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Interior paint problem solver

Even the most professional painters can run into problems. But the good news is that there are solutions for almost all of them. For each problem you’ll find a guide to identifying it, its causes, solutions and in some cases, how to prevent the problem from happening altogether.

  • Interior – Blocking

    Blocking is the undesirable sticking together of two painted surfaces when pressed together (e.g., a door sticking to the jamb).

    It happens when a sufficient drying time has not been allowed before closing doors or windows and is more common when using low-quality semi-gloss or gloss paints.

    How to fix it:
    Use a premium semi-gloss or gloss acrylic enamel paint like Dulux Aquanamel. Low quality semi gloss and gloss water-based paints can have poor block resistance, especially in warm, damp conditions. Always follow paint label instructions and dry times. Acrylic enamel paints have a better early block resistance than vinyl latex paints, or solvent-based enamel paints. Finally, a light sprinkle of talcum powder over tacky areas of paint relieve persistent blocking.

  • Interior – Burnishing

    The gloss of a paint can wear down when subjected to rubbing, scrubbing or having an object brush up against it.

    Burnishing commonly occurs where a flat paint is used in highly trafficked areas rather than a paint with a higher level of sheen. Frequent washing and spot cleaning can also exacerbate burnishing, especially on lower quality paints with poor stain resistance and poor scrub resistance.

    How to fix it:
    Paint heavy wear areas such as doors, window sills and trim with a premium semi gloss or gloss acrylic enamel like Dulux Wash&Wear. This type of paint offers both durability and easier cleaning capability. In high traffic areas, choose a low sheen, semi-gloss or gloss rather than a flat sheen level. Clean painted surfaces with a soft damp cloth or sponge and non-abrasive cleansers; rinse with clean water.

  • Interior – Cracking, Flaking or Peeling

    Cracking, flaking or peeling is the splitting of a dry paint film. This is a problem that needs fixing as it can lead to complete failure of the paint. Initially, the problem appears as a hairline crack, before evolving to flaking of paint chips.

    Cracking and flaking is caused by:

    • Use of a lower quality paint that has inadequate adhesion and flexibility.
    • Over thinning the paint or spreading it too thin.
    • Poor surface preparation especially not applying a primer before painting.
    • Poor adhesion of the underlying coats.
    • Excessive hardening and embrittlement of alkyd paint as the paint job ages.

    How to fix it:
    If caught early, it may be possible to correct superficial cracking by simply removing the loose or flaking paint with a scraper or wire brush, sanding to feather the edges, then priming any bare spots and repainting.
    However, if the cracking goes down to the substrate, you’ll have to remove all of the paint by scraping, sanding and/or using a heat gun. You can then prime and repaint the surface with quality products like Dulux One Step Acrylic Primer Sealer Undercoat and Dulux Wash&Wear.

  • Interior – Foaming or Cratering

    Foaming or cratering is the formation of bubbles (foaming) and resulting small, round concave depressions (cratering) in a paint film, during paint application and drying.

    Several things can cause foaming or cratering:

    • Shaking a partially filled can of paint.
    • Use of low quality paint or very old latex paint.
    • Applying (especially rolling) paint too rapidly.
    • Use of a roller cover with wrong nap length.
    • Excessive rolling or brushing of the paint.
    • Applying a gloss or semi-gloss paint with a long nap roller.

    How to fix it:
    All paints will foam to some degree during application; however, higher quality paints are formulated so the bubbles break while the paint is still wet, allowing for good flow and appearance. Avoid excessive rolling or brushing of the paint or using paint that is more than a year old. Always apply gloss and semi-gloss paints with a short nap roller.

  • Interior – Lapping

    Have you noticed that there are areas of denser colour or higher gloss where wet and dry layers overlap during painting?

    This is caused by not maintaining a ‘wet edge’ while painting.

    How to fix it:
    To maintain a wet edge, apply your paint towards the unpainted area and then back into the just-painted surface. Brushing from "wet to dry," rather than the other way around will help produce a smooth, uniform appearance. It’s also wise to minimise the area being painted and plan for interruptions at a natural break, such as a window, door or corner. Using a top quality water-based paint makes it easier to avoid lapping problems because higher solids (pigments and binder) content makes lapped areas less noticeable. If substrate is very porous, it may need a primer/sealer to prevent paint from drying too quickly, reducing wet edge time and therefore making lapped areas noticeable. Solvent-based paints generally have superior wet edge properties, and therefore less lapping.

  • Interior – Mould

    If you’ve noticed black, grey or brown areas on your painted surface, chances are you’re dealing with a mould problem.

    As with mould anywhere, interior mould is caused by moisture. It’s often found on areas that are damp, and receive little natural light and are poorly ventilated (bathrooms, kitchens and laundries). Mould is more likely to occur after use of a lower quality paint, failure to prime bare wood before painting, or if you’ve painted over a coating of mould without removing it.

    How to fix it:
    First, test for mould by applying a few drops of household bleach to the discoloured area.If it disappears, it is probably mildew. Remove it by scrubbing with a diluted household bleach solution (one part bleach, three parts water). Be sure to wear rubber gloves and eye protection. Power washing is also an option. Then, rinse thoroughly, prime any bare timber and apply one or two coats of a top quality paint like Dulux Wash&Wear Kitchen and Bathroom. If possible, install an exhaust fan to help prevent re-growth.

  • Interior – Mud Cracking

    Deep, irregular cracks resembling dried mud in your paintwork is called mud cracking.

    Mud cracking can occur when:

    • Paint is applied too thickly, usually over a porous surface.
    • Paint is applied too thickly, to improve inherent poor hiding (coverage) of a lower quality paint.
    • Paint is allowed to build up in corners upon application.

    How to fix it:
    Remove the cracked paintwork by scraping and sanding. Prime and repaint the surface with a premium water-based paint like Dulux Wash&Wear and a roller with appropriate nap length. Sanding the surface smooth before repainting with a premium water-based paint can also repair mud-cracked areas. Premium quality paints have a higher solids content, which reduces the tendency to mud crack. They also have very good application and hiding properties, which minimises the tendency to apply the paint too thickly.

  • Interior – Picture Framing

    Picture Framing occurs when a wall is painted with a roller, but is brushed at the edges and corners. The brushed areas generally appear darker, resembling the 'frame' of a 'picture.' Also, sprayed areas may be darker than neighbouring sections that are brushed or rolled.

    Picture framing from brushing usually occurs because brushes result in a lower spread rate than rollers, which produces a thicker layer of paint. It can also occur if colourant is added to non-tintable paint, or if the wrong type or level of colourant is used.

    How to fix it:
    Work in smaller sections of the room to maintain a 'wet edge' and ensure spread rates between brushes and rollers and similar. With tinted paints, be sure the correct colourant-base combinations are used. Factory colours, as well as in-store tints, should be thoroughly shaken at time of sale, and the paint should be stirred well prior to use.

  • Interior – Roller Marks / Stipple

    Roller marks or stipple is the unintentional textured pattern that’s left in the paint by the roller.

    This can occur when:

    • The incorrect roller cover is used.
    • Lower quality paints and/or rollers are used.
    • The incorrect rolling technique is applied.

    How to fix it:
    Use the proper roller cover and avoid too long a nap for the paint and the substrate. Use quality rollers to ensure adequate film thickness and uniformity. High quality paints also tend to roll on more evenly due to their higher solids content and levelling properties. Another great tip is to use water to pre-dampen roller covers to be used with water-based paint. Be sure to shake out excess water before painting and don't let paint build up at roller ends. Begin rolling at a corner near the ceiling and work down the wall in three-foot square sections. Spread the paint in a zigzag 'M' or 'W' pattern, beginning with an upward stroke to minimise paint spatter. Then, without lifting the roller from the surface, fill in the zigzag pattern with even, parallel strokes.

  • Interior – Poor flow and leveling

    Poor flow and levelling is when paint fails to dry with a smooth film, resulting in unsightly brush and roller marks after the paint dries.

    Causes of poor floor and levelling include:

    • Using an inferior quality paint.
    • Applying additional paint to 'touch up' partially dried painted areas.
    • Re-brushing or re-rolling partially dried painted areas.
    • Use of the wrong type of roller cover or a poor quality brush.

    How to fix it:
    Use a premium quality water-based paint. These are generally formulated with ingredients that enhance paint flow and lead to a smooth film. When using a roller be sure to use a cover with the recommended nap length for the type of paint being used. Use of a high quality brush is also important; a poor brush can result in bad paint flow and leveling.

  • Interior – Poor Hiding

    Poor hiding is exactly what it sounds like. It’s the failure of your dried paintwork to obscure or 'hide' the surface to which it is applied.

    Before you reach for the roller again, your problem isn’t the amount of paint. It’s more likely to be one of the following:

    • Use of a low quality paint.
    • Use of low quality tools or the wrong roller cover.
    • An improper combination of tinting base and tinting colour.
    • Poor flow and leveling (see Poor Flow and Leveling).
    • Use of a paint that is much lighter in colour than the substrate, or that primarily contains low-hiding organic pigments.
    • Application of paint at a higher spread rate than recommended.

    How to fix it:
    If your substrate is significantly darker than your chosen paint colour, or features a pattern, it should be primed before applying the top coat. Always use a premium quality paint for better hiding and flow. Tools are also important. Always use quality tools and the recommended roller nap, if using a roller. Follow manufacturer's recommendation on spread rate and if using tinted paint, be sure to use the correct tinting base.

    If you must use a low-hiding organic colour, always apply a primer first. We recommend Dulux One Step Acrylic Primer Sealer Undercoat.

  • Interior – Poor Scrub Resistance

    Poor scrub resistance can be identified when paint film wears away when scrubbed with a brush, sponge or cloth.

    It can be caused by any of the following things:

    • Choosing the wrong sheen for the area.
    • Use of a lower quality paint.
    • Use of an overly aggressive scrub medium (see also Burnishing).
    • Inadequate dry time allowed after application of the paint before washing it.

    How to fix it:
    Areas that need require frequent cleaning should be painted with a highly washable premium quality paint that’s specially formulated to provide scrub resistance. High traffic areas may require a low sheen, semi-gloss or gloss paint rather than a flat paint – the additional gloss is less porous and provides improved scrub resistance.

    Once you’ve completed your paintwork, always allow an adequate dry time, as scrub resistance does not fully develop until the paint is thoroughly cured. Typically, this is one week. Try washing the painted surface with the least abrasive material and mildest detergent first. For optimum scrub resistance, we recommend using Dulux Wash&Wear.

  • Interior – Poor Sheen Uniformity

    Also known as ‘flashing’, poor sheen uniformity can be identified as shiny or dull spots on a painted surface that lead to an uneven gloss.

    Possible causes of flashing:

    • Uneven spread rate whilst painting
    • Failing to properly prime a porous surface
    • Poor paint application that results in lapping (see Lapping).

    How to fix it:
    New substrates should always be primed and sealed before applying the top coat to ensure a uniformly porous surface. Without the use of a primer or sealer, it’s likely you’ll need an extra coat of paint to do the job. Make sure you always apply paint from 'wet to dry' to prevent lapping. Often, applying an additional coat will even out any sheen irregularities.

  • Interior – Poor Stain Resistance

    Poor stain resistance is the failure of paint to resist the absorption of dirt and stains.

    This can be caused by the use of a low quality paint or the application of paint to an unprimed surface.

    How to fix it:
    Always choose a high quality water-based paint. They contain binders that have been specially formulated to prevent stains from penetrating the painted surface, meaning it’s easy to clean up any spills or accidents.

    Priming new surfaces also reduces the porosity of a surface, ensuring maximum film thickness in the top coat and maximum stain resistance. We recommend using Dulux One Step Acrylic Primer Sealer Undercoat and Dulux Wash&Wear.

  • Interior – Roller Spattering

    Roller spattering is the tendency of a roller to throw off small droplets of paint during application.

    Generally it’s caused by incorrect roller technique and applying the paint to rapidly. However, using a low quality paint and/or roller and incorrect roller covers can also cause spattering.

    How to fix it:
    Always choose a high quality paint. They are formulated to minimise spattering. The right paint should be complemented with the right roller too – choose a high quality roller, with the appropriate nap length. When painting, be careful not to overload the roller with paint as this will result in excess spatter. Working in three-feet square sections, apply the paint in a zigzag 'M' or 'W' pattern, and then fill in the pattern – this will also reduce the likelihood of spattering, giving you smooth, consistent paintwork.

  • Interior – Sagging

    Sagging is the downward "drooping" movement of the paint film immediately after application that results in an uneven coating.

    It’s not a great look, and can be cause by several things:

    • Application of a heavy coat of paint
    • Painting in excessively humid and/or cool conditions.
    • Application of over-thinned paint.
    • Airless spraying with the gun too close to the surface being painted.

    How to fix it:
    If the paint is still wet, immediately brush out or re-roll it to redistribute the excess evenly. If your paint has already dried, sand and reapply a new coat of top quality paint. Take a moment to correct any unfavourable conditions too; do not thin the paint; avoid cool or humid conditions and sand glossy surfaces.

    Always apply paint at its recommended spread rate and avoid piling it in. Two coats of paint at the recommended spread rate is better than one heavy coat, which can also lead to sagging. In this instance, gravity is not your friend, so consider removing doors to paint them while supported horizontally.

  • Interior – Wrinkling

    Just like our skin, wrinkling in paintwork can be identified by a rough, crinkled paint surface, which occurs when uncured paint forms a 'skin'.

    It can be caused by any of the following:

    • Applying paint too thickly (this is more likely when using alkyd or oil-based paints).
    • Painting during extremely hot weather or cool damp weather, which causes the paint film to dry faster on top than underneath.
    • Exposing uncured paint to high humidity levels.
    • Applying a top coat of paint to insufficiently cured primer.
    • Painting over a surface contaminated with dirt, dust or wax.

    How to fix it:
    First, scrape or sand the substrate to remove wrinkled coating. If using a primer, allow it to dry completely before applying top coat. Then, repaint your surface in ideal conditions, applying an even coat of top quality interior paint.

  • Interior – Yellowing

    Yellowing is the development of a yellow cast in aging solvent-based enamels. It’s most noticeable in the dried films of white paints or clear varnishes.

    Yellowing can be caused by the oxidation of alkyd or oil-based paint or varnish, heat from household items like stoves and heaters, or a lack of light to the area.

    How to fix it:
    Where possible, choose a top quality water-based paint and/or a non-yellowing varnish. They do not tend to yellow as much as solvent-based paints, and are the only sure fire way to protect against yellowing. We recommend Dulux Aquanamel.

  • Interior – When droplets appear on acrylic paint

    Have you noticed small droplets appearing on your fresh coat of acrylic paint? Don't panic – it’s a normal part of the process.

    Sometimes, when acrylic paints are drying small, light coloured droplets will appear on the surface. This usually happens if newly painted surfaces are exposed to moisture, either by dew, high humidity or other types of moisture such as steam.

    These droplets cause no downgrading of the paint film's durability. They only affect the appearance. Once the paint is dry, wash the surface with sugar soap, and then rinse with plenty of water. Sometimes droplets may continue to appear for some time and will need wiping down until they stop. These droplets are simply surfactants, which are drawn to the surface by moisture.