Building foam - remove stains

Bauschaumflecken is everywhere. But the materials on which the PU foam must be removed, are very different. Here's how to remove stains from construction foam from various materials.

Uses of construction foam

Construction foam consists mainly of the plastic polyurethane. Therefore also the common name "PU foam". The mounting foams are used for completely different tasks:

  • to dam
  • for sealing joints such as construction joints
  • for insulating pipes
  • for gluing panels (ETICS)
  • for underfilling built-in components (baths and shower trays)

It is already clear that construction foam residues can lead to stains on a variety of materials. The special feature of these stains is that they can no longer be removed on numerous materials without much effort.

Remove PU foam stains

Basically, there are several ways to remove PU foam stains. You can mechanically or chemically remove the construction foam, but also protect certain surfaces preventively.

Preventive protection against stains

For example, preventive protection can be provided by a plastic wrap. Also wide plastic adhesive tapes or adhesive films are suitable. Because PU foam adheres very poorly to these surfaces. In addition, you can easily remove the film or tape after foaming.

The mechanical removal of building foam spots

The most common method is the mechanical removal of construction foam. First, the roughly protruding PU foam is carefully cut off with a utility knife (Stanley knife). Depending on the substrate, you can then use a scraper, a soft wire brush (eg with copper wire trim) or fine iron wool. Scrapers, as offered for glass ceramics, are suitable for very hard surfaces. The other two aids depend on the sensitivity of the respective substrate.

Chemically remove mounting foam stains

The chemical removal is basically simple, but carries another risk. If the construction foam spot is on a painted or otherwise treated surface, the solvent may attack it. Especially certain paints can be solved.

It does not matter if you use a special PU foam remover or a solvent like acetone. For example, what should be considered when using acetone, you can read here.

Tips & Tricks

Not only the removal of structural foam spots on components is problematic. Also building foam on the skin or removing PU foam from garments is so complicated and difficult, that we offer you own guides.

Video Board: Removing Expanding Foam Polymer Stains From Cloth