When do you need an ignition barrier? According to the IRC and IBC, an attic or crawl space needs an ignition barrier over the spray foam if the space can be accessed but will not be used for storage or auxiliary living space. You don't need an ignition barrier if the space cannot be accessed without cutting into it, if it is not connected to other spaces, and if it does not communicate with other spaces. Spray Coating Services

These operate connected to a high pressure pump commonly found using 300 to 7,500 pounds per square inch (2,100–51,700 kPa) pressure to atomize the coating, using different tip sizes to achieve desired atomization and spray pattern size. This type of system is used by contract painters to paint heavy duty industrial, chemical and marine coatings and linings.
Wire arc spray is a form of thermal spraying where two consumable metal wires are fed independently into the spray gun. These wires are then charged and an arc is generated between them. The heat from this arc melts the incoming wire, which is then entrained in an air jet from the gun. This entrained molten feedstock is then deposited onto a substrate with the help of compressed air. This process is commonly used for metallic, heavy coatings.[1]
A spray booth is a pressure-controlled closed environment, originally used to paint vehicles in a body shop. To ensure the ideal working conditions (temperature, air flow, and humidity), these environments are equipped with ventilation, consisting of mechanical fans driven by electric motors, and optionally burners to heat the air to speed paint drying. Toxic solvents and paint particles are exhausted outside, possibly after filtering and treatment to reduce air pollution. Prevention of fires and dust explosions is also a high priority. In order to assist in the removal of the over sprayed paint from the air and to provide efficient operation of the down-draft, water-washed paint spray booths utilize paint detackifying chemical agents.
While intumescent coating can be used instead of an ignition barrier or thermal barrier in some cases, the coating itself is not technically either. It does prevent or slow fires, so it has been approved to be used in conjunction with spray foaminsulation as an alternate assembly. The fact that it qualifies as an alternate assembly means that it can be used instead of a thermal barrier or ignition barrier.

During the 1980s, a class of thermal spray processes called high velocity oxy-fuel spraying was developed. A mixture of gaseous or liquid fuel and oxygen is fed into a combustion chamber, where they are ignited and combusted continuously. The resultant hot gas at a pressure close to 1 MPa emanates through a converging–diverging nozzle and travels through a straight section. The fuels can be gases (hydrogen, methane, propane, propylene, acetylene, natural gas, etc.) or liquids (kerosene, etc.). The jet velocity at the exit of the barrel (>1000 m/s) exceeds the speed of sound. A powder feed stock is injected into the gas stream, which accelerates the powder up to 800 m/s. The stream of hot gas and powder is directed towards the surface to be coated. The powder partially melts in the stream, and deposits upon the substrate. The resulting coating has low porosity and high bond strength.[1] Spray Coating