Scheduled visit
Blistering on an external wall in summer
Bubbles form in the paint on an outside wall, usually in the hottest months. Pressing them may release a little water or powder. Heat is turning moisture trapped in the wall into vapour that pushes the paint off.
Painting & Finishes
Scheduled work, planned around your availability and the weather.
Call nowRequest a painting survey on WhatsApp01LIKELY CAUSES
What usually sits behind this symptom, and what tells one cause from another.
Moisture in the wall from cracks or failed details
Moisture readings high behind the blisters; cracks or failed seals nearby.
Non-breathable paint over a damp substrate
Existing coating is impermeable; blisters contain water.
Paint applied over damp render or in full sun
Blistering across a whole recently painted area.
02BEFORE ANYONE VISITS
What you can safely check.
- Note whether blisters contain water or are dry.
- Check the area for cracks or gaps around windows and fixings.
- Notice whether it is the same wall every summer.
- Do not pick blisters open if the wall is wet.
03WHAT WE MEASURE
We take moisture readings, check for cracks and failed sealant nearby, and identify the existing paint system. Repainting waits until the wall is dry and the moisture route is closed.
04IN A VILLA
Villa walls face strong sun, and paint on a south or west face can reach very high surface temperatures. Any moisture trapped behind a non-breathable coating expands and lifts the paint.
05THE FIX
Which repair, and when.
Blisters break, letting more water into the wall, and the area spreads every summer.
Close moisture routes, dry out, then repaint
Water is entering through cracks or details.
Strip and use a breathable system
An impermeable coating is trapping moisture.
Repaint in suitable conditions
Previous paint went on in the wrong conditions.
06Typical villa painting work
Quoted after survey — area and preparation dependent
Preparation is the variable, not the paint. A villa needing crack repair and moisture remediation costs substantially more than one needing coats alone, and we would rather show you why on site than give a number that changes later.
07QUESTIONS
- Can blisters be sanded and repainted?
- Only once the moisture source is fixed and the wall is dry, or they return.
- Why only in summer?
- Heat turns trapped moisture into vapour, which pushes the paint off.