6 minute read · Exterior painting
Exterior painting preparation should establish that the surface is sound, clean, dry enough for the selected system and suitable to repaint. It includes checking the old coating, removing interfering material by an appropriate method, dealing with local defects and identifying repairs that must happen first. It is not one fixed pressure-washing and primer recipe.
For a house in Dundalk or a nearby area, describe the actual walls, timber and visible defects when discussing exterior painting. Good preparation starts with those differences. A wall that looks dirty in a photograph may also have loose coating or a moisture problem that needs checking in person.
Survey the substrate and existing coating
Map the exterior into surfaces: render, pebbledash, painted brick, concrete details, timber and any other materials. Record previous products if known. A generic masonry coating is not permission to paint every brick, stone or modern render system. Factory-finished surfaces and specialist renders may need advice from their supplier.
Then record the condition by location. Look for flaking, powdery residue, cracks, biological growth, staining below gutters and deterioration near ground level. Distinguish what is visible from what is established. A photograph can show a stain pattern but cannot identify the moisture source or measure the adhesion of every old layer.
| Survey finding | Preparation question | Possible dependency |
|---|---|---|
| Sound dirty paint | What cleaning method suits the surface and system? | Allow adequate drying afterwards |
| Loose coating | How far does failure extend into apparently sound areas? | Wider preparation may be needed |
| Persistent powdering | Does residue remain after suitable cleaning? | A specified stabilising treatment may be considered |
| Cracks or hollow render | Is this a decorative defect or a repair issue? | Appropriate building assessment |
| Growth or damp staining | What is causing and sustaining it? | Moisture or exposure may need attention first |
If the coating or material is unknown and potentially hazardous, assess it before disturbance. Do not use a general DIY preparation article as authority for stripping an older surface.
Cleaning and loose material
Choose cleaning for the substrate, the contamination and the condition. High pressure is not automatically appropriate for friable render, joints or vulnerable details. The objective is to remove what interferes with the coating while avoiding damage and managing the resulting water and debris.
The Dulux Trade Weathershield Smooth Masonry sheet describes washing previously painted surfaces and dealing with poorly adhering coatings before repainting. It also requires clean, sound, dry conditions. Its instructions belong to that system, rather than a universal prescription for every wall.
Loose paint cannot be made sound by coating over it. Establish a firm retained edge and the extent of adhesion failure using an appropriate assessed method. Where layers detach beyond the visible patch, the necessary preparation may be larger than the first photograph suggested. The flaking paint diagnosis guide helps separate that assessment from the repaint sequence.
Powdering and porosity are different from general dirt. Do not apply stabilising solution to every surface as an insurance coat. Confirm whether the chosen system calls for it on the actual remaining condition. Too much emphasis on a product name can distract from the more important question of whether the substrate itself is sound.
Defects and repair responsibilities
Small decorative imperfections and building defects should not be bundled together without explanation. A hairline mark, an open joint, a moving crack and a hollow area of render may require different expertise. Painting over them does not determine whether they are stable or suitable to retain.
Check obvious water-management details from a safe position: staining below a gutter, failed coping or repeated damp near a sill. These observations help describe the issue, but they are not a diagnosis. If a leak or damp source is suspected, arrange the relevant assessment and repair before agreeing that the wall is ready.
A hypothetical rear wall has two conditions. Most of the coating is sound but dirty; a patch below a damaged downpipe keeps peeling. The sound area may be ready for routine preparation. The recurring patch should wait for the water issue to be resolved and the substrate assessed. Washing and painting everything on the same day would ignore the dependency.
Write down who handles each repair, what material is used and how readiness for coating will be established. New mortar, filler or render has its own drying and curing requirements. Do not copy a standard waiting period from an unrelated product or assume that a dry-looking surface has finished releasing moisture.
- Decorative preparation included in the painting scope.
- Repairs assigned to another trade or awaiting assessment.
- Readiness checks after those repairs.
- Unknown conditions that could change the scope.
- Protection of windows, paths, gardens and neighbouring surfaces.
- Access arrangements for the actual working areas.
Specify a suitable coating system
Choose the finish only after the substrate and condition are understood. Compare the approved surfaces, retained coating compatibility, preparation instructions and any primer requirements. The masonry paint selection guide shows how to read those parts of a current technical sheet.
For example, the Dulux Trade professional products guide limits its Weathershield Stabilising Primer to dry masonry that remains powdery or friable after thorough preparation and says not to seal sound new or bare surfaces. That discriminating instruction is more useful than a blanket "prime everything" rule. Check the current local sheet before specifying the product.
Agree the application tools, coat build and product-specific weather limits. A shower-resistant claim for a topcoat does not mean wet masonry is ready to paint, and a primer may have a different weather window from the finish. Allow for all stages rather than only the final coat.
Before the work starts, the useful output is a surface-by-surface preparation description. It should explain what stays, what is removed, what is repaired and what is still uncertain. That makes both the quotation and the finished work easier to assess without pretending that every hidden layer can be judged from photographs.
Practical questions
Does every exterior wall need pressure washing?
No universal method suits every substrate and condition. Vulnerable render, joints and old coating can be damaged by unsuitable pressure or water entry. Establish the cleaning objective and the surface limitations first, then allow the required readiness before coating. Cleaning should prepare the wall rather than create a new defect.
Is stabilising solution always a good extra coat?
No. It has a defined role within particular systems and surface conditions. Applying it by habit can ignore the distinction between sound masonry and residual powdering after preparation. Use the selected manufacturer's actual instruction for the assessed wall instead of treating a sealer as general insurance.
Can minor cracks simply be painted over?
First distinguish a stable decorative imperfection from an open, moving or recurring defect. Paint does not establish the cause or stability of a crack. The repair material and coating need to suit the actual condition, with appropriate assessment where the defect may extend beyond decoration.
Exterior painting: discuss your surfaces and scope. Contact the team with your area and photographs.