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Stucco Colors and Stucco Textures

Condition Troubleshooting Menu

Technical Bulletins

Failure to mix colour coat properly
Pigment Migration
Uneven Drying of Colour Coat
Addenda
Colour Contamination
Visible Joint & Scaffold Marks
Stains
Colour Correction

TB001-Hoarding Stucco Work
TB002-Cold Weather Application
TB003-Cold Temperature and Acrylic Stucco
TB005-Effects of Suction
TB010-Fastening Stucco Wire
TB011-Building Paper and Wire
TB012 Soffits-Direct Application
TB014-Soffit-Portland Cement Plaster
TB030-Exterior Stucco Use
TB031-Polybase over Paint
TB040-Colour Stability Tech Article
TB041-Interior Acrylic Use
TB050-Artisan Application
TB060-Efflorescence
TB062-FogCoat
TB100-Maintenance and Cleaning

Condition:
Non-uniform suction of the basecoat

	Cause		Prevention
1.	Difference in thickness of basecoat plaster.	1a.	In line wire construction, care in lathing is required to provide a taut, straight base so that plaster may be applied to a uniform thickness. Inward deflection of backing between framing members should be kept to a minimum.
		1b.	Framing members should be aligned so the plaster membrane will be of uniform thickness while achieving a straight true surface.
		1c.	Properly installed exterior sheathing, masonry, or concrete should provide a straight base for plaster of uniform thickness.
2.	Over spray of extraneous material such as paint, gypsum plaster, sealants, etc.	2a.	Each coat of plaster must be kept clean of any materials which affect suction or density.
3.	Unequal water ratio in successive batches.	3a.	Mix batches to uniform slump.
4.	Failure to maintain mix proportion of aggregate or cement.	4a.	Maintain uniformity of ingredient proportions.
5.	Changing brands of cement with a panel or wall.	5a.	On each panel or wall use a single brand of cement.
6.	Unequal proportions of lime or approved admixtures in successive batches.	6a.	Maintain uniform proportions of lime or approved admixtures.
7.	Failure to off-set joinings in scratch and brown coat.	7a.	Joinings in brown coat should not occur at same place as joinings in scratch coat.
8.	Cold joints in brown coat.	8a.	Apply brown coat in continuous operation over entire panel or elevation, making any necessary stops at architectural breaks.
9.	Rodding or darbying at improper times.	9a.	Standardize delay time adjusting for prevailing job conditions before leveling.
10.	Over-floating the brown coat, or floating too soon.	10a.	Brown coat must be uniformly floated at the proper time of take-up with uniform pressure.
		10b.	Glazed spots (floated wet) should be re-floated as the brown coat takes up.
11.	Irregular floating caused by different materials of which floats are made.	11a.	Use similar facing materials for all floats used on the brown coat.
12.	Dry rodding only some areas of brown coat.	12a.	Surface must be uniformly rodded.
13.	Uneven drying.	13a.	Allow the brown coat to dry for five days after proper curing, longer if necessary in judgment of plastering contractor. NOTE: Relatively longer drying is necessary: (1) when asbestos fibre is incorporated in scratch and brown coats as with gun applied plaster. (2) under unfavourable climatic conditions.
14.	Freezing or seriously retarded hydration due to low temperatures	14a.	Damp cure above 40� until plaster hardens, or apply an approved curing compound that will not adversely affect the brown coat.
15.	Non-uniform dampening of brown coat.	15a.	For floated or textured finishes, dampen each elevation uniformly, if conditions warrant.

Condition:
Failure to mix colour coat properly

	Cause		Prevention
1.	Improper proportions.	1a.	Insist on proprietary factory-mixed coloured stucco, insuring uniform proportions of pigments and other solid ingredients.
2.	Unequal amounts of mix water.	2a.	Measure water uniformly into mixer, using only enough for a workable mix.
3.	Insufficient mixing.	3a.	Mix every batch for a minimum of 10 minutes.
4.	Admixtures added to proprietary stucco.	4a.	No admixtures (such as lime, fire clay, soap, etc.) shall be added to proprietary stucco.

Condition:
Colour Contamination

	Cause		Prevention
1.	Dirty equipment or floating water.	1a.	Clean mixer and tools when changing materials or colours.
		1b.	Keep working water clean.

Condition:
Pigment Migration

	Cause		Prevention
1.	Rain blowing against fresh colour coat.	1a.	Do not apply colour coat immediately before a rain.
		1b.	Do not apply after rain has dampened base coat. Resume when dry.
2.	Improperly installed gutters and down spouts.	2a.	Gutters and down spouts must be installed so water does not contact fresh coloured stucco.
		2b.	Diverter flashing installed at all trough and wall intersections on corresponding roof.
3.	Water-curing fresh coloured stucco improperly.	3a.	Apply a fine fog spray, but only if extreme wind or heat require curing.
		2b.	Work out of wind and in the shade whenever possible. In cooler weather it may be necessary to work on sun walls to aid in curing for colour consistency.
4.	Over spraying of cleaning water	4a.	Keep cleaning water off fresh coloured stucco. Do not clean eaves and grounds with spray nozzle at time of floating.
		4b.	When cleaning rooftops use as little water as necessary. Be sure down spouts, diverters and eaves troughs are in place.
		4c.	All cleaning of windows, vents, decking, meters, etc. should be done with a soft dry cloth, being careful not to scratch any wood, metal or plastic surfaces.

Condition:
Visible Joint & Scaffold Marks

	Cause		Prevention
1.	Cold joints in colour coat.	1a.	Apply colour coat in continuous operation over entire panel or elevation, making any necessary stops at architectural breaks.
		1b.	Any cold joint in basecoat can cause cold joint in finish coat; ie: Treat basecoat as you would a finish coat; that is finish all the wall and panels to architectural breaks.
2.	Too much floating water in joinings.	2a.	Use uniform minimum amounts of clean floating water at joinings.
3.	Scaffold improperly erected.	3a.	Set scaffold sufficient distance from wall to allow working around frames with all three coats.
4.	Scaffold remaining in place too long, causing shadow photographing of plaster, from uneven curing conditions.	4a.	Maintain normal schedule of dismantling scaffold when the work is done.

Condition:
Uneven Drying of Colour Coat.

	Cause		Prevention
1.	Difference in thickness of basecoat plaster.	1a.	In line wire construction, care in lathing is required to provide a taut, straight base so that plaster may be applied to a uniform thickness. Inward deflection of backing between framing members should be kept to a minimum.
		1b.	Framing members should be aligned so the plaster membrane will be of uniform thickness while achieving a straight true surface.
		1c.	Properly installed exterior sheathing, masonry or concrete should provide a straight base for plaster of uniform thickness.
2.	Moisture present in basecoat from improper curing of basecoat or inclement weather.	2a.	Basecoat must be cured prior to finish coat application.
		2b.	If basecoat has moisture present from rain, fog or high humidity it will cause uneven drying of colour coat. Do not proceed with application of colour coat until dry.
3.	Uneven thickness of colour coat.	3a.	Apply uniform thickness.

Condition:
Stains

	Cause		Prevention
1.	Dirt washed from roof.	1a.	Down spouts should be properly installed.
2.	Dirt splashed onto lower section.	2a.	Apply a good waterproofing agent after coloured stucco has dried.
3.	Metal rust.	3a.	Use non-corrosive flashing and screeds.
4.	Wood sap or resin.	4a.	Seal all wood adjacent to plaster areas before scratch coat is applied.
5.	Inadequate drainage.	5a.	Provide drainage for ground water so darkening of colour will not occur at base of wall.
6.	Lack of proper diverter flashings causing staining at roof and wall intersections.	6a.	Educate roofers and builders alike to spot potential problems at design phase and roofing phase.

Addenda

1.	Colour variation is most prevalent with dark, heavily pigmented colours. Lighter shades are recommended for floated finishes.
2.	Properly applied dash coat produces relatively consistent colour uniformity in all shades. Dash coats should be applied over a dry surface.
3.	All finish application on one elevation should be done with the same type float. When more than one journeyman works on an elevation, all must use the same floating technique.

Colour Correction

For whatever reason colour variation may occur, the condition usually can be corrected by fog spraying or brush coating.

Fog Spraying Mix factory-prepared brush coat with water to the viscosity of heavy cream, then dilute with water to milky consistency. Screen to remove any lumps. Pour into garden type or power sprayer. Apply over DRY surface in continuous passes until the entire wall has been covered completely.

Use as fine a spray as possible and hold the nozzle at a uniform 90� angle to the surface to insure even coverage. Spots may be "feathered out" when only a small portion of the wall shows discolouration. Allow over spray to dry, then wipe from trim with a turkish towel.

Brushing Coating: Prepare wall by spraying with water lightly and evenly 30 minutes before application. Mix material as above and pour into bucket. Apply with a brush.

Note: Curing is necessary under hot, dry, or windy conditions. When required, fog lightly the day following application.