Fire Door Mastic Nozzle Problems: Too Much, Too Little or the Wrong Bead

Most nozzle problems around fire-door frames fall into three visible patterns: too much material, too little material, or a bead that is simply landing in the wrong place. Those are useful symptoms, but they still need diagnosis. Too much material This usually shows as heavy squeeze-out, material covering the frame face or a bead wider than the accessible joint. Check the nozzle opening first, but also check the joint. A changing gap, rough substrate or missing backing may be forcing the installer to over-apply simply to make the material look continuous. Too little material A thin bead may be caused by a nozzle that is too restrictive, a product/application problem or an attempt to work too quickly over a difficult line. Sika's current application guidance says the nozzle should be cut to the desired bead size and the material applied…