While a glass of cold water on a hot day maybe what the good doctor ordered, it’s also true that water can be a menace especially in building construction. In fact it is common knowledge that water can be a source of headache because of a plethora of problems it can cause when it pops up uninvited in your building floors and walls. Apart from posing a great personal health risk, it will leave your floor with tiles that lift and wobble as well as causing damage to the hardwood floor finishing and walls that sports ugly finishing paint blisters and mildews. To ensure that you don’t personally come to acquaint your esteemed self with these pesky problems in your proposed especial building you might want to call home ,here is what you need to know: This menace has solutions that work all the time and revolve around high water table and capillary action of water.
Building on high water table site like a swamp require significant modification to the standard building construction design and work. Because these are grounds that receive and retain excess water during the wet seasons ,the contractor, in the first place must drain the site of all the water .Then you want your house simply off ground which can be accomplished either by utilizing the ground space a garage and locating your living area rooms on first floor. This should isolate your house from the damp ground.
Or you could use suspended concrete floors. A suspended concrete floors is supported by the external and internal load bearing walls and is independent of the ground beneath it. The Contractor will ideally use Pre-cast concrete in the shape and form of a series of Inverted “T” beams and concrete block in fills. When the beams and blocks are craned in place, a mix of moist cement/ sand is brushed over the surface to fill the gaps between them. This grout helps not only to distribute the load across the floor and prevent future movements of the blocks but also it helps keep insects and vermin out. Once the floor receives a finishing work, you can rest assured it will remain dry the rest of it is useful life.
If on the other hand your building construction site has a low water table, then you have to look out for capillary action of water-that is rising damp from small amount of moisture from the ground . Although this can develop into a throbbing pain, its easily forestalled by incorporating the damp proof membrane(DPM) on the floor during construction. In other words before pouring the concrete slab, the Mason must a lay thick polythene sheet membrane over the blinding. Since concrete is not completely waterproof and this membrane is an effective barrier to the rising damp which will keep the floor surface literally home and dry.
It very important to remember that the DPM must overlap the DPC running along the walls to ensure that the superstructure is kept separate from the substructure. This way, no moisture can find its way up to the walls and floors above the ground.
Other suitable damp proof membrane materials are bitumen and asphalt. Bitumen should be applied hot (when it is liquid) and about 3mm thick to a clean concrete slab. Although it is more expensive , it however offers the best protection against rising moisture and is suitable for all floor finishes like cork tiles, Vinyl tiles or pure cement finish. Liquid Asphalt is also , on the other hand applied hot and to a thickness of about 20mm.It can be troweled and does not normally required a separate screed; the finishing tiles are laid directly on it.
To finish off this capillary action of water menace, the Masons must incorporate a damp proof course (DPC) to all load bearing and non-load bearing walls. While load bearing wall requires a foundation trenches the no-load bearing wall requires a thickening in the slab. However in both cases a damp proof course is required under the wall because overlapping polythene membrane need reinforcement along the wall to completely keep them moisture-proof .It is not a good idea to leave the DPC out because it can cause minor expansion of the blocks that can affect the plaster finish occasioning un-slightly paint blisters and poor house interior conditions that may pose a health hazard to the occupants.
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