How to successfully bond insulation materials:
It all comes down to the finish
What is this about?
When it comes to XPS and EPS insulation materials, the success of the bonding process depends on more than just the adhesive. Often, the application process, wetting, and adherence to the open time are critical factors.
When it comes to insulation materials, proper installation is often more critical to success than the adhesive itself.
Typical applications
- Insulation boards on wooden substrates (Collano BM 810, Collano A 1970)
- Insulation boards on concrete substrates (Collano BM 833, Collano BM 866)
- Interior finishing (Collano BM 810, Collano BM 833, Collano BM 866)
- Wood-frame and prefabricated construction (Collano BM 810, Collano A 1970)
- Window connections and window sill designs (Collano BM 833, Collano BM 866)
- Floor and flat roof structures (Collano BM 833, Collano BM 866)
- Sandwich and composite elements (Collano BM 810, Collano A 1970)
Best practice: Check the materials to be joined in advance.
What is the challenge?
XPS and EPS are made of polystyrene. Adhesion is often achieved through:
- Wetting
- Mechanical anchoring
- Proper installation
and less about a strong chemical bond.
Common mistakes in practice
- Open time exceeded
- Insufficient bond pressure
- Adhesive applied to the wrong surface
- Direct sunlight
- Wind and dry air are often underestimated
Real-world example
In the summer, wind and heat can significantly shorten the open time of 10 minutes on a construction site.
Here's how to do it
1. Apply adhesive to the insulation
Apply to the critical material.
2. Work in the adhesive
Press lightly into the surface with the putty knife.
3. Apply a fresh bead
Then apply a new bead.
4. Align and move
Position the workpiece and move it slightly back and forth.
5. Apply pressure
Ensure sufficient contact pressure.
Findings from field trials
In den Versuchen erzielte unbehandeltes XPS die besten Resultate. Aggressives Anschleifen verschlechterte die Ergebnisse teilweise sogar.
Dos & Don'ts
Do
- Note the open time
- Work the adhesive in thoroughly
- Build up pressure
- Prepare for application
Don't
- Forgetting about sun and wind
- Waiting too long
- Unnecessary sanding with XPS
- Working without a test run
Key point: When working with insulation materials, the first 30 seconds often determine whether the job is a success or ends in a mishap.
When should you get tested or seek advice?
Whenever:
- Unknown types of insulation are used
- High temperatures are present
- Special substrates are present
Compatibility of different adhesive systems
Not all insulation materials react the same way to adhesives. Differences in raw materials, density, surface texture, or coatings can affect adhesion.
An adhesive that performs very well on one type of XPS may perform significantly worse on another insulation material. Therefore, preliminary tests should always be conducted when using new materials or applications.
Information on products containing solvents
XPS and EPS are made of polystyrene and can be chemically damaged by unsuitable solvents. This can lead to surface damage, material degradation, and a reduction in strength. At the same time, the quality of the bond is negatively affected, and consistent results are often no longer guaranteed.
For this reason, only adhesive systems that are explicitly compatible with XPS or EPS may be used with insulation materials. If in doubt, compatibility should be verified through preliminary tests.
