Cladding Maintenance

Monolithic Plaster Cladding Care & Maintenance Guide

Some homes with monolithic cladding types are at risk of being leaky buildings, so you need to be especially vigilant in your maintenance checks.

The main things to look for are:

• Places where water can get into the framing, and
• Signs that water has already got in.

Water might get in through holes, cracks, loose cladding, fixings, joints that have separated, around doors and windows, anywhere where the sealing has failed, and any area where water can pool against the cladding.

Signs that water has got in include:

• Cracks and splits in the cladding or joints.
• Moisture staining or other visible water damage.
• Musty smells.
• Efflorescence (white chalky substance) at junctions or cracks.
• Mould, moss or colour degradation.
• Blistering or fading paintwork, or bubbling or peeling wallpaper.

Vulnerable areas to pay attention to:

• Check around the house to make sure the cladding is at least 175mm above the ground (lawn or garden) or 100mm from paved surfaces.
• Check pergolas, cantilevered decks, fascia or guttering penetrating the cladding, poorly formed flashings and meter boxes which are not sealed or flashed.
• Check any areas where the cladding is penetrated by bolts, screws or handrails.

For general maintenance, wash the cladding regularly. You may be required to wash at specific intervals to keep the warranty valid. Follow the manufacturer’s recommendations.

Washing the cladding will extend the life of the materials. It’s particularly important for houses near the sea.

To wash, use a soft brush and low-pressure hose, concentrating on areas rain doesn’t reach, like walls sheltered by eaves. For sea spray, moss and lichen, you might have to use specific cleaning products or a one part bleach to four parts water solution and soft brush. Hose off residue with plenty of water and avoid using ladders around wet areas as much as possible. Check with the manufacturer of your cladding and your local hardware store if you are unsure.

Before you wash, check for cracks or damage.

Don’t use a high pressure water blaster as it can damage claddings.

Monolithic Claddings

The same generic description is used to cover three quite different systems, all applied over light wooden framing:

Stucco

This is the oldest, essentially a reinforced sand/cement mix which is applied over a rigid sheathing such as thin fibre cement (commonly “Hardibacker”) or just applied over building paper. There are still plenty of “Art Deco” type houses around the country dating from seventy years ago clad like this. This style experienced a resurgence starting in the 1990’s. The plaster mix is usually around an inch or 22 – 25 mm thick. There should be continuous concrete footings around the edge supporting the outside walls, to minimise movement.

EIFS (“Chilli Bin”)

EIFS is an acronym which stands for “Exterior Insulated Finishing System” and means plastered polystyrene. This started during the rebuilding in Germany after World War II, moved to the states and finally arrived here in the eighties. The plaster is a sophisticated factory batched mix with various additives, reinforced but generally only about 3 mm thick.

Fibre-cement sheets (“Harditex”)

These are usually 2.4 x 1.2 sheets 7.5 mm thick with rebated edges which are filled with a reinforced plaster mix to create a uniform finish. Sometimes just the finish paint is added, in other cases the entire surface is plastered. “Harditex” is actually a proprietary product produced by James Hardie. When this became popular during the 1990s, a number of competing products appeared on the market.

Regardless of the specific Monolithic system in place, carry out a careful inspection of the cladding at least once a year.

For stucco check carefully for cracking of the plaster, check around flashings and other penetrations through the plaster and seek professional advice if you have any concerns.

For EIFS pay particular attention to the corners of windows and exposed edges and anywhere that the paint finish might wear or crack. Do not attempt to repair with sealant but contact an approved applicator. It may be that only certain areas require recoating. Many EIFS systems in New Zealand are specialised systems. If you are able to identify which system your home has, follow the manufacturer’s specific instructions for maintenance and repair. If you cannot establish the specific cladding system at your home, the literature on the product which it most closely resembles will give you some generic guidance on maintenance.

For texture coated fibre-cement look particularly for cracks in the jointing. Cracks in joints should be raked out and re-formed, do not attempt to seal with sealant. Contact an approved applicator to carry out repairs to the cladding. Check the waterproof coating to ensure re-painting is not required.

Look for signs that moisture might be soaking up into the cladding, often indicated by darker colouration along the bottom edges of the cladding.

Painting Care & Maintenance Guide

The effects of ultra violet light, pollution, dirt, grime and salt deposits can all accumulate and affect your painted surfaces. Manufacturers prescribe regular maintenance to preserve painted finishes. Read the warranty conditions regarding the maintenance requirements of your paint products and follow the instructions to keep your warranty valid. Some maintenance tips to consider:

Avoid cleaning any paint finish until at least four weeks after application to ensure it has had sufficient time to fully develop its properties. Cleaning of fresh paint films will damage the paint and this may require repainting to restore the desired level of finish.

Cleaning interior paintwork
Always test the cleaning method in an inconspicuous area to ensure the cleaning process you plan to use does not alter the finish of the paint. Wait until the test area has dried before using the same technique on more conspicuous areas. Walls may appear discoloured as they absorb the water, but should dry back to their original colour.

Do not vigorously scrub the surface nor use an abrasive or strong cleaning agent as you may burnish the paint surface and mar the paint finish.

Steps for cleaning interior paintwork
1. Dip a soft lint free cloth, into the paintwork cleaner solution. Do not saturate the cloth as this could lead to runs and streaking

2. Using light strokes, thoroughly wipe the area to be cleaned turning the cloth frequently to maintain a clean edge. Wipe away any excess solution. Wring the cleaning cloth out into an empty bucket before dipping it into the detergent solution again. This will minimise the appearance of streaks.

3. In order to achieve an even finish, dry the surface with one final wipe using a soft dry lint-free cloth in the direction of the paint flow. If trying to remove a localised mark, start from a radius wide of the mark and work towards it. This will minimise any ‘tide mark’ that might develop.

Be aware that walls, like windows, can accumulate a faint layer of dust or grime. A seemingly minor job of cleaning a small spot can lead to a major cleaning job. If unwillingly caught in this predicament, a feather duster can sometimes minimise the boundary between the cleaned and uncleaned areas.

Cleaning exterior paintwork
Airborne contaminants, including salt deposits, which settle on your paint film, can attack the surface and cause premature breakdown. Cleaning of exterior paintwork on an annual basis is recommended to help maintain the fresh appearance of the paintwork. Pay special attention to areas that are not subject to regular rain washing.

Moss and lichen can penetrate the surface of the paint film, damaging its integrity and reducing the useful life of the film, while mould growth can destroy the chemical entity of the resin system that holds the paint system together. The presence of moss, mould and lichen will hold moisture on the surface longer, promoting further growth of these organisms and increasing the risk of damage to the coating. Removal using the appropriate washing procedure will increase the life of the coating and maintain the aesthetic properties of the paint finish.

For an instant fresh appearance, regularly wash down the exterior with a paint prep and house wash solution diluted as recommended with water. Apply the diluted solution with a soft broom. Wash off with copious amounts of freshwater. Ensure any residue is properly washed off any windows or other glass surfaces.

For a slower-acting, longer term clean, use solutions designed for general maintenance of exterior weathered surfaces. The combination of this cleaning and natural weather conditions will slowly break down surface contamination.

Most detergents can have a negative effect on fish so avoid letting the washings run off into the storm water system.

Attend to areas of flaking paint, stained paint (treat the source of the stain, then touch-up the paint finish as required), moss and mould, and rotten areas of timber.

Moss and mould will grow through the paint surface and if left untreated will ruin the fresh appearance of the paintwork. If major moss and mould infestations appear, treat them with moss and mould killer diluted as directed with water. Wash off with copious amounts of freshwater.

Bleach is a very effective moss and mould killer, however residues can decolourise subsequently applied paint finishes, particularly when used over a porous surface. If you are repainting, ensure all bleach treated surfaces are allowed to weather and/or are thoroughly rinsed prior to repainting.

The first few months post painting
During the first few months after your paint has been applied, any of the following may occur, all of which are quite natural and do not imply inferior quality or accelerated wear:

Blocking
Thermoplastic paints (most waterborne paints fall into this category), particularly those with a high gloss, will soften under heat. Even a surface that may appear fully cured will soften and may stick to itself or other thermoplastic materials placed upon it, such as vinyl covered folders. The plasticiser in vinyl is prone to migration into touching surfaces. Where possible, avoid storing vinyl covered objects on or against painted surfaces.

Excess moisture
Excess moisture can damage your paint finish. Well-constructed modern buildings with aluminium doors and windows are almost 100% airtight. Unfortunately this has disadvantages in that any moisture generated in the building from showers, kitchens and even occupants breathing will not be able to escape unless special ventilation is provided. Rooms on southern aspects can get quite damp and often mould results. Moisture can be reduced through the installation of dehumidifiers or specially ventilated aluminium windows. Large amounts of moisture are generated during the interior decorating process. It is critical that good ventilation is maintained throughout the drying period.

The best way to achieve this is to open windows to encourage airflow and use heaters to warm the air temperature. If ventilation is poor, the paint finish may not fully cure. Excess moisture can lead to surfactant leaching, blistering and mould problems. While dampening a porous surface can ease paint application in exterior situations, paint will never cure over a permanently wet surface and blistering may result, particularly on horizontal surfaces where water is liable to pond.

Fading
In common with all exterior surface coatings, the colour of your paint finish may be affected by U.V. light. Even the finest pigments commercially available are liable to change after constant exposure to sunlight. Any changes will be gradual, but after a few years the difference between shaded and exposed areas may become noticeable. The extent of fading is often only seen when part of a wall area requires touch up with the original colour.

The combined presence of strong U.V. light and lime in the surface can lead to premature fading. Sometimes lime staining is mistaken for fading. Lime staining occurs when the lime in the surface has leached through and is deposited on top of the paint surface as a white deposit that looks similar to fading. If this occurs, the lime must be blocked off with a suitable paint system. It is recommended that all fresh plaster surfaces are coated with lime-lock first.

A UV Protective Glaze may be used as a finish coat over freshly painted bright organic hues and shades to protect these more vulnerable pigments against fading.

Pigment transfer
Bright interior colours, such as reds in particular, can be vulnerable to pigment transfer, where a tiny amount of the pigment can be removed when wiped with a cloth. Pigment transfer does not affect the appearance of the paint finish, nor its durability, however it can cause marking on other items that come into contact with the paint finish, such as sofas and curtains. Simply wipe the surface area evenly to remove the loose pigment. Alternatively, a glaze coat can be applied.

Surfactant leaching
Waterborne interior products in particular are vulnerable to surfactant leaching, where some areas of the paint surface appear to be covered in white streaks, giving a watermark effect. Surfactant leaching only affects the appearance of the paint finish, not its durability. It cannot be accurately predicted or prevented, but is more likely to occur in wet areas, such as bathrooms, where ventilation is poor. Surfactant leaching is caused by water sitting on freshly applied waterborne paints. Water softens the fresh paint and draws out water soluble surfactants. As water dries off these are deposited on the surface. These deposits are easily removed early on by simply cleaning the surface following the interior paintwork instructions earlier in this brochure. The problem may occur once or twice again before all leachable material is completely removed. If left, the deposits may etch the surface and leave a permanent mark. This should diminish over a few months and is only of cosmetic concern.

Surfactant leaching is usually associated with marginal painting conditions. Paint colours that require higher levels of tinters are more prone to surfactant leaching than are white paints because of the ingredients that are present in tinters. To prevent surfactant leaching, it is best to avoid application in the late afternoon if cool, damp conditions are expected in the evening or overnight. Ensure adequate ventilation is maintained during the drying period. If surfactant leaching does occur, carefully clean the surface as soon as possible.

Recommended maintenance schedule for steelwork
Washing and cleaning
Washing schedule will vary according to micro environment. Irrespective of system life all areas sheltered from rain washing should be washed down with freshwater on a quarterly basis and on yearly cycle all painted surfaces should be washed with paint prep and house wash followed by rinsing with freshwater. This will remove salt, dirt, and contaminate build up on painted areas.

Roofing and Roofing Membrane Care & Maintenance Guide

1. General Care and Maintenance.

Your roof needs regular attention to give you years of long service. It is a requirement of the manufacturers’ warranty that this regular maintenance is carried out. Read the warranty conditions regarding the maintenance requirements for your roof products and follow the instructions to keep your warranty valid.

The following are some basic requirements that will prolong the life of your roof:

a) Provide proper drainage. Keep the roof surface clean of leaves, twigs, paper or accumulated dirt at drain areas to avoid clogged drains. Excessive ponding of water on the surface of the membrane will increase the probability of moisture entering the structure in the event of a puncture or cut in the membrane.

b) Avoid degrading the membrane. Be careful that products you use on the roof or cladding above it, are not harmful to the roofing materials. For example, an oil based paint or stain will seriously damage butyl roofing, and corrosive cleaning chemicals will damage the base of steel roofing. Do not expose the membrane to the following, due to possible degradation of the membrane.

1) Liquids containing petroleum products.

2) Solvents.

3) Grease or oils used for air conditioning or compressor units.

4) Kitchen fats or other animal fats.

5) Chemicals.

Catch pans and proper drainage of these pans or other means of protection may be used for membrane protection. Prolonged exposure to these materials will cause swelling and possible degradation of the membrane if spills are not removed.

c) Foot traffic. On roof areas with 1.0 mm or 1.2 mm membrane, the membrane should be protected from continual foot traffic. This can be achieved by using walkway pads or rolls. Wear soft rubber soled shoes to protect yourself and also the roof.

d) Exercise care with tools and equipment. To avoid puncturing the membrane when it is necessary for workers to be on the roof to service rooftop equipment. When servicing units, care should be taken when placing doors, lids or sharp objects on the membrane surface. When moving units or equipment on roofs, avoid overloading and membrane damage by installing smooth plywood over the membrane prior to moving the equipment.

e) Remove all debris, such as glass, bolts, nails, screws, metal shavings, etc. and any other material that may promote punctures or cuts to the membrane.

2. Period Inspections

A periodic inspection program should be established by the building owner. Roof inspections should be conducted by qualified personnel, beginning when the roof is completed and continuing at least twice a year thereafter, preferably in the spring and autumn. High roofs require scaffolding or safety equipment before maintenance is attempted.

The inspection should concentrate on “high risk” areas such as hatches, drains and around all roof top equipment, as well as a general inspection of the entire roof. With long run roofing such as corrugate or rib roofing, a periodic check should be made on nail fasteners to ensure that the odd one has not lifted. Do not over drive the nail as that is as likely to cause problems as a loose fastener.

Inspections should also include the examination of the roof deck if possible from the underside for evidence of leaks, deteriorated decking, structural cracks, or movement and other deficiencies. Parapets and edging should also be examined for evidence of cracking, deterioration and moisture infiltration.

In addition to the scheduled semi-annual inspections, roof inspections should also be conducted whenever any of the following conditions occur:

a) Exposure of the roof to severe weather conditions, such as strong winds, hail or long continued heavy rain. (Examine the roof for severely ponded conditions, broken payers, displaced payers or gravel, debris, and any other damage to the building components that may allow moisture to infiltrate. The membrane should be examined in areas where damage has been identified for punctures, tears or loose fasteners.)

b) After repair or replacement of roof top equipment, and at any other time when the roof may become exposed to the activities of other trades where damages may occur. Never allow people inexperienced in working on roofing, to walk on your roof. The damage from this source is very common. It is unsightly and may affect the weathering abilities of the roof.

c) Paint on roofing membranes should be recoated every 6-8 years.