Why does exterior paint peel on Algarve homes?

Start with the pattern, not the paint tin

Failure at the base of a wall may point towards splashback, drainage or moisture moving through the substrate. Local damage below a gutter or parapet deserves a different investigation from uniform fading on a sun-exposed elevation.

Photograph the full wall and the detail. Note whether the surface is powdery, blistered, cracked, stained or simply faded. Several symptoms can occur together, so a photograph cannot replace an on-site check when the cause remains unclear.

Find water and weak material before repainting

A new finish depends on what remains underneath. Loose paint, friable render, open cracks and damp areas can prevent a sound bond. Moisture can arrive through leaks, failed joints, condensation, rising damp or poor drainage, and each route needs a different response.

Painting a visibly wet or biologically contaminated surface is not a repair. The source should be addressed, the wall allowed to dry and the failed material removed before a coating system is selected.

• Check gutters, downpipes, parapets and the base of the wall
• Compare the same area after dry weather and after rain
• Mark cracks that reopen or continue through the render
• Separate structural or moisture investigation from cosmetic painting

Preparation must match the surface

Chalk, salts, algae, dirt and old loose coating all change adhesion. Cleaning pressure and products should be chosen for the render and existing finish, followed by the drying and repair time required by the chosen materials.

A small test area helps reveal whether the surface remains weak after cleaning. Primer and finish coats should form one compatible system, applied within the limits stated in their technical sheets.

Choose the work window after the scope is clear

Algarve weather averages are useful for planning, but the wall and short-range forecast decide the start date. Avoid rain, strong wind and overheated sun-facing surfaces, and leave enough time between cleaning, repairs, primer and finish.

The most reliable estimate therefore identifies the cause to be investigated, the preparation standard, access and measurable areas — not only the number of paint coats.