How To Repair Stucco

exterior stucco toronto

Stucco and stucco siding is used in home design to incorporate and add flare to walls, ceilings and doors. Stucco installation and application is usually completed by a professional. Thanks to wear and tear and a lack of stucco maintenance throughout the years stucco can sometimes be in need of repair. Stucco is known as one of the most durable wall surfaces available in design and construction, but because of its particular nature, stucco can often develop cracks and holes over time and require repair. Unlike other home building materials, cracks in stucco should not be painted over or quickly filled in as some homeowners believe is the solution.

Many homeowners with homes that require stucco repair look toward a do-it-yourself path. Before the panic sets in, take a brief look at the 10 simple steps it takes in repairing stucco.

Tools You Will Need

Stucco Installation by Exterior by Design

In order to repair a stucco/stucco wall a homeowner will require the correct tools. This is what is needed:

  • Five-gallon bucket
  • Stucco mesh/stucco wire/stucco patch aka stucco lath
  • Mason’s chisel
  • A hammer
  • Water
  • A hoe
  • Premixed stucco or a patching compound (optional method: mix your own stucco mix*)
  • Notched trowel
  • Work gloves
  • Eye protection (goggles)
  • Ladder
  • Paint
  • Plastic covering
  • Wheelbarrow
  • Plaster finishing trowel
  • “A Finishing” tool (such as a whisk, sponge, or a piece of board)
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*to create a custom mix:

  • Step 1: Pour one five-gallon bucket of fine clean sand into your wheelbarrow.
  • Step 2: Dump a gallon of hydrated lime into your wheelbarrow. DO NOT BREATHE IN THE CHEMICALS.
  • Step 3: Add about a quart of the Portland cement and mix the dry mixtures together with your hoe.
  • Step 4: Slowly add water and mix.
  • Step 5: Keep the mixture damp with water.

Note: In a two-coat application, the brown coat is eliminated and the finish coat is applied directly to the scratch coat.

Steps for Repairing Stucco

Exterior by design team in progress of exterior stucco repairing

Now that the correct tools and materials have been acquired and the stucco mix has been purchased or created it is time to start the repairs.

Step 1: Begin By Breaking Off The Loose Stucco

Removal of the loose stucco is needed to complete stucco crack repair. Smash it off with a hammer,or the combination of a hammer and chisel. While doing so be sure not to damage the underlying wood lath supports or risk further house/foundation damage.

NOTE: Eye protection is a must in this step.

photo of a team cleaning street with water pressure

Step 2: Continue To Chip Away At The Edges

Continue the removal of the loose stucco by chipping away at the edges. Cleaning up the debris as you go is a good idea.

photo of wall painting

Step 3: Cover The Exposed Lath Of The Area

Using a utility knife or exacto knife trim a piece of paper from the materials purchased to cover the area where the lath meets the wall. Next, fasten the paper securely to the lath with roofing nails, then apply the second layer of paper on top of the first layer of paper.

photo of a mesh

Step 4: Add Mesh

Place a metal lath or sheet over top of the paper and trim it tight against the edge of the stucco using a utility knife. Next, drive more roofing nails through the mesh and into the wood lath securely.

photo of pre-mixed stucco

Step 5: Mix The Stucco Or Gather pre-mixed stucco

Following the provided stucco recipe, or making use of pre-purchased-premade stucco.

photo of cleaning floor

Step 6: Start To Sling It

Wet the edge of the old stucco so it won’t absorb moisture out of the patch and weaken the created bond between the old and new stucco. Scoop fist-size wads of wet stucco onto a brick trowel and toss/place them with force against the wire lath until it is completely covered. Smooth the stucco mix with a finishing trowel, and pack it against the edge layer of the existing stucco with the brick trowel. Do this until it is about ½ thick.

photo of exterior house before applying stucco

Step 7: Start To Scratch It

When the patch fully loses the wet sheen look egin to score its surface to improve the bond to the next coat, this is very important. Tape a plastic sheet over the patch to keep it from drying out and needing to repeat this step.

stucco by the entrance

Step 8: Applying The Second Stucco Coat

Waiting at least one full week for the first coat to dry it will then be time to apply a secondary coat. Pack down the edges with a brick trowel once again and wait for the wet sheen to disappear, then back at it with the trowel and the patch smoothing, just below the level of the existing stucco applied prior. Following by covering again with a plastic sheet.

exterior by design team finishing exterior stucco

Step 9: Apply The Finish Stucco Coat

Waiting three more days remove the plastic sheet, then mist the patch, and gather your pre-mixed stucco or mix up a fresh batch of stucco, following a finish-coat recipe.

Note: different textures require different techniques.

exterior stucco overview

Step 10: Wait To Paint (Yes, more waiting)

Allow for at least one week for the patch to cure before painting. Make sure that everything is dry and then paint your desired colour.

It is very important to correctly complete stucco repair. Patching or painting your stucco can be very dangerous and costly if done incorrectly. In doing so, it may lead to structural damage and very expensive repairs that homeowners are unable to mend using this DIY tutorial. For further tips and tricks it may be beneficial to contact a professional to complete this repair project. And always remember to maintain safety precautions when performing home repair projects without the supervision of a professional.

Following these 10 steps it will be time for the bonus step, enjoy the fruits of your labour and show off your hard work to friends and family. Happy stucco-ing!

RELATED ARTICLE: Stucco Maintenance Guide