Walling for the ground floor starts
Now that the foundation, complete with a ground floor slab was in place, it was time to put up walls. Samson and Delilah agreed that it was not yet time to borrow. So they sold a plot of land that Delilah’s late father had bequeathed to her for the capital into the house. The Merabu House, as they lately called their dream home, should not be sold off for failure to pay off the ill-timed high-interest-rate mortgage. As usual, they consult- ed Erifaz the quantity surveyor, who ascertained that the schedule of materials and labour as proposed by George the foreman was adequate. Window-shopping for bricks, cements, lime and sand was done by Delilah and George. One Mon- day morning at the beginning of the month, walling started.
Walls were needed to separate the inside and the outside of the house, a fact the couple did not need to grasp from their friendly consultants.
George the foreman followed the drawings to the core by building all the external walls as load-bearing. These 230mm-thick walls were meant to carry the roof forces and to withstand wind and other forces. There was also an internal 230mm- thick load-bearing wall which cut along the middle of the house. It was meant to reduce the internal span and make the timber slab between the ground and first floor cheap and economical. The rest of the internal walls on the ground floor were non-load-bearing. Abdul Kizito the engineer explained to Delilah that load-bearing walls were carrying the weights. The non-bearing walls like the one in the kitchen store was only for partitioning the space. It could be removed without causing any collapse any time. These thin walls could stand independently of the main structure.
Kizito and Cathy had advised that the walls be built out of the clay burnt bricks, 215x 102.5×6.5mm in size. This was the 8x4x3inch brick, as commonly known by the bricks’ sellers. The wall width, without external plaster was to be 215mm. With the plaster either side of the brick the wall thickness was expected to be about 250mm. Delilah asked why the confusion of both the metric and the British systems operate on one sovereign state, but Abdul said that question would be best answered by a combination of policymakers, the professionals and the Uganda National Bureau of Standards. He however agreed that having no or little standardization of construction materials in the metric system was costing the economy a lot.
Abdul Kizito had advised Samson to buy the locally burnt clay bricks because in spite of their uneven surfaces they were still the most cost-effective. They were readily avail- able from the Mukono, Kajjansi and Gayaza areas of Kampala. They were strong enough to withstand loads from the roof and floors. They were equally stable, resisting wind and roof pressures. They could resist effects of rain and they kept the interior cool due to their good thermal properties. Apart from being durable, they were also highly fire-resistant. Kizito had compared all these properties and the associated costs with the concrete blocks and the Kajjansi factory-made bricks before making this recommendation.
The biggest disadvantage the walling team endured was the increased plaster surface and time as they had to cover vast extra areas due to using the unstandardized bricks with uneven surfaces. In order not to have a problem of different sizes, Eridad the quantity surveyor had ad- vised Samson to buy all the bricks needed for walling at a go and from one source. He knew that different local brick manufacturers made different sizes of bricks, the so- called 9x5x4 or 8x4x3 or 8x5x4 inches! This is one of the reasons why the construction industry makes losses which affect the entire economy.
George and his team of builders used mortar to join the bricks together. They mixed cement, lime and sand and used the mortar to provide a level bed for the bricks to sit on and maintain horizontal and vertical stability. “The water-resistant filler between the bricks also prevents penetration of water and air into the interior of the house,” Kizito explained.
George ordered the bricklayers to use a mix of 1:3 of cement and sand by volume because this would be the strong-enough paste for the storeyed house. However, he also told the lads to add lime because, apart from making it easier to spread the mortar, it reduced shrink- ages and lengthened the time the mortar was still pliable or workable. In other words, the unused mortar did not harden too quickly before it was used for jointing.
The builders used flush joints, whereby the mortar was lev- elled with the bricks since the walls were to be plastered on both sides. Other options would have been to have weather-struck or half-round or recessed joints.
Bonding of the bricks
There is a way masons put bricks on top of others to form the straight vertical walls and corners. George read the detailed drawings and discovered that Kizito had preferred the English-bond type. This combined the head- er and stretcher bonds. The masons laid the foot course with two rows of stretcher bonds without using wall ties. The next course consisted of headers that were laid across the stretchers. One header lay on the centre of each stretcher and over each joint between the headers.
In this way, Kizito swore that the lead-bearing walls produced a more interesting pattern and a very well-bonded house. The workers had wanted to use the Flemish bond but the supervisors refused. In the Flemish bond, both headers and stretchers would have been used in the order: a header, two stretchers side by side, and a header, and so on.
Openings and corners
The builders had to stop the brickwork at door and window openings, or to change direction at the corners. They had to ensure that the English bond remained strong and appeared neat and good. They cut the bricks in half along their length and built them into the wall at half-brick length from the corner or quoin. The cut brick is called a closer.
In all this walling, Samson and Delilah availed workers with tools and equipment. He repeated the good gesture by selling to the workers the tools at a slightly cheaper rate. Both parties agreed that the worker would buy another one out of his money, if he lost the tool. These were: shovels for mixing the mortar, pointing trowels, mortar boards, spirit levels, metal pegs and lines, mixing boards, hand-brushes and a bowls of water.
Samson had availed all the cement in bags, sands, bags of hydrated lime and clean water. In addition, he had to arrange for enough timbers and eucalyptus poles which were used for scaffolding (erection of temporary stands) to use for climbing and safety as workers build higher.
Walling with English bond method
Applying damp-proof courses
Samson and Delilah’s house would be vulnerable to damp from water that seeps up the walls of the house if damp-proof course (dpc) sheets were not appropriately placed. The dpc was placed on all the external walls to stop water from rising into the interior and upper parts of the house. Samson had observed that some houses of colleagues were damp and he took pains to ask Kizito and Cathy how to prevent it from happening on his.
Firstly, Kizito explained that the dpc has to be of approved good quality bitumen-based material, wide enough to cover the width of the external wall. It was rolled out on a brick wall that was 150mm above the ground and laid in a mortar bed. Where there were joints, they were lapped at least 150mm. “The height above the ground prevents heavy rain water from splashing the wall and bypassing the dpc,” Kizito explained. Where there were openings in the brick wall for doors or windows, either eucalyptus timber lintels or the ring beam were used. By this time, Delilah was beaming with happiness as she went through the sitting room, the dining room, the kitchen and the guest bedroom. She could not climb up because there was no staircase and nowhere to go anyway. What pleased her more was the spacious kitchen, the big kitchen store and the wide verandah to the kitchen. She could clearly see the space for basking out as she conversed with her friends over washed and ironed clothes. And so, the walls on the lower ground were done up to the ring beam level, awaiting construction of the ring beam and continuation of walling for the first floor.