How to Create a Terrarium With Building Foam

Carve the building foam to the desired shape. You can carve holes for potted plants and caves for any animals that might be living in the terrarium. Include plenty of ledges and pockets for plants to root and animals to climb on: There are no limits. Ensure that you have both a finished building foam floor and building foam background, two pieces that fit in the terrarium. If using spray building foam, simply spray the building foam directly onto the glass surface of the bottom and background of the terrarium and sculpt as desired.

Coat the pieces of building foam with the brown or green silicone sealant and place them into the terrarium. The silicone will make the background waterproof. While the silicone is still wet, apply the soil to the surface until no silicone can be seen. If the silicone has dried, apply more silicone before adding the soil. If using spray building foam, paint the foam once it has set, which takes about 24 hours. Apply the soil to the foam in the same manner.

Allow the silicone to fully dry, which will take about 24 hours. Once it is dry and the soil background and floor are set, add any plants, animals and other decorations.