Problem Solving Forum
July 1 - July 5, 2019
Where would you use epoxy and cementitious intumescent coatings?
David Grove of The Grove Real Estate Group on
July 12, 2019:
Mr. Dobrosielski stated it best in that cementitio ...read more Mr. Dobrosielski stated it best in that cementitious materials are not intumescent materials. They are totally different. Cementitious are barrier materials. Intumescent coatings are reactive in that they expand to create an insulating layer of ash between the heat and the surface being protected. There are different considerations that must be looked at for both. Weathering is a factor as low-density cementitious materials do not weather well and are friable. High-density cementitious materials add significant load to the structure. All cementitious materials are difficult to apply in restricted access areas and may contribute to accelerated corrosion from moisture retention. Simply, cement holds water, potentially putting the structure in an immersed condition for extended periods of time. This created significant problems in some chemical plants. Intumescent coatings are expensive to apply because of multiple applications and once expanded, can detach from the surface if hit by water (think of the “Snake” firecracker that expands when lit and how the ash can be easily broken up). Epoxy types weather extremely well. Latex-based acrylic types do not, but they can be topcoated to seal them, for a very limited exposure, but any void in the seal will allow a problem to develop with the protection. A close and detailed inspection is key to all fireproofing material applications,, since many difficult-to-access spots, if not coated correctly, will greatly reduce the final rating that was required to be achieved.
Stephen Dobrosielski of Retired on
July 8, 2019:
The term "intumescent" refers to a coating materia ...read more The term "intumescent" refers to a coating material that expands when exposed to high temperature from a fire. This large expansion (of large decrease in material density) provides fire protection. Cementitious fireproofing is not an "intumescent" because it does not react in that manner - it simply insulates the steel surfaces to prevent steel temperature increase. Typically, epoxy intumescents are used in facilities that would experience a "rapid rise" fire due to the presence of a hydrocarbon fuel source that burns at high temperatures. Acrylic intumescents are used in facilities where that hydrocarbon fuel source is not typically present. Similarly, cementitious fireproofing is used in both situations with higher density materials used in hydrocarbon fire potential facilities and lower density materials used elsewhere. The devil is truly in the details, both for the specifier and the contractor.
Ricardo Márceles of Pintuco on
July 3, 2019:
The epoxy or cementitious intumescent coatings are ...read more The epoxy or cementitious intumescent coatings are used depending on the massiveness of the supporting structural element and also of the place where it is to be applied; For example, beams or columns that are going to be visible, as long as their massiveness allows it, can be coated with intumescent epoxy type, which offers a more aesthetic finish and can be coated with finishing paints. For those areas where it will not be visible and their masses require high thicknesses of dry film, it is preferable to place cementitious intumescents. Additionally, it is important to evaluate costs, given that at high thicknesses it is more viable to work with cement-type intumescents.