Sunk slab in bathrooms: a sunk (sunken or depressed) slab is the part of a floor slab under a bathroom or toilet that is cast lower than the rest of the floor. The drainage pipes from the WC, floor trap and basin run inside this depression and are buried in filling, so the bathroom floor…
Damp proof course (DPC): a DPC is a thin waterproof layer laid across the full thickness of the walls at plinth level. It stops moisture in the ground from soaking up into the walls (rising damp). In Indian houses it is most often a 40–50 mm layer of cement concrete (about 1:1.5:3 or 1:2:4) with…
How many days to cure concrete? IS 456 asks for exposed concrete to be kept continuously moist for at least 7 days with ordinary Portland cement (OPC), and at least 10 days with blended cements such as PPC or mixes with fly ash or slag. In hot, dry weather the minimum rises to at least…
Cement plaster vs gypsum plaster vs POP punning: cement plaster is a sand-cement coat, about 12–15 mm inside and thicker outside. It is strong, tolerates moisture and works everywhere, but it needs curing and a smoothing layer before paint. Gypsum plaster is a factory-made plaster applied straight onto brick or block in one coat. It…
Isolated vs combined footing: an isolated footing is a separate concrete pad under a single column. It is the simplest and most common footing in RCC houses on reasonably good soil. A combined footing is one larger footing that supports two or more columns. It is used when columns are so close that their isolated…
Lintel vs beam: a lintel is a short horizontal member over a door or window opening. It carries only the wall above that opening and passes it to the wall on either side. A beam is a main structural member that spans between columns or walls and carries slabs, walls and everything above them; it…
Plinth beam vs tie beam vs grade beam: all three are RCC beams near the base of a building, but they sit at different levels and do different jobs. A plinth beam runs at plinth level, just below the ground floor. It connects the columns and carries the ground-floor walls. A tie beam connects columns…
Load-bearing vs framed structure: in a load-bearing structure, the walls themselves carry the roof and floors down to a continuous foundation, so the walls are thick and cannot be removed freely. In a framed structure, an RCC skeleton of columns, beams and slabs carries the loads to footings, and the walls only fill the gaps….
AAC blocks vs red bricks: AAC (autoclaved aerated concrete) blocks are large, light blocks, roughly a third of the weight of red brick for the same volume. They insulate heat better and build walls faster with less mortar. Red clay bricks are heavier and stronger per unit, absorb knocks and fixings better, and suit load-bearing…
Fe500 vs Fe550 TMT bars: the number is the minimum yield strength in N/mm² under IS 1786: Fe500 bars yield at 500 N/mm² or more, Fe550 at 550 N/mm² or more. Fe550 is about 10% stronger, so a design can sometimes use less steel, but it stretches less before breaking: its minimum elongation is 10%…