ADDITIONAL ASPECTS OF STUCCO

CLEAN UP PROCEDURES

 

The implementation of effective clean up procedures enhances the overall quality of a stucco application. The various stages of a stucco application commonly produce their own characteristic debris patterns. A typical lath application produces debris consisting of discarded lath components, while the debris produced by a mortar application is commonly limited to discarded mortar.

The extent of the mortar debris is usually determined by the method of mortar application. There are two basic methods of applying stucco mortar. One method involves spreading the mortar with a hawk and trowel. The other method involves dashing the mortar with a dash broom or a scoop. Although all mortar applications require the removal of any fallen mortar debris, applications that require dashing produce the additional debris caused by over-spray.

Mortar dashing applications include brocade, california, and wet dash finishes. Mortar spreading applications include the scratch coat, the brown coat, float finishes, and trowel finishes. Dry dash finishes require specific clean up and precautionary methods.

 

Useful cleaning information

Suction

Stucco mortar will generally adhere faster to surfaces providing high suction properties. See saturation, page 113.

Stucco mortar adherence to various surfaces

Stucco mortar will generally have less adherence to wood, tar, and painted surfaces, than to some types of masonry or other mortar surfaces.

Glass surfaces

It is imperative that all surfaces made of glass must be cleaned of mortar debris as soon as possible. It is also important never to use a metallic instrument to clean glass surfaces.

Cleaning grace periods

In most instances, stucco mortar is easier to remove before it sets. The one instance that mortar is easier to remove after it sets is when the adherence to the surface requiring cleaning is almost non-existent. In this instance the set mortar can be easily removed in chunks.

Lime and cement burns

Exposure to lime or cement will deteriorate your skin, and sand will grind away at the deteriorated skin. Use gloves whenever cleaning up mortar debris.

Pollution

When disposing of the stucco mortar debris, be mindful of the mortar's toxicity and ability to harden like concrete. Never dump mortar, or its ingredients such as sand, lime, or cement, into the sewers, or any other inappropriate place. Stucco mortar should only be disposed of in appropriate landfill sites.

Avoid walking over fresh mortar debris. The mortar will stick to your feet, and wherever you walk you will leave mortar ghost prints. If this is unavoidable, then a precaution such as pre-covering should be implemented over all asphalt, concrete, masonry, or wood walkways. Bystanders and animals should also be warned or restrained from walking over fresh mortar debris.

Precautions

There are a number of precautions that can help to alleviate much of the clean up requirements encountered on a mortar application. The two main criteria that determine if a particular precaution is effective are if the precaution provides adequate protection, or saves time. Whether a precaution is effective usually depends on the particular application involved.

Precautions include pre-covering areas that may become dirty, using a portable screen to deflect over spray, or saturating the surroundings with water.

1. Pre-covering

Covering surfaces prior to mortar application is the most thorough clean up precaution. Common covering materials include polyethylene plastic, paper, or tarps; secured by staples or tape.

Although pre-covering is an effective precaution, depending on the structure, it may become very time consuming to adequately implement. Consequently it may be more efficient, in certain instances, to use a different precaution or clean up method.

2. Portable screen

When the implementation of pre-covering becomes inefficient, a portable screen may become an effective precautionary cleaning method. Used to deflect mortar debris from non-application surfaces, a portable screen acts in a similar fashion to pre-covering. However, although it is not as thorough, a portable screen, as its name implies, is faster to implement than pre-covering.

3. Saturation

Saturating a surface with water annuls the suction qualities of that surface. Saturating the surroundings of a mortar application deters any fallen mortar debris from quickly adhering to the drenched surfaces. This lack of immediate adherence allows for a longer grace period before the clean up must proceed.

However, depending on the extent of the saturation and breakdown of the mortar, the extra water may eventually encourage hydration and produce stronger mortar. Therefore, the clean up should still proceed as soon as possible after the mortar application.

Whenever conditions encouraging rapid evaporation are present, it may be wise not to use saturation as a precaution. Mortar debris that dries too rapidly will not be able to hydrate sufficiently. Consequently, the resulting mortar debris becomes weak and brittle with low adherence qualities. Allowing the mortar debris to dry rapidly would assure its low strength. The low strength of the debris would contribute to easier removal. Since any moisture would contribute to the hydration process, saturation may actually contribute to the strength of the mortar and make cleaning that much more difficult.

Tools and materials used for cleaning

The tools commonly used for cleaning include old trowels and floats, mortar scoops, paint brushes, cotton cloths, buckets, muriatic acid, and a water hose with an adjustable shut off handle.

The tape used for masking should be strong enough to sufficiently adhere, yet not too strong that the adherence causes other problems. If the tape adheres too well, then its removal may also remove paint or cause other problems. Do not leave tape applied to windows or trim for an extended period of time since the tape may break down and become difficult to remove.

 

Cleaning methods

Lath

The clean up after a typical lath application involves combing the grounds and collecting any discarded lath materials.

Mortar

The most effective means of mortar removal is determined by the extent of debris and the surface that the debris must be removed from. Removing stucco mortar from the ground is effectively accomplished by smashing, while removing mortar from the structure is effectively accomplished by either the wet or dry methods.

Smashing

Breaking down mortar into its constituent materials effectively destroys the mortar's cohesion and adhesion properties. By themselves, the ingredients of mortar do not adhere well to other surfaces. The sand will sink, the cement is carried away with the water, and the water is eventually absorbed by the ground or evaporates.

Smashing is a technique used to break down mortar. Accomplished by pulverizing the mortar with a continual spray of water, smashing is only effective before the mortar sets.

The usual procedure to remove mortar from the ground is to initially remove the bulk, and then to smash the remainder. Smashing is especially effective over grass surfaces having good drainage.

Wet and dry cleaning methods

There are two methods of removing mortar debris from a structure: wet and dry. The most effective method depends on the amount of clean up required. A large amount of mortar debris will usually require the wet method, while for a smaller amount the dry method may suffice. Caution must always be exercised when cleaning surfaces prone to scratching.

Wet cleaning method

The wet cleaning method is most effective when there is a large amount of mortar debris to be removed. Proper wet cleaning normally requires two stages.

The initial stage consists of removing the bulk of the mortar debris, and then smashing the remainder. The proper result of the initial stage is an extremely thin cement film, with no traces of sand. It is not essential that this film be cleaned immediately, although it should be cleaned as soon as it is practical.

The final stage of wet cleaning involves a mixture of muriatic acid and water. This mixture is used to clean any remnants of the cement film. Muriatic acid, when mixed with water is extremely effective in breaking down and removing mortar film.

The basic procedure of acid application is to brush it on to the dirty surface, and then saturate the surface with water.

Muriatic acid, before and after mixing with water, is extremely corrosive. Always follow the manufacturer's instructions and wear the proper safety equipment when handling it.

Dry cleaning method

The dry cleaning method is most effective when there is very little mortar debris to be removed.

Absolutely no water is used. The mortar debris is wiped away with a dry cloth. The final cleaning must be made with a clean dry cloth. After the final cleaning the surface must be completely dry. Otherwise a thin film of cement will become visible when the surface becomes dry.

Since the dry cleaning method requires only one stage and does not require muriatic acid, it is both faster and safer than the wet method.

 

Typical locations that require cleaning

The grounds

The amount of clean up that the grounds of the site require depends a great deal on the current extent of the sites landscaping. If the site is fully landscaped prior to the stucco application, then the results of the clean up must be thorough to resemble the site before the stucco application. However, if the site is devoid of all landscaping, then the grounds clean up usually consists of picking up remnants of lath, large concentrations of mortar, and the removal of any obvious mess.

The structure

The locations on the structure that usually require cleaning include windows, doors, vents, lighting or electrical fittings, trim, roofs, soffits, decks, and foundations. Each location presents its own characteristic cleaning requirements.

 

Cleaning various surfaces

Cleaning glass

The clean up of glass surfaces must be performed almost immediately after the mortar application. Never use sharp or metallic objects to clean glass. Precautions, such as pre-covering or saturation, should be considered prior to mortar application.

The most effective clean up method for glass surfaces depends on the amount of the mortar to be removed. If there is very little mortar then use the dry cleaning method. Otherwise use the two staged wet cleaning method.

Cleaning wood

The proper method of cleaning wood depends on whether the wood is bare, painted, or treated, and the amount of mortar to be removed.

Since wood exhibits high suction properties, any mortar contact will usually leave a mortar stain. Whenever wood must not be mortar stained at all, such as when the wood will remain untreated, or is intentionally color stained, the precaution of pre-covering must be utilized.

Wood that will be painted should be primed before the first mortar application, and the final coat of paint should be applied after the final stucco application. The initial priming coat will protect the mortar from stains caused by the wood. The final coat of paint will cover any mortar stains resulting from the stucco application.

Cleaning on asphalt, concrete, and masonry surfaces

Upon contact, stucco mortar will almost immediately stain asphalt, concrete, and masonry surfaces. Consequently, precautions must be taken to assure that no mortar debris remains on these surfaces.

The most thorough precaution is to pre-cover the surfaces prior to mortar application. However, if pre-covering is not an option, then use the saturation precaution, and continually keep the surface wet until it can be cleaned.

Cleaning on dirt or gravel surfaces

Upon first thought, mortar clean up on dirt or gravel surfaces seems like a straight forward proposition. However, unless the resulting appearance is unimportant, such as before landscaping, cleaning on dirt or gravel surfaces can produce cleaning nightmares.

Unlike smooth hard surfaces, dirt and gravel consist of many small materials. To completely remove all traces of mortar usually requires the removal of all of these small materials.

Usually what happens is the mortar debris is not completely removed. In this case the mortar will usually create visible stains.

Cleaning on grass surfaces

Clean up on grass is usually very easy. After any excess mortar is removed, the remainder can be smashed into the grass.

If you have very little stucco mortar to clean up, one easy trick is to clean up on a grass surface. Since cement floats on water and sand sinks, the cement will tend to stick to the grass blades while the sand sinks. The next time the grass is mowed the remnants of the cement are taken away with the clippings.

Cleaning surfaces made of tar

Surfaces made of tar, such as tar decks, usually do not provide very good adherence to mortar. This is especially true if the tarred surface is extremely smooth, providing minimal means of mechanical bond. This fact, combined with the fact that mortar adheres well to itself, enables the use of special cleaning techniques.

Any stucco mortar that lands on a smooth tar surface can remain undisturbed for hours without any negative effects. As the chunk of mortar sets, its cohesion properties increase. When the mortar's cohesion properties are greater than the adherence properties exhibited between the tar and the mortar, then when the chunk of mortar is removed all traces of mortar will adhere to the chunk.

This technique provides time for the correctly applied mortar to set, prior to clean up. This reduces the chance of damaging the application when cleaning. Another advantage of this technique is the clean up does not have to be performed immediately but can be postponed until a more convenient time.

Cleaning off tools

After each stoppage in mortar application, a thorough cleaning of the stucco tools is critical. If the mortar is not completely removed from the tool then it will increasingly continue to build up over time. This mortar build up may affect the application qualities of the tool.

Since any damage to a stucco tool may affect its application qualities, no excessive force should be used to clean a stucco tool.

Before cleaning the hawk, remove the hawk's doughnut sponge, and try not to get the hawk's doughnut sponge wet.

Lightly grinding the tools in uncontaminated sand is an effective way to remove mortar remnants.

Do not clean off any tools over asphalt or concrete surfaces, instead, clean off the tools into a wheel barrow or over dry grass surfaces.