How to Glue Architectural Styrofoam

Enhance your space with delicate, classical architectural details.

Polystyrene foam or architectural Styrofoam is used for ornamental details both inside and outside of buildings. It is popular because it's light, easy to install and inexpensive compared to wood or custom plaster moldings. Use adhesives designed especially for polystyrene foam applications when installing the foam. Cornices and general ceiling work will require the use of a ladder or platform.

Things You'll Need

• Ladder
• Carpenter's level
• Pencil
• Clean rag
• Polystyrene adhesive

Instructions

1. Wipe the surface you will be installing the foam on to remove any dust. Hold a carpenter's level in a horizontal position for mid-wall molding applications and mark the wall with a few pencil dashes where you will be installing the molding or ornament. Hold the molding details in place on the wall to make sure they fit well.

2. Read the instructions thoroughly on your adhesive before beginning. Apply a bead of Styrofoam glue along the outer edge of the contact face of the first piece. If you are using expanding polyurethane foam as an adhesive, apply it on the piece and then flatten it down on the wall by sliding it side to side several times.

3. Press the ornamental piece firmly into place and hold for about 20 seconds. If the details are being applied on an outdoor surface, apply a bead of caulk along the outer edge of the piece where it contacts the building face after the molding detail has fully dried in place. Use mesh reinforcing and adhesive to cover the joint for strength and to prevent moisture from getting behind the ornamental detail.

Tips & Warnings

• Expanding polyurethane foam is usually used for insulation, but is also a popular adhesive for architectural polystyrene trim.

• Check the label on the adhesive before applying it because some adhesives have solvents that will melt through polystyrene. If it's not clearly designated, test it on a piece of scrap polystyrene. Also, some coatings and adhesives require a 24 hour drying period at each step of the process.

References

• Action Foam & Tool: Installation