formulations so as to provide the desired consistency the lagging adhesive is preferably a fire rated water based rubber type treated in a manner so that its burning rate is extremely slow to non existent a typical commercially available lagging adhesive is benjamin foster 81 42 w in one preferred embodiment the lagging adhesive has a consistency of latex paint so as to provide resiliency and pliancy in to the end product in another embodiment as further described below the adhesive may preferably be a fireproof plaster paris type material or cement 36 so that once the adhesive has solidified the resultant blanket and sheet material is semi rigid to rigid in form rather than resilient the adhesive also functioning as a stiffening agent this type of adhesive binder would be a material such as a mineral material that will hydrate that is take on water to solidify examples of such material 36 would be plaster of paris or portland cement these materials not only bind the fibrous and expandable minerals 12 and 18 together but also bind them to the substrate 20 as well in this instance water is sprayed from nozzles 27 to hydrate the cement in all cases no matter what type adhesive binder used in the present invention it would be applied in such a manner in velocity and amounts to ensure intimate contact and admixture with all fibrous and expandable mineral materials 12 and 18 along with the substrate materials 20 downstream from the forming chamber 24 the fibrous matrix 32 adhered to the substrate 20 passes into a.