The dosage of cellulose ether (HPMC) in dry mix mortar

With the development of dry mix mortar, the cellulose ether has become an important admixture for cement mortar. Cellulose ethers are used as thickeners and water retention additives in dry mix mortar applications.

The amount of cellulose ether (HPMC) added in dry mortar varies to some extent due to applied grades and construction requirements. In addition, due to the quality difference of cellulose ethers (HPMC) from different manufacturers, the user needs to adjust according to the product standards and construction performance requirements, their own test results shall prevail.

Based on  cellulose ethers (HPMC), we listed the recommended dosages to common applications for reference.

1. Tile adhesive

Recommend dosage is between 0.2%~0.5%.

The MK200P is at high viscosity, which can be at a lower dosage.

2. Grouts or Joint filler

Recommend dosage is between 0.05%~0.1%

3. Plastering mortar

Recommend dosage is between 0.15%~0.2%

4. Wall Putty

Recommend dosage is between 0.25%~0.4%

5. Self-leveling compounds

Recommend dosage is about 0.1%

6. Cement-based/Lime cement-based interface mortar

Recommend dosage is between 0.2%~0.3%

7. Repair mortars

Recommend dosage is about 0.1%-0.2%

8. Vitrified microbead thermal insulation mortar

Recommend dosage is about 0.3%-0.4%

9. EPS thermal insulation plastering mortar

Recommend dosage is about 0.6%-0.8%

10. EPS thermal insulation adhesive mortar

Recommend dosage is about 0.2%-2.5%

Generally, higher viscosities would potentially enable lower dosage rates at the same water retention level and subsequently lower formulation cost. However, viscosities of cellulose ethers in some applications should not be too high as they would have a negative impact on the stickiness of the mortar.