Solving your paint problems

Before painting a damaged or problem surface, careful preparation is essential.

Decorating a period house or older property inevitably involves tackling a multitude of problem surfaces - often caused by paint failures created under a range of conditions from damp, mouldy environments through to smoke damage and poor ventilation.

Let's take a look at some of these paint failures, the type of problem surfaces they create and the solutions currently available:

This can occur on damp wood and plaster if solvent based paints such as gloss or eggshell have been over-coated with a conventional emulsion paint in an area suffering from high levels of condensation - such as damp kitchens or bathrooms. The presence of moisture is frequently the cause.

SOLUTION Scrape back the paint to a firm edge and lightly abrade the surface. Apply one coat of primer sealer and follow with one or two finishing coats - ideally microporous.


Caused by crystallisation of salts found in bricks or plaster. Soluble salts are brought to the surface by moisture which appear either as patches of crystal or as a hard shiny film. Paint should not be applied until the efflorescence has ceased to appear and has been removed.

SOLUTION Remove efflorescence deposits with a course Hessian sacking. Hard shiny efflorescence should be sanded to roughen the surface prior to painting. On new extensions it is advisable not to use conventional solvent based paints such as gloss or eggshell for at least 12 months - allowing the surface to dry out thoroughly.

This is typical problem with older properties painted with distemper or whitewash.

SOLUTION Completely remove surface coatings by washing with warm water and detergent solutions. Rinse with clean water, taking care to change the rinsing water regularly. If after thorough preparation, the surface is still slightly powdery it may be necessary to seal it with an appropriate primer or plaster sealer prior to finishing.

Can stain paint coatings and is most likely in conditions of high humidity and poor ventilation.

SOLUTION Treat affected areas with a fungicidal wash. Leave for 24 hours and then wash down to remove residues and allow to dry thoroughly. In severe cases a second treatment may be required. Installing additional ventilation or increasing room temperature can improve conditions within the room affected.

Brown stains may be the cause of past water leaks or burst pipes. Staining can also be caused by heavy deposits from tobacco tar from cigarette smoke. Both tend to be worse on water-based emulsion paints than on conventional oil-based finishes such as gloss.

SOLUTION Ensure the source of damp is repaired, and the surface is thoroughly dry. Spot prime the affected area with an alkali-resisting primer before painting. If repainting with water-based paints it is advisable to allow a few days for the oily residues of the primer to disappear, otherwise paint may not adhere to the surface - wash the surface with detergent solution, rinse with clean water and allow to dry thoroughly. Repainting can be more successful using water-based coatings in low-light areas.


This is usually caused by moisture beneath the paint film. With conventional emulsion paints, peeling can also occur if applied over dirt, oil, grease or a previously gloss-painted surface.

SOLUTION Scrape back to a firm edge and lightly abrade the surface. Apply one coat of primer sealer and follow with one or two finishing coats.


Classidur a unique interior renovation paint....

From scraping off and washing down through to sealing and undercoating, preparation will take the lion's share of the budget when dealing with the treatment and redecoration of problem surfaces. To keep costs down, an alternative option is to use technically superior renovation paint, such as Classidur, available from Ptarmigan. Requiring minimal preparation, Classidur paint can simply be applied directly over most of the above problem surfaces as well as those caused by nicotine, soot, water, fire damage, exhaust fumes and smoke deposits with no washing down or specific preparation.

Developed in Switzerland, Classidur paint features "zero tension". Unlike a conventional emulsion, when this paint dries it exerts no stress on the surface. This means it will not flake or peel off - even on the most difficult surfaces, such as limewash or distemper. And, like limewash and distemper, Classidur paint features a high level of vapour permeability - 88%, compared to 45% - 50% for conventional emulsions - allowing surfaces to breathe and dry out after redecoration greatly reducing the risk of paint blistering or peeling.

Should you wish to discuss how the paint can be used in practice or require further technical advice or assistance please contact Ptarmigan Technology Limited on:

Phone:   +353 (0)49 433 9490