Stucco Parapet Repairs

Welcome.  The Stucco Repair page on this website goes into detail regarding stucco types and how various paints affect it.  That information presented there carries forward to Stucco Parapet Repairs.

Stucco Parapets are a magnet for cracks.  Being on top of the roof they are in the sun for far more time than any other parts of the house.  In the sun longer means they get hotter.  Ironically at night they also get colder since the roof is also the coldest part of your home at night.  Being the hottest and coldest the parapets experience a great deal of movement from the daily heat cycle caused by the sun.  More movement means more cracking.  Hotter also means the paint dies sooner.  More cracking and more dead paint means more places for water to get in.

 

The crack shown in the photo below is an example of a typical crack in a stucco parapet.  Patching this and coating it with elastomeric rubber paint is pretty straight forward.

Parapet2

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In the past few years a fairly large percentage of the calls I receive about bad parapets are related to what I believe is bad Chinese galvanized metal imported around ten to fifteen years ago and used to as an underlayment for masonry stucco.    If you’d like to read more about this the following two links are a place to start.  If you want to skip the articles – they say the galvanized metal which most people think of as rust proof or seriously rust resistant are in fact not.

Chinese Steel Sheets Fail Product Test

Galvanized Pipe Section of this article

Good news.  Its not hard to tell when rusty metal mesh  is involved in parapet cracks.  As mentioned the above picture is a “normal” crack in a parapet.  The picture below is a cracked parapet with failed metal.  Failed in that it no longer exists.  There is supposed to be a metal mesh like chicken wire in this crack.  You can see a little bit of whats left  by the letter “m” in AABrite.com

Parapet (1 of 1)

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So to paraphrase so far.  Regular parapet cracks – easy and not so expensive to fix and paint.   Bad Chinese metal parapet cracks – more work and more expense to fix and paint.

A little more bad news about the Chinese failing metal.

If you have the bad Chinese metal you also need to know after getting it repaired, patched and painted there is very likely going to be a second outbreak on the parapets at some point in the future.  The mesh is pretty important for keeping the stucco from getting big cracks.  When repairs are made we cut out the bad sections we can feel.  They have a hollow sound when you tap on them and there’s some movement.  After the patches are complete, some more of the metal is going to give way (fail).  It will then take a while, as in months to years, for these smaller unknown areas to finish rusting and to crack out.  In 12 years I’ve never seen the second round go over 10% of the size of the first patch.

The most important part of owning a home or building with stucco parapets is to keep a good healthy coat of roof coating (called elastomeric) on the tops of the parapets.  This helps two ways.  Elastomeric acts like fat rubber cement and helps hold everything together and secondly its highly water resistant.  No water, no rust.  If you stop the rusting then the stucco can stay strong.

Now if your worried about the metal mesh failing in the stucco walls and making bigger problems, I’ve never seen or heard of this happening.  The parapets are where the issue is based on my experience.  BUT if you get a leak around a window – get it taken care of as soon as you become aware of the problem.  Letting it go will allow water to get into the metal and start rusting it in the wall.

Our Process

I inspect the parapet and determine how many feet of stucco are going to be removed and replaced.  The price is based on how long a job is expected to take and how much material its going to be required.  One stucco bag is only going to fill one cubic foot on average.  As an example a 5,000sq/ft house with failing chinese metal on lots of parapets could take 100 bags.  From my perspective thats a big job, though wether its 5 bags or 500 the work is the same.

Based on my price calculations a homeowner will have to decide how much paint work is going to be allotted to the job.  I much prefer to paint the entire home after parapets are repaired since this is gives me the most control and the least amount of  with regards to paint, texture and blending.  Painting the entire house is not always an option, then we have to agree on what smaller parts are getting painted since from the ground different parts of the parapet will be visible.   This is done on a case by case basis.

After agreeing on price and scope of the paint work we are ready to start.

We break out the loose parapet stucco with a hammer.

Parapet (1 of 1)-2

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Galvanized metal mesh is installed as needed and attached with nails.

Parapet3

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The hole is filled and the parapet is roughly shaped with a rubber sponge float.  The first layer of stucco fill is allowed to dry out.  When it drys it will shrink some and crack around the edge of the patch.  A second layer of stucco is then put over the patch.  It too will shrink, but much less than the first coat.

Parapet-113503

The third coat is worked over with a wet sponge float and the texture is scrubbed up.  There is some art work involved here with matching the existing texture.

Parapet-6935

We have screens for separating out specific sizes of sand to add to the stucco the match the existing texture the best we can.

The texture is wet down to slow the drying process and avoid cracks.  The water also lowers the PH if masonary patching compound is used.  Synthetic compounds don’t need to  have the PH lowered.

If a masonary compound was used we then put on Eff stopp primer – to stop the high PH masonary from attacking the new paint.

Rubber elastomeric paint is then put on the top of the parapet.

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Armando

 

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Before parapet repairs, painting and roof coating

Parapet-6922

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After  parapet repairs, painting and roof coating

Parapet-7098

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Before parapet repairs, painting and roof coating
Parapet-6923

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After parapet repairs, painting and roof coating

Parapet-7097.

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