AFAIK, There are 2 types of "foam" used in enclosure building.
The first type is rigid foam (usually polystyrene/styrofoam) insulation board, which comes in sheets (white, pink, blue) in various thicknesses. This is used to build structures, can be shaped, then usually covered with tile grout and sealed with several coats of a non-toxic (when dry/cured) sealer to make cleaning easier.
The other kind is spray urethane foam, which can also be shaped after curing, and likewise coated with grout and/or a sealer.
Both are fairly labor intensive. The spray urethane involves potentially harmful fumes before being fully cured. Rigid insulation may require adhesives or silicone caulk with potentially harmful fumes before being fully cured. Some people use either/both in combination, depending on what they're envisioning/building. You can find many examples & discussions about either/both in the
DIY forum and
many "How to" videos on YouTube. :wink:
I'm not aware of a texture spray for this application, but there may be such a thing. :dontknow:
Most of these materials are not great for BDs when freshly applied or exposed, which is why the last step is always sealing with multiple coats of a water-based sealer that's non-toxic
when fully cured.
Personally, I try to stick with natural materials--rocks, river stones/pebbles, brick, patio/landscaping blocks/tiles, slate/shale, cork rounds, tree branches, etc. It depends on your vision & preferences. Lots of ideas in the above DIY forum and
Viv pics only thread in the
Enclosures forum.