Will Cement Boards Burn?

The answer is clear: Cement slabs themselves will never burn. This is determined by the chemical properties of its core components, making it a key barrier in building fire protection systems.

The essence of its fire prevention comes from the composition of inorganic materials:

Ingredients: Portland cement (60% -70%), quartz sand, reinforcing fibers (wood/glass fiber).

Key features:

✅  No combustibles: does not contain hydrocarbons, lacks combustion basis;

✅  High temperature resistance: melting point up to 1500 ℃ (far exceeding the fire temperature of 800-1000 ℃);

✅  Zero toxic gas: Only physically dehydrated at high temperatures, without producing toxic gases.

⚠️  Risk in fire (non combustion related)

Explosion risk: When the moisture content inside the board exceeds 100 ℃, vaporization and pressurization may cause surface cracking (especially in oil fires);

Heat conduction: High temperature can be conducted to the combustible structure on the back side (such as wooden keel), indirectly assisting combustion;

Barrier failure: Toxic smoke (from other combustibles) will penetrate and spread after cracking.

 Key to safe use

Anti explosion: Choose thick plates with a thickness of ≥ 12mm or high-temperature resistant coatings;

Sealing: Fill the board joints with fireproof sealant;

Thermal conduction resistance: installation of rock wool backing;

Clear surroundings: It is strictly prohibited to lay flammable materials (cables/insulation layers) on the back.

Conclusion: Cement board is a reliable non combustible material, and its fire resistance value lies in blocking the spread of flames rather than being completely invincible. The combination of scientific material selection and standardized construction can maximize the core value of its "building firewall".