What is Crazing Crack in Plaster?

Crazing is a network of fine cracks usually in the shape of a hexagonal pattern of varying size from 5 to 75 mm. This defect occurs in plastered wall surface because over troweling of rich mix or sand containing excessive amount of dust.

Crazing often occur within a few hours of plaster being applied to the wall and cracks may hardly be visible until dust or moisture makes them noticeable. These cracks normally occurs when a plaster mix with a high cement content is used or the plaster is allowed to dry too quickly.

Crazing crack is a network of fine cracks, usually in a hexagonal pattern, which measure between 5 and 75mm across each hexagon. Crazing often occurs within a few hours of the plaster being applied to the wall and cracks may hardly be visible until dust or moisture makes them noticeable.

Crazing crack in concrete :

Definition of crazing crack :

Formation of fine crack on the surface of concrete material is called crazing crack of concrete.

Example of crazing crack on concrete is crack in a glaze layer.

Some important characteristic of crazing track of concrete :

• The effect of crazing crack is identifiable from another type of fine cracks.
• The effect the refractive indices of crazing crack is different than another region.
• Crazing crack occurred at i) Hydrostatic tension, ii) Reason of very localised welding where the possibility of formation of microvoids, iii) single-ply roofing membrane, iv) joint sealant

How to avoid crazing cracking in concrete :

• Don’t use bleach or chlorine
• Bleach or chlorine can remove the strains but also can damage your ceramic item.

Crazing crack is surface crack of plaster.

It is due to

• Plastic shrinkage.
• Rapid drying
• Temperature variations.
• Chemical reaction.
• Improper grading of material.
• Less curing period.
• Poor construction practice.

Crazing Cracks are cracks on the surface in a hexagonal pattern. It occurs due to shrinkage, not enough curing, acidic water used, and weathering actions.

Measures taken to avoid crazing Cracks:

1)Do sufficient curing during construction.

2)Use sand with 75 mm size particles. Remove all particles greater than 75 mm in size by sieving.

3)Proper workability concrete used.

In addition to all the good answers I read, I would like to suggest we can control cracks by providing grooves in plaster.

Crazing crack is a surface crack that is due to shrinkage and weathering action.

It is a nonstructural crack

Crazing crack may be due to

• Excessive w/c ratio in plaster
• Excessive trowel floating
• Higher temperature
• Weathering effect
• Alternative dry and wetting

To connect it we should repair and maintain regularly with proper care.

Crazing is a system of fine splits, normally in a hexagonal pattern, which measures somewhere in the range of 5 and 75 mm over every hexagon. They are typically exceptionally fine and shallow and don’t reach out through the whole depth of the plaster. They are generally the consequence of over trowelling a rich blend (one with a high cement content) or utilizing sand containing an inordinate measure of dust (over 15% by mass passing a 0,075 mm sieve). Crazing regularly happens inside a couple of hours of the mortar is applied to the divider and breaks may barely be obvious until residue or dampness makes them observable. Craze cracks are of little significance, don’t open and close with time, and can be covered using any quality paint. On the off chance, glass fiber tissue can be applied during the painting activity.

Preventions

1. Make sure that sand to be used does not contain silt or finer particles passing through 75micron. For river sand, should not be more than 8% by vol. and for manufactured sand, should not be more than 5%.
2. Skilled workers should only do this work for better workability and handling.
3. Never sprinkle dry cement on plaster.
4. The base to where the plaster is to be applied should be wet properly. If it left dry, it will soak out moisture from the plaster.

Basically, it's a combination of cement and sand

For example- we can use it over a brickwork which will give good appearance and can also be used as a soundproofing agent