How to avoid subsidence in constructing polymer cement waterproof mortar in window joints?

[Alex]

According to the building exterior wall waterproof construction specification, the gap between the door and window frame and the wall is filled with polymer cement waterproof mortar. The gap is about 20mm high and as wide as the window frame. Workers use filling guns to fill in the joints. After filling in the well-mixed mortar in 1 minute, it collapses and falls due to gravity. If reduce water consumption, workers cannot extract it due to the high viscosity. I want to figure out how to improve the formula. It was used in facade construction before with a thin layer of 6mm, and there was no problem. Thank you!

 

[Ankur]

You’d better to provide the ratio. If the gap is large, the proportion of coarse aggregate should add more, and you should appropriately reduce the proportion of fine cement powder. I don’t know the content of these ingredients in your water-reducing agent, so it’s hard to say.

 

[Cassie]

Increasing the particle size of the graded aggregate, and it must be dense and water-repellent. The amount of water-reducing agent should be appropriate, similar to structural repair mortar.

 

[Roy]

Fill the large gaps first and then fill with mortar.

 

[Luis]

My idea for door and window caulking is waterproof mortar with lightweight, high adhesion, and water-repellent. It has better constructability, no sag, and low labor intensity for handling and construction than heavyweight.