WALL CRACKING AFTER CONSTRUCTION......

The wall cracking are define as a line appeared on the surface of the plastered wall after construction.The main reason are the expansion and shrinkage factor of the motar and p;astering material.There are two type cracking 1.structural cracking 2.non structural cracking but for this topic only the non structural  will be discussed.

Shape of cracking

1. Vertical and horizontal
2. Jagged,Step ladder and diagonal cracking
3. Map cracking

Type of cracking

1. Hairline cracking or minor
2. Medium wide cracking
3. Major cracking

Contribution Factor of cracking

1. Exmet wire every 4 layer
1. Installation of exmet wire between 4 layer and connect to the column is to reinforce the wall from tensile load and sudden loading to the wall.Also to avoid unsightly cracking due to settlement.
2. Quality and thickness of motar,
1. Motar must be posses adhesion character and also a have a good resistance to the water.The right mix between cement,water and sand also the main reason to avoid cracking.Sometimes a motar too dry and too wet  and allow for shrinkage and expansion of joint. Motar also have a compressive strength and test should be carried out and the right thickness can also avoid cracking.Too thin and too thick also contribute the horizontal cracks appeared.
3. Straight  jointing between layer
1. Every layer of bricks are laid in staggered between top and bottom layer.All type of bond that the vertical joint between layer are not straight and at least the position of vertical joint meet at half the bricks length.If the vertical joint are straight through all the layer,the vertical  joint will appeared.
4. Stiffener every 3.0 in vertical and horizontal direction
1. To avoid continues cracking a cut of point must be applied.Every 3.0 m length in vertical a stiffener will construct and over 4.0 m height a tie beam will be construct.
5. Quality of plastering
1. Plastering mix are mix from cement,sand,water and hydrated lime.The right ratio of mix will avoid of cracking and shrinkage problem and one thing about the type of sand are used.The fine sand will used and not a coarse sand.The ratio mix of plastering is depend on the usage whether internal or external  or ceiling.plaster.
6. Thickness of plastering
1. The standard thickness of plastering are between 12 mm to 15 mm.The uneven surface of the wall are the factor that the thickness of the plastering are uneven also.The line of cracking are always found at the slim thickness of plastering and too thick of plastering.

The above 6 factors are always contribute to the cracking of the wall after construction and also the settlement and failure of the concrete structure like beam and foundation also contribute the cracking at the wall.There are many methods to rectify the cracking.Filler with the grouting cement are the common method or hacking the old plastering at the cracking and put a wire mesh at the cracking line and making good with a normal plaster or plastering mix with a hydrated lime.Hairline cracking can be demolish with the white paint filler before applying the undercoat paint.