The polyurethane foam is sprayed on over the cured shot-crete and is on the outside of the dome. With all the concern over the health effects from exposure to these substances I am glad there is no possibility of it gassing off inside my home. The one vulnerability of this product is its reaction to UV rays, it is very important to spray elastomeric paint on the exposed foam immediately.
The great thing about knowing what to expect was that I was able to collect the 14 five gallon buckets of elasticized paint from different manufacturers as miss tints. The aim was to spray on a 10mm skin to protect the foam, the buckets were different colours but this was not a concern as I planned to spray a final coat of ceramic insular paint. To buy a five gallon bucket is $280.00 as a miss tint I picked up these buckets for between $15.00 to $25.00 dollars, a sizable savings. Every paint store has a miss tint section, these are cans and buckets of paint that were mixed to the wrong colour. The best stores to pick up five gallon buckets is the industrial outlets that supply contractors. Knowing the amount I required ahead of time gave me a two year head start on collecting my supply