A spray unit for a remotely operable spray apparatus and apparatus for spraying thermally insulative material

There is provided a spray unit for a remotely operable spray apparatus. The spray unit (4) is configured to spray a material having first and second material components. The spray unit comprises a first material inlet (17) for receiving the first material component, a second inlet for receiving the second material component (18) and a spray component (20) comprising a mixing chamber and a spray orifice (19). The spray component is moveable via a pneumatic actuator which is controlled by a remotely operable electronic actuator to allow the inlets to be in fluid communication with the mixing chamber such that the material is sprayed out of the spray orifice. The actuator also moves the component to a non-spraying position. The spray unit may be attached to a robotic device used to insulate underfloor cavities. The unit may be coupled with a sensor unit which may have a rotatable housing and be extendable. The sensor unit may include a protective film assembly for removing dirt and debris from the sensor.