Waterproofing preparatory works – Haunching

Haunching is a process of making the sharp corners into smooth curve in areas like floor & wall junctions and wall & wall junctions.

Purpose of Haunching:

The co-efficient of thermal expansion and contraction is different for floor and wall surface. Due to this the thin waterproofing layer may get damaged and leads to waterproofing failure.

By providing haunching in corner the waterproofing layer will get more area when compared with corner surface (without haunching). It will not lead any damages to waterproofing layer. Also it helps in placing waterproofing layer easily.

Surface preparation:

• Dead mortar chipping to be done and removed of loose materials should be ensured.

• Ensure that the surface is free from oil or grease or any other contaminants

Material preparation:

• Cement mortar should be prepared in the ratio of 1:3

• Any one of the suitable admixture should be added with cement mortar. For example admixture like SBR LATEX should be added with the cement mortar as per the manufacturer’s instruction.

• After mixing the cement mortar should be consumed within 30minutes of its mixing.

Application:

• Water should be sprinkled over the prepared surface; then cement slurry to be applied

• Then the prepared cement mortar to be splattered over the cement slurry

• Then the cement mortar should be finished in the size of 40 to 50mm

• Finishing can been done with PVC pipe for getting smooth curve.

Samples:

First type of haunching is made by providing a curved shape in weak areas (wall and floor junction).

Second type of haunching is made by providing a slope at angle of 45° in weak areas (wall and floor junction).