The polymer cement waterproof mortar reacted hollow in the sun corners of some floors.

[Roy]

Our company supplies the materials. However, the polymer cement waterproof mortar we sent to the construction site reacted hollow in the sun corners of some floors. I saw that the waterproof mortar was as crisp as biscuits but not on other floors. I have no idea what’s wrong.

Here is the formula for the waterproof mortar:
Po425 cement:375kg
Heavy Calcium Carbonate:75kg
fine sand:550kg
HPMC:2.5kg
Redispersible Polymer powder:5kg
silicon waterproof mortar: 3kg
PP fiber:1kg

 

[Cassie]

The photos you took are obviously water-stained. It should be drenched before it dries.

 

[William]

Two possible reasons: first, the base layer may have a release agent that has yet to be treated; second, your Redispersible Polymer powder needs to add a bigger amount.

 

[Alex]

First, the ratio of Redispersible Polymer powder is too small that causes the the bad adhesive property;

Second, there is a problem with the interface processing.

 

[Luis]

The base surface looks terrible; is it not clean? It should not pulverize even if it is not cleaned. The reason for the relatively large pulverization is that the water loss is too fast, too many fine powders are added, and the quality of the cellulose ether needs to be better. If it rains before the final set, it is easy to pulverize.

 

[Scott Kaplan]

Partial problems mostly caused by construction.

 

[Ankur]

If the waterproof mortar is cement-based, it must not be drenched with water before hardening. However, it needs to be watered for maintenance after hardening. If the cement is not maintained, it is not only not waterproof but also leaks.