How To Repair Stucco On Block Wall

At showtime glance, the seamless coat of stucco on the East Boston house looked as bulletproof as a sidewalk, the perfect foil confronting the harsh wet weather condition of this littoral city. Yet below its lush cloak of ivy, the cement shell was a mess of cracks and buckling, signs that water had gotten in and damaged the underlying wood lath.

When properly installed, stucco (a cement- or lime-based plaster) is nearly as carefree and long-lived a cladding equally anyone could wish—100 years is non uncommon. Merely when big cracks or blisters appear, the time to make repairs is right away, before the harm grows.

Antonio DiSilva of MJM Masonry performed the remedial work on the East Boston house over ten days, ripping off loose fabric and patching information technology with three split up coats. Here's how to make stucco repair that lasts.

Stucco Recipes

Stucco Recipes

First glaze:

1⁄two bag (47 lbs.) Portland cement
6 shovels brick or masonʼs sand, slightly damp
one shovel hydrated lime
i⁄2 cup acrylic bonding agent

Second and finish coats:

i⁄2 bag (47 lbs.) portland cement
8 shovels amass sand for physical
1 shovel hydrated lime
1⁄2 loving cup acrylic bonding agent

Directions:

Shovel the dry ingredients into a wheelbarrow and blend them with a mortar hoe.
Add together the acrylic bonding agent, then stir in h2o, a little at a fourth dimension, until the mix reaches the consistency of buttercream frosting.
Likewise much water will make it loose and unworkable.
One time water is added, the mix will stay usable for xxx to 90 minutes before it starts to harden.

Watch The Weather condition

Freezing temperatures can ruin wet stucco. Wait for night temperatures that stay above forty degrees before tackling repairs. Hot, dry, windy weather can too interfere past sucking out moisture the mix needs to cure properly. Work in the shade so the stucco doesn't dry too fast. Betwixt coats, keep the patch moist by covering information technology with a plastic sheet.

Piece of work Safely

The alkalis in wet cement can cause burns. And then when working with fresh stucco, wear gloves or bear on the mix only with your tools, non your fingers. Keep a bucket of water nearby to launder whatsoever splashes off your pare.

Finish Information technology Right

No patch, no matter how expertly textured, will match the colour of the old stucco around it. To do that, you need to apply a pigmented blanket over the entire surface. The patch at this business firm was covered with a thick, sprayed-on acrylic elastomer that bridges and seals hairline cracks. Other acceptable coatings include physical paints and stains, mineral paints, lime washes, and "fog coats" of pigmented cement. Whichever blanket you utilise, brand sure it's alkaline tolerant and permeable to water vapor. Otherwise, it will be peeling off in no time.

Steps for Repairing Stucco

Step 1: Break Off Loose Stucco

Whack it with a hammer, or a hammer and a cold chisel, taking intendance not to harm the underlying wood board supports. Centre protection is a must.

Step 2: Chip Abroad At The Edges

Continue until you reach stucco that's firmly adhered to its lath. Cut whatever metal mesh with snips.

Step 3: Encompass The Exposed Lath

Using a utility knife, trim a piece of grade-D builder's paper to fit tightly forth the purlieus where the quondam stucco meets the exposed forest lath. Fasten the paper to the lath with roofing nails, then put a second layer of newspaper on top of the first.

Step 4: Add Mesh

Place galvanized metallic lath over the paper and trim it tight against the edge of the stucco. Snips with offset handles volition brand this job easier. Drive more roofing nails through the mesh and into the wood board.

Footstep five: Mix The Stucco

Following the first-coat recipe, stir up a batch of stucco, using a wheelbarrow as a mixing bowl. The acrylic bonding agent added to this mix improves the adhesion of the new stucco to the old.

Footstep six: Sling Information technology

Wet the border of the quondam stucco and then it won't suck moisture out of the patch and weaken the bail between old and new. Scoop fist-size wads of wet stucco onto a brick trowel and toss them against the wire board until information technology's completely covered. Smooth the mix with a finishing trowel, then pack it against the edge of the existing stucco with a brick trowel. Keep calculation more fabric until this layer is about 1/2 inch beneath the existing stucco surface.

Step seven: Scratch It

When the patch loses its moisture sheen, score its surface to improve the bond to the next coat. Tape a plastic sheet over the patch to keep it from drying out.

Footstep 8: Utilise Second Coat

Look seven days, so remove the plastic and mist the patch with water. Mix up a batch of stucco following the second-coat recipe, and trowel on a 3/8-inch-thick coat, working from the bottom up. Pack down the edges with a brick trowel. Wait for the wet sheen to disappear, and so trowel the patch shine, just below the level of the existing stucco. Encompass once again with a plastic canvas.

Step nine: Put On The Stop Coat

After three days, remove the plastic, mist the patch, and mix upward a fresh batch of stucco, following the finish-coat recipe. Different textures require different techniques. To match this wall's original "dash" cease, DiSilva scooped small globs of wet mix onto his brick trowel, then flicked them against the wall until they were flush with the old surface.

Footstep ten: Wait To Pigment

Let the patch cure for a week before painting it and the rest of the wall. Under a coat of heavy-bodied acrylic elastomer, the patch is invisible.

Tools:

Source: https://www.thisoldhouse.com/siding/21016528/how-to-repair-stucco