Intumescent Mastic Joint Sealants

We stock a selection of intumescent mastic joint sealants certified to very high specifications from a range of manufacturers such as Dow Corning Geocel, Protecta ASF, Nullifire and Sika Everbuild. Unlike firestopping mastic sealants Intumescent mastic joint sealants expand and fill the joint on contact with fire... explained on Wikipedia like this: An intumescent is a substance that swells as a result of heat exposure, thus increasing in volume and decreasing in density. Intumescents are typically used in passive fire protection and, in the U.S., require listing and approval use and compliance in their installed configurations in order to comply with the law (click here for the wikipedia page regarding the word 'intumescent')