Blistering of sandwich panels
Blistering / bending is caused by thermal forces that occur in a sandwich panel as the result of a so-called thermoshock. This causes the outer skin to become detached from the PUR- PIR / EPS/ mineral wool insulation resulting in hollow spaces being created behind the outer sheet. After heating up, this space will expand and form a blister, swelling or bend.
Blistering in panels
Blistering in panels is evident when:
- Thermoshock occurs, this can be on building site but also during production.
- Forced tension, bending, hollowing during assembly, uneven surface, after heating up the stresses possibly cause imperfections.
- Darker colours of panels increase the temperature of the outer sheet, this can cause more tension.
- A thin steel thickness of outer sheet can cause more imperfections and the chance of blistering is much higher, cheaper isn't always better.
- Detached foam to outersheet during production.
- Less profile in the outer sheet ( flat panels) gives less strength.
- Problems of cooling down the panel during production.
Test set-up, panels are heated
Deflection due to heating / Thermoshock simulated
Detached outer skin, location where detachment occurs is visible / Folding
Inside of panel after folding / Detachment is visible on inside of outer skin
Where does this occur?
In many cases, blistering or folding occurs on the facade, and on the section of a building that receives the most sun-hours (south facade).
What is the risk?
Due to warming up, the blister will become increasingly bigger and thus also become more detached, so that the panel will have to be replaced.
Can it be repaired?
Depending on the size and cause, most blisters can be repaired. We have developed 2 techniques for this:
- Vacuum bonding technique
- Comprehensive damage repair by fixing, filling, spraying
1. Vacuum binding technique
2. Repairing damaged facades
Van Heemskerk Damage Repair
Van Heemskerk has the expertise and the experience to detect blistering (already at an early stage) and to professionally treat it using the correct materials and techniques.
We repair around the globe in many country's, distance is not a problem. We can provide a quick advice and solution.