Cementitious fire protection

[edit] Introduction

If a material is known for having properties of cement, it’s called ‘cementitious’. Cementitious materials are one of the core ingredients when making concrete. There are two forms of cementitious material: supplementary cementitious materials and hydraulic cement.

Concrete is of course one of the most common materials in construction. It’s cost-effective, strong, and does not corrode over time. Additionally, the cementitious properties of concrete make it inherently fire resistant.

[edit] Cementitious coating definition

To protect steel elements within a building’s construction, a cementitious coating can be applied. This coating consists of cement or gypsum, which, when wet, forms a durable surface with high fire resistance. Cementitious sprays are applied in multiple layers in order to protect the underlying material. When finished, it forms a barrier that delays the rate of heat transfer in the event of a fire.

[edit] What is cementitious fireproofing used on?

Cementitious spray can be used on most building materials. Its most common application, however, is on structural steel. When applied in multiple layers, cementitious sprays can improve the fire resistance of structural steel.

Regardless of which material it is applied to, there are some key considerations to bear in mind when using cementitious sprays. Firstly, it can be liable to cracking. If the load weight of the protected surface has been miscalculated, the solid surface of the cementitious spray can splinter under the pressure. Secondly, cementitious sprays are not always suitable for high-moisture environments. Moisture can collect between the substrate and the coating, potentially leading to the corrosion of the substrate. For these reasons, intumescent fireproofing is increasingly preferred.

[edit] Cementitious fireproofing vs intumescent fireproofing

Intumescent fireproofing operates very differently from cementitious fireproofing. Instead of being a thick fire-resistant barrier, intumescent paint expands in response to extreme heat, which creates char. The sudden increase in volume through the bubbles acts as an insulating barrier.

So, which is better? Well, the effectiveness of the two are very similar and equally valid when it comes to compliance. The cementitious coatings are more difficult to apply, however. Intumescent coatings are applied like any coating, meaning contractors make light work of it, and it can have multiple layers. Each coating will increase the fire resistance of the structural steel, making this a quick and efficient passive fireproofing method.

Intumescent paint is also more advanced from a technical point, but this doesn’t mean cementitious fireproofing is obsolete. Cementitious coatings are not only still effective but are also cost-effective given their composition of materials.

This article originally appeared on https://clmfireproofing.com/

[edit] Related articles on Designing Buildings

• Cement.
• Cementitious.
• Concrete.
• Fire protection engineering.
• Fire resistance.
• Fire retardant.
• Fire safety design.
• Installing fire protection to structural steelwork (GG 85).
• Intumescent coatings.
• Intumescent strips.
• Metal fabrication.
• Paints and coatings.
• Passive and reactive fire protection to structural steel (IP 6 12).
• Passive fire protection is a vital tool in any fire strategy.