A first timer has hardly ever or rarely heard about these things. The assumption is that this is contractor’s job and he is expert in doing it. The assumption is right but every contractor may not be as expert or as committed as expected. Therefore, it is necessary for you to have bare minimum orientation to the processes so that you should be able to ask the right questions to your contractor which will make him a little more careful.
At Gharplans, we are committed to educating people on the basics of house construction. We continue to bring up those issues which affect a large majority of people and try to prepare you to pre-empt those problems which do not have a solution once they have happened. In this article, we will discuss brick works that is mostly ignored and even if noticed, the mason will try to hoodwink you with the argument that this issue will be fixed with plastering but the fact is that plastering has its limitations and it is quite expensive. Let’s begin with the basics i.e. developing understanding of what a good quality brick work is……
Characteristics of A Good Quality Brick Work:
Good brick masonry begins with buying good quality bricks. Even an expert mason finds it difficult to ensure erection of walls in vertical and horizontal plumb lines if the bricks are not uniform in size and shape. Be watchful to the following aspects when you buy bricks.
- Size, Shape & Color of Good Quality Brick:
Quality bricks are uniform in size, shape, color and texture besides a few other important technical features. The color and texture of bricks may vary depending on the composition of earth/soil used for brick casting. However, texture and color of bricks in one batch must not vary a lot.
The nominal size of a brick as per British Standard and Pakistan Standards is 9×4.5×3 inches. To check variation in size of bricks, you can do the following:
- Lay 10 bricks horizontally with edge to edge joined. Take measurement and divide by 10. If the answer is too far removed from 9, the bricks are inconsistent in size.
- Stack 10 Bricks vertically. Take measurement and divide by 10 and evaluate the answer on the same criteria i.e. if the answer is too far removed from 3 (thickness of the brick), the bricks are inconsistent in thickness.
- Strength of the Brick:
The crushing strength of first-class brick should be 1400-1500 PSI. This test is done under a hydraulic press. However, another way to determine bricks’ strength is to drop one brick over the other from a height of 3-4 feet. If any of the brick breaks, it is likely to be poor quality being below the standard strength.
- How a Good Brick Sounds
Good quality bricks will produce a sharp ringing sound like that of metal or glass when two bricks are struck together in a clapping motion. Sharp sound indicates higher density achieved through use of good clay and thorough baking. A lower density brick will produce a dull sound.
- A Good Brick Absorbs Less Water:
The weight of a good quality clay brick, when immersed in water for prolonged duration (24 hrs.), does not increase by more than 15% of its dry weight. Poor quality bricks will absorb more water.
These are some of the primary parameters for determining the quality of clay bricks which, if observed adequately, will save you from falling into the vicious circle of poor-quality construction.
How Good Brick Work is Done
Now that we are done with identification of good quality brick, let’s consider what entails good quality brick masonry. Here are some of the critical practices that must be ensured.
Bricks Must be Soaked?
Yes! the bricks must be soaked thoroughly before laying. A dry brick will suck the water from mortar rendering it ineffective in bonding the bricks together which will ultimately result in compromised structural strength. Ideally, the bricks should be immersed in clear water for at least an hour before starting work. Mere sprinkling water on stack of bricks with a hose is not very effective way of soaking the bricks.
From Inside or Outside?
The mason, while laying bricks for erection of structure, stands on one side and does his job. There may be more than one mason working simultaneously. You must make sure that entire brickwork is carried out from one side i.e. either from inside or outside of the building lines. It must not be allowed that one mason is working one side of section while the other one on the other side. We have also observed that when they start work from the ground, they working from the outside which gives neater finish on the outer side but once they reach the level of lintel beam, they would start working from inside. This practices significantly compromises precision in verticality and must be strictly prevented. This will ensure that the rough or neat side of the brick laying is consistent throughout the building.
Such consistency is sure to give you good vertical alignment of various sections of walls which, besides being structurally more stable, will ultimately result in significant savings in plastering. Why saving in plastering? Because if two vertical sections are displaced by say ½ inch, they have to be covered with extra ½ inch thick plaster layer. Imagine the size of the wall section, you will easily know how much you are going to spend unnecessarily because of this small negligence.
How Much in a Day?
Make sure that no more than 4 feet of wall is built in a day. If you do, the weight of the bricks may cause the fresh soft mortar to sag. The mortar shrinks also as it cures. Now this shrinking and sagging effect put together can cause significant deflection of the structure. Before starting works the next day, check the verticality with plumb bob or spirit level. If there is little bit of deflection, it can be fixed at this stage by pushing and tamping the small section of wall back in plumb and perpendicular. A good and committed mason uses plumb bob very frequently not just on top few courses but all over the built section.
How Thick Should be the Mortar Layer?
10-12mm (1/2 inch) thickness of the mortar joint is the optimal. Thicker mortar layer is 30% less strong. Besides, thicker joint will have higher coefficient of shrinkage which will ultimately result in compromised stability of the structure.
Mortar Joints Should be Aligned
You must be watchful that the mortar joints in each course of bricks are near-perfect in alignment. As shown in the picture here, alignment of the joints is the indication of stable and strong masonry work.
This is where the quality of brick comes in. If bricks are not in uniform shape and size, maintaining this alignment become difficult for the mason. He would have to use thicker or thinner mortar joint to maintain the alignment which would affect the quality of the works.
What Should You Watch to Ensure Good Masonry?
To summarize what we have discussed in previous sections, you must watch that mason is laying brick in a straight line which is normally managed by tying a thread along the course of brick in a straight line. Also watch that each course of bricks is uniform in terms of spacing of one brick to the other. The top and bottom level of each course must look uniform with naked eye. The thickness of mortar in joints is equal both horizontally and vertically. See how often the mason is using the plumb bob and spirit level ensure accurate alignment and levels.
Mortar must be mixed thoroughly before application is started. Bricks must be thoroughly soaked before setting in the mortar and cured at least for 7 days. Freshly laid brick should be covered with a plastic sheet if rain is coming.
By following these tips, you can ensure your brick work to be precise which will prevent and pre-empt any snags to be fixed later (only to limited extent).
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