
  • Shovel
  • Garden hose with fine mister attachment or fine misting spray bottle
  • Metal trowel
  • Heavy plastic wrap
  1. Wear appropriate clothing that will protect your skin from flying cement. Completely cover your limbs and choose thick or steel-toed boots to guard your feet against falling pieces of cement. Wear goggles to protect your eyes and work gloves to protect your hands.

  2. Scrub the crumbling areas of the wall gently with a stiff-bristled brush to knock away small, loose pieces of cement. Use a clean paintbrush to make sure that the entire area is free of cement dust and other debris.

  3. Place two large cement blocks tightly against the wall underneath the area to be patched. Lay a scrap board over the blocks to provide a surface that will catch any cement patch that falls so it can be scraped up with a trowel and reused, rather than ruining the surface below the wall.

  4. Transfer the dry cement patch product to a bucket and add the amount of water indicated on the package. Mix with a shovel until the consistency is a bit looser than toothpaste.

  5. Dampen the area that you want to patch using a garden hose with a fine-mist attachment or a fine-misting spray bottle.

  6. Add a generous application of the prepared cement patch to the crumbled area with a metal trowel until the patch is built up evenly with the undamaged wall around it. Carefully smooth the surface of the patch with the flat face of the trowel. Turn the trowel to a 45-degree angle and use the edge to scrape away excess patching material. Allow the patch to cure for two hours.

  7. Pat or rub over the set patch material with a scrap piece of lumber so that it has a similar texture to the older cement and does not stand out.

  8. Repeat the process to fill other crumbling areas. Cover each patch gently with heavy plastic wrap and allow to cure for three days before removing the plastic.

The Drip Cap

  • Many garden and boundary walls are created using inexpensive cement blocks.
  • Completely cover your limbs and choose thick or steel-toed boots to guard your feet against falling pieces of cement.
  • Lay a scrap board over the blocks to provide a surface that will catch any cement patch that falls so it can be scraped up with a trowel and reused, rather than ruining the surface below the wall.
  • Carefully smooth the surface of the patch with the flat face of the trowel.
  • Repeat the process to fill other crumbling areas.

Photo Credits

concrete wall image by bayu harsa from Fotolia.com

concrete wall image by bayu harsa from Fotolia.com

Jourdan Townsend

Jourdan Townsend has been writing since childhood. Her articles appear in a collection of student works at the University of Oklahoma as well as in the school's "Honors College Journal." Townsend also composes poetry, some of which can be…

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