Odisha CHSE +2 Vocational Building Maintenance cheat sheet

Standard brick size in India (IS 1077): 190 × 90 × 90 mm modular; conventional field size 230 × 110 × 70 mm including mortar joint; 10 mm joint assumed.

Brick water absorption limit for first-class bricks: not more than 20% by weight after 24 h immersion; compressive strength of first-class brick ≥ 10.5 N/mm² (IS 1077).

Ordinary Portland cement grades: OPC 33, 43, 53 - the number is the 28-day compressive strength in N/mm² of a 1:3 mortar cube; initial setting time ≥ 30 min, final setting ≥ 600 min.

Bulking of sand: volume increase of moist sand due to surface film of water; typically 20–30% at 4–6% moisture; measured by comparing loose volume of moist and dry sand in a measuring cylinder.

Concrete nominal mixes (IS 456): M5 = 1:5:10, M7.5 = 1:4:8, M10 = 1:3:6, M15 = 1:2:4, M20 = 1:1.5:3, M25 = 1:1:2; M20 and above must be design mix for reinforced work.

Slump test (IS 1199) measures workability: typical slumps - 25–75 mm for normal RCC, 75–125 mm for heavily reinforced sections; slump cone dimensions 100 mm top, 200 mm bottom, 300 mm height.

Foundation rule: minimum depth of footing below ground ≥ 500 mm; width of footing such that pressure on soil does not exceed safe bearing capacity (SBC) in kN/m².

Timber moisture content for structural use: 12–15% for internal joinery; seasoning reduces shrinkage, warping and improves strength and paint adhesion.

Cement:sand mortar ratios: 1:3 for structural/load-bearing masonry and plaster of external walls; 1:4 for general brickwork; 1:6 for internal plaster and non-load-bearing partitions.

English bond: alternate courses of headers and stretchers; strongest bond for walls; used for walls of thickness ≥ 1 brick.

Flemish bond: each course alternates header and stretcher; more decorative than English bond but weaker; headers called 'bastard' headers when not full brick.

Stretcher bond (running bond): all bricks laid as stretchers; used for half-brick (115 mm) partition walls; weakest in longitudinal direction but economical.

Queen closer: a brick cut longitudinally into two halves; used to adjust bond at corners and to break the continuity of headers in Flemish bond.

Mortar joint thickness in brickwork: 10 mm standard; range 6–12 mm; thicker joints reduce strength and increase shrinkage.

Rule for wall thickness in bricks: 1 brick wall = 230 mm nominal, 1½ brick = 345 mm, 2 brick = 460 mm; use modular 190 mm brick with 10 mm joint for 200 mm wall.

Quoins: corner stones or bricks laid in alternate courses to tie the two faces of a wall; essential at all wall junctions and openings.

Raking bond: bricks laid at an angle to the face to tie inner and outer leaves of a cavity or thick wall; herringbone and diagonal types.

Random rubble masonry: stones of irregular size laid with mortar; coursed rubble is stronger because courses are levelled at intervals; through stones every 1.5 m in height.

Plaster thickness: 12 mm for internal brick walls, 15–20 mm for external walls, 6 mm for ceiling; two-coat work = 10 mm undercoat + 6 mm finish (external 12 + 8 mm).

Mortar ratios for plaster: 1:4 or 1:5 for external, 1:6 for internal; cement plaster must be cured for at least 7 days to prevent shrinkage cracks.

Base coat (undercoat) should be roughened with a scratching tool to give key; finish coat applied after initial set of undercoat, not after full drying.

Corner beads and chicken mesh at junctions of RCC and masonry prevent cracking due to differential movement; minimum 150 mm mesh width each side.

Punning or three-coat plaster: 12 mm backing + 6 mm floating + 3 mm finishing coat of lime or gypsum; used for high-quality internal surfaces.

POP (plaster of paris) setting time: 5–15 minutes; used for decorative cornices and mouldings; must not be used in damp locations.

Stucco/roughcast finish: mortar dashed onto surface with a scoop or machine; gives weather resistance on external walls.

Whitewashing: 1 kg lime + 0.5 kg gum + water; two or three coats; used on internal walls before distemper for economy.

Soil pipe carries human excreta from water closets; waste pipe carries sullage from sinks, baths and basins; both discharge to the drainage system.

Vent pipe (anti-siphon) equalises pressure in the drainage stack; its top must be at least 150 mm above the roof and away from windows; diameter not less than half the soil pipe.

Trap seal depth: 50 mm minimum for water closets and floor traps; 75 mm for gully traps; seal prevents sewer gas entry.

One-pipe system: soil and waste discharge into a single vertical pipe, with a vent pipe; two-pipe system: separate soil and waste stacks with separate vents.

Gradient for horizontal drain pipes: 1 in 40 to 1 in 60 for 100 mm pipe; 1 in 60 to 1 in 80 for 150 mm pipe; minimum self-cleansing velocity 0.75 m/s.

Inspection chamber (IC) spacing: not more than 30 m on straight runs; manhole spacing 100–150 m; provide at every change of direction and junction.

Water supply pipe sizes: 15 mm for a single tap, 20 mm for a bathroom group, 25 mm for a full house; minimum residual pressure at tap 0.05 MPa (5 m head).

GI pipe jointing: threaded joints with white lead or PTFE tape; CI pipe jointing: lead caulking or rubber ring push-on joints; PVC jointing: solvent cement.

IS 732 wiring colours: phase red/yellow/blue (three-phase) or brown (single-phase), neutral black or blue, earth green or green-yellow.

Earth wire resistance: not more than 1 ohm for a single earth electrode in ordinary soil; use copper plate or GI pipe electrode; test with earth tester.

MCB (miniature circuit breaker) rating must not exceed the current-carrying capacity of the cable it protects; typical lighting circuit 6 A, power circuit 16–32 A.

ELCB/RCCB: earth leakage circuit breaker trips at 30 mA for human protection; 100 mA for fire protection; test button must be pressed monthly.

Lighting circuit load: maximum 800 W or 10 points per circuit; power circuits separate; total connected load determines main switch and meter size.

Conduit wiring: PVC conduit concealed in wall with minimum 2 mm wall thickness; bending radius ≥ 6 times conduit diameter; draw box every 10 m or two 90° bends.

Socket outlet height: 1.2 m above floor for general use; switch height 1.2 m; kitchen counter sockets at 1.1 m; all sockets must have a third earth pin.

Earthing types: plate earthing (copper 600 × 600 × 3 mm or GI 600 × 600 × 6 mm) buried 3 m deep with charcoal and salt; pipe earthing with 38 mm GI pipe 4.5 m long.

Standard door sizes (IS 10021): residential 900 × 2000 mm or 800 × 2000 mm; bathroom 700 × 2000 mm; the door leaf thickness 35–40 mm.

Window sizes: 600 × 600, 900 × 900, 1200 × 1200 mm; sill height 900 mm for living rooms, 1200 mm for bathrooms, 750 mm for kitchens.

Timber joints: mortise and tenon for frames; dovetail for drawer corners; halved joint for lengthening; dowel joint for concealed work; lap joint for general framing.

Seasoning of timber: air seasoning takes 6–12 months; kiln seasoning 7–14 days; moisture content for joinery 10–12%.

Door frame: 100 × 63 mm or 125 × 75 mm section; holdfasts (MS flat 300 mm long) fixed at bottom and top on each side into masonry.

Panelled door: stiles and rails 100–125 mm wide; panels 12–15 mm thick; minimum 4 panels for a 900 mm door; flush door: 35 mm thick with blockboard or plywood core.

Shuttering plywood for formwork: 12–19 mm thick; reuse 6–8 times if oiled; film-faced plywood gives smooth concrete finish.

Wood preservatives: coal tar creosote for external timber; copper chrome arsenate (CCA) or boric acid for internal; apply two coats on all surfaces before fixing.

Paint coverage: 1 litre of emulsion covers 8–10 m² per coat; enamel 10–12 m² per coat; primer 10–12 m² per coat; allow 4–6 h drying between coats.

Surface preparation: remove loose paint, grease and dust; sand paper to key the surface; apply primer within 24 h of preparation on wood and steel.

Paint system for wood: primer + 2 coats of undercoat + 2 coats of enamel; for steel: red oxide primer + 2 coats of enamel; for plaster: alkali-resistant primer + 2 coats of emulsion.

Varnish: transparent finish for wood; types - spar varnish (external), polyurethane (hard wearing), shellac (French polish). Apply 3–4 coats with sanding between coats.

French polish: shellac dissolved in methylated spirit; applied with a rubber pad in circular motion; gives high gloss on internal furniture.

Distemper: water-based, economical for internal walls; 1 kg covers 4–5 m²; not washable; dry distemper must not be used in damp areas.

Paint defects: blistering from moisture under paint; flaking from poor adhesion; chalking from excess pigment; sagging from over-thick application.

Lead in paint: avoid in children's rooms and food areas; use lead-free or low-VOC paints; ensure ventilation during application.

Crack classification: hairline < 1 mm, fine 1–2 mm, medium 2–5 mm, wide > 5 mm; structural cracks wider than 2 mm need engineer inspection.

Repair of cracks: V-groove the crack, clean, prime, fill with epoxy or non-shrink grout; for masonry cracks use cement mortar 1:3 with chicken mesh.

Grouting: cement grout 1:1 with water-cement ratio 0.4–0.45; use non-shrink grout for machine bases and column jackets.

Waterproofing repair: remove damaged layer, apply cementitious waterproof coating 2 coats (1.5 kg/m²), or APP membrane with 100 mm overlap.

Repair of spalled concrete: chip to sound concrete, clean reinforcement, apply rust converter, prime with bonding agent, fill with polymer-modified mortar.

Renovation sequence: structural assessment → demolition → new work → services → finishes; obtain structural clearance before removing load-bearing elements.

Retrofitting: jacketing of columns with 75–100 mm concrete; FRP wrapping for shear strengthening; shear keys for beam-column joints.

Maintenance schedule: inspect roof drains before monsoon; repaint external surfaces every 5 years; check plumbing joints annually; test fire alarms monthly.

Brickwork volume: length × height × thickness; deduct openings > 0.1 m²; add 5% for wastage; number of bricks = volume / volume of one brick with mortar (0.002 m³ for modular).

Plaster quantity: area × thickness; cement required = volume × dry density factor (1.3) × cement ratio / sum of ratios; 1 bag cement = 0.035 m³ = 50 kg.

Concrete quantity: length × breadth × depth; dry volume = wet volume × 1.54; cement bags = dry volume × cement ratio / sum of ratios / 0.035.

Steel reinforcement: weight = d²/162 kg/m where d is bar diameter in mm; e.g. 12 mm bar = 0.888 kg/m; add 5% for laps and wastage.

Measurement units: earthwork in m³, brickwork in m³, plaster in m², painting in m², steel in kg or quintal, doors/windows in number or m².

Rate analysis: cost of materials + labour + plant + overheads (5–10%) + contractor profit (10%) + GST as applicable; labour constants from IS 7272.

Centre line method: suitable for walls of same thickness; total centre line length × width × depth; deductions at junctions to avoid double counting.

Long wall-short wall method: long walls measured out-to-out, short walls in-to-in; used when wall thicknesses differ; cross walls deducted separately.

Personal protective equipment: helmet, safety shoes, gloves, goggles, ear plugs, dust mask, and full-body harness for work above 1.8 m.

Scaffolding: working platform width ≥ 800 mm; guardrail at 1 m and 0.5 m; toe board 150 mm; inspect before each shift; tag system for safe/unsafe.

Excavation safety: shoring for depths > 1.5 m; ladder every 7.5 m; keep spoil at least 1 m from edge; test for gas before entry.

Electrical safety on site: 30 mA RCCB on temporary supply; no bare wires; lockout-tagout before maintenance; earth all metal equipment.

Ladder rule: 4:1 slope for leaning ladders; extend 1 m above landing; do not work from top three rungs; secure at top and bottom.

Tool safety: chisels and screwdrivers must have mushroomed heads ground off; grinding wheels rated for the machine speed; guards in place on circular saws.

Waste management: segregate construction and demolition waste into concrete, brick, timber, metal and packaging; reuse rubble as filling; dispose at authorised sites.

Dust and noise control: wet cutting of concrete and bricks; use silencers on compressors; restrict noisy work to daytime; monitor noise at 90 dB(A) action level.

First aid: keep a stocked first-aid box; emergency numbers displayed; trained first-aider on site for every 50 workers; report all accidents in the accident register.

Cement bags stored on wooden pallets 150 mm above floor, 300 mm from walls; stack height not more than 10 bags; use oldest stock first; shelf life 3 months for OPC.

Aggregate sizes: fine aggregate passes 4.75 mm sieve; coarse aggregate retained on 4.75 mm; maximum size 20 mm for RCC, 40 mm for mass concrete.

Water-cement ratio: 0.45–0.50 for normal RCC; 0.40 for water-retaining structures; each 0.01 increase reduces strength by about 1–2%.

Concrete curing: 7 days for OPC, 10 days for blended cement; keep surface moist; curing compounds used where water is scarce.

Damp-proof course (DPC): 40–50 mm thick cement concrete 1:2:4 with waterproofing compound at plinth level; must be continuous across all walls.

Plinth level should be at least 450 mm above ground and 150 mm above the road level to prevent water entry.

Lime: fat lime slakes with 2–3 times its volume of water; hydraulic lime sets under water; used in whitewashing and mortar for old buildings.

English bond rules: headers and stretchers alternate course by course; at corners, a quoin header and queen closer in the following course; no continuous vertical joint.

Brick masonry in mud mortar is used in low-cost rural construction; cement mortar 1:6 for load-bearing walls, 1:4 for piers and columns.

Cavity wall: two leaves 90–100 mm thick separated by a 50–75 mm air gap; wall ties of galvanised steel at 900 mm horizontal and 450 mm vertical spacing.

AAC blocks: density 550–650 kg/m³; compressive strength 3–5 N/mm²; mortar joint 3 mm with thin-bed adhesive; good thermal insulation.

Stone masonry: through stones (bond stones) of full wall thickness at 1.5 m intervals in both directions; hearting with small stones and mortar.

Honeycombing in masonry: fill joints properly; mortar should be stiff, not sloppy; soak bricks in water before laying to prevent suction of mortar water.

Bonding at junctions: toothed bond preferred to straight joint; provide 1/4 brick toothing or use butterfly wall ties for later extensions.

Plastering sequence: clean and wet the surface, apply mortar from bottom to top, level with a float, cure for 7 days, then apply finish coat.

Thistle/gypsum plaster: applied 2–3 mm thick; sets in 20–30 minutes; no curing needed; used for smooth internal finish over brick or block.

External texture finishes: roughcast, pebbledash, tyrolean; improve weather resistance and hide surface defects.

Skirting and dado: skirting height 100–150 mm; dado height 1.2 m in bathrooms and kitchens; use tiles or cement plaster with waterproof additive.

Tile fixing: cement mortar 1:3 with waterproof adhesive; 2–3 mm joints; ensure 90% coverage; cure 24 h before grouting.

Ceiling plaster: 6 mm thick 1:3 mortar; apply from a working platform; check level with a string line before finishing.

Crack repair in plaster: cut out 100 mm wide strip, clean, apply bonding agent, fill with 1:3 mortar and finish flush with surrounding surface.

Water closet types: Indian (squatting) pan with 50 mm trap; European (sitting) with 75 mm trap; flushing cistern capacity 10–15 litres; dual flush 3/6 litres.

Wash basin and sink waste pipe: 32–40 mm diameter with 40 mm trap; floor trap 100 mm with 50 mm seal; gully trap 100 mm with 75 mm seal.

Water tank position: overhead tank at least 1 m above the highest fixture; underground tank at least 1 m away from soak pit and 15 m from septic tank.

Septic tank: capacity 1.5 m³ for 5 users; retention time 24 h; soak pit or drain field for effluent; desludge every 2–3 years.

Rainwater harvesting: roof area × rainfall × runoff coefficient (0.85 for concrete roof) = harvestable volume; first flush diverted.

Pipe slope in drainage: minimum 1:100 for 75 mm pipe, 1:60 for 100 mm, 1:80 for 150 mm; check with spirit level and line.

Backflow prevention: non-return valve on water supply line; air gap between tap and fixture rim at least 25 mm.

Wiring systems: cleat (temporary), casing-capping (surface), conduit (concealed), batten (wooden batten), and CTS (cabtyre sheathed) for industrial use.

Main distribution board: incoming main switch, RCCB, MCB distribution board; label all circuits; keep single-line diagram inside the DB door.

Cable size selection: 1.0 mm² for lighting, 1.5 mm² for sockets, 2.5 mm² for power, 4.0 mm² for AC and geyser; voltage drop not more than 3% of supply voltage.

Lighting levels: 100 lux for corridors, 200 lux for living rooms, 300 lux for kitchens, 500 lux for study areas; use LED to save energy.

Fire safety electrical: use fire-resistant cable for emergency lighting; keep 1 m clearance around electrical panels; no storage under stairs near DB.

Lightning protection: air termination rods on roof, down conductor of 25 × 3 mm copper strip, earth electrode resistance < 10 ohm; test annually before monsoon.

Portable appliance safety: use 3-pin plugs, never bypass earth; check insulation resistance with megger (minimum 1 MΩ at 500 V).

Wood species: teak (durable, expensive), sal (strong, used in doors), deodar (light, used in joinery), plywood and MDF for economical work.

Plywood grades: MR (moisture resistant), BWR (boiling water resistant), BWP (boiling water proof); use BWP for kitchen and bathroom.

Door hardware: hinges 100 mm butt hinges (3 per door); mortise lock at 1 m height; tower bolt at 1.2 m; door stopper at 200 mm from floor.

Window types: casement (side hung), sliding, pivot, louvred, fixed; casement with 4 mm glass; putty bedding 3 mm all round.

Aluminium windows: 1.2–1.5 mm section thickness; EPDM gaskets; drain holes in bottom track; powder coating 50–60 microns.

Furniture joints: dowel and cam-lock for modular furniture; biscuits for panel joints; pocket screws for quick assembly.

Termite treatment: apply chlorpyrifos emulsion to soil before flooring; treat wood with boric acid; keep wood 150 mm above ground.

Paint ingredients: pigment (colour and opacity), binder/vehicle (film former), solvent/thinner (flow), and additives (driers, anti-skinning agents).

Types of paint: distemper (water), emulsion (water, washable), enamel (oil/solvent), lacquer (quick drying), epoxy (chemical resistant), polyurethane (hard).

Primer types: wood primer (alkyd), metal primer (red oxide or zinc chromate), wall primer (alkali resistant), and cement paint primer.

Putty application: 1–2 mm thick on plaster to fill pores; sand after drying; use exterior putty for external walls.

Painting on new plaster: allow 6–12 months drying before oil paint; use emulsion or cement paint earlier; moisture content below 12%.

Spray painting: HVLP or airless; mask surrounding areas; maintain 200–300 mm gun distance; thin paint as per manufacturer's data sheet.

Safety: paints and thinners are flammable; store away from heat; use respirator with organic vapour cartridge; keep fire extinguisher nearby.

Preventive maintenance: periodic inspection of roof, drains, plumbing, electrical and structure; maintain a building maintenance register and log all defects.

Leakage detection: check terrace outlets, pipe joints, wet areas; use moisture meter; trace by observing damp patches after rain or water use.

Repair of plaster and paint: remove loose material, apply primer, fill with putty, sand, and repaint; match colour to adjacent surface.

Epoxy injection for cracks: drill ports at 200–300 mm spacing, seal surface, inject low-viscosity epoxy at low pressure, cure 24 h.

Underpinning: strengthening of existing foundation by widening the footing in sections of 1–1.5 m; use shore and strut to support the structure.

Demolition: obtain permission; use mechanical methods for RCC; protect adjacent structures; dust suppression with water spray.

Renovation of toilets: remove old tiles, redo waterproofing with 2 coats and ponding test for 24 h before tiling.

Approximate estimate methods: plinth area rate (cost per m²), cubical content rate (cost per m³), unit rate, and bay method; used for preliminary budget.

Plinth area estimate: plinth area × plinth area rate; plinth area measured at plinth level excluding open verandahs, balconies and projections.

Detailed estimate: prepare measurement sheet, abstract of cost, bill of quantities (BOQ), and specification; include 3–5% contingency and 1% work-charged establishment.

Labour constants (IS 7272): mason 1 per 1.25 m³ brickwork; carpenter 1 per 10 m² shuttering; painter 1 per 10 m² per coat; unskilled labour 1.5 per mason.

Bar bending schedule: length of bar = clear span + 2 × anchorage – 2 × cover + hooks; cutting length for 90° bend adds 2d, for 135° adds 3d.

Rate of brickwork: number of bricks × rate + mortar volume × rate + labour + scaffolding + profit; add 5% for wastage.

Work measurement: use standard measurement sheet with description, number, length, breadth, depth, quantity; check units and round to two decimals.

Hand tools: trowel, float, plumb bob, spirit level, mason's square, line and pins, bolster, chisel, hammer, saw, plane, measuring tape; inspect handles before use.

Power tools: mixer, vibrator, grinder, drill, cutter; use RCD protection; check cable and plug before use; do not wear loose clothing near rotating parts.

Concrete mixer safety: do not put hands in drum; keep guards in place; switch off before cleaning; place on firm level ground.

Vibration hazard: use anti-vibration gloves; limit exposure to 2–4 hours per day; rotate tasks among workers.

Working at height: use full-body harness anchored to a lifeline; guardrails on scaffolds; do not work in high wind or rain.

Environmental practices: protect trees and topsoil; control runoff with silt fences; reuse excavated soil; avoid burning waste on site.

Emergency response: know the location of first-aid box, fire extinguisher and assembly point; report near-misses; conduct monthly safety drills.

Bricks classification (IS 1077): class A (compressive strength ≥ 10 N/mm²), class B (7.5 N/mm²), class C (5 N/mm²); efflorescence test - no white patches after 7 days.

Sand: pit sand (angular, good for concrete), river sand (fine, good for plaster), sea sand (saline, must be washed before use).

Coarse aggregate should be angular and well graded; flaky and elongated particles reduce strength; limit flaky to 15% for RCC.

Steel reinforcement: Fe415, Fe500, Fe550 with yield strength in N/mm²; Fe415 is common for general RCC; Fe500D has higher ductility.

Concrete cube test: 150 mm cubes, 3 specimens per sample; test at 7 and 28 days; 7-day strength is about 65–70% of 28-day strength.

Bearing capacity of soil: soft clay 50–100 kN/m², loose sand 100–150, stiff clay 150–300, dense sand 300–500 kN/m²; confirm by plate load test.

Brick laying: soak bricks in water for at least 6 hours before use; lay on a full mortar bed; tap with trowel handle to level; check plumb and line every course.

Quetta bond: used for 1½ brick walls with longitudinal cavity filled with concrete; provides reinforcement against earthquake forces.

Rat-trap bond: bricks laid on edge with a 100 mm cavity; uses fewer bricks (about 25% saving) and gives thermal insulation; used for single-storey walls.

Mortar mixing: measure sand and cement by volume; mix dry until uniform colour; add water gradually; use within 30 minutes of mixing.

Curing of masonry: keep wet for 7 days; do not lay masonry in freezing weather; protect from rain and drying wind.

Bonding of new wall to old: rake out old joints to 25 mm, wet, apply mortar, and use toothed bond or wall ties at 450 mm spacing.

Plaster defects: crazing (fine cracks from shrinkage), efflorescence (salt deposits), blistering (air trapped), and patchiness (uneven suction).

Cement plaster on external walls: 1:4 with 15 mm thickness; add waterproofing compound for water tanks and basements.

Lime plaster: 1:2 lime and sand; slow setting, breathable, used in heritage buildings; add 5% cement for faster set.

Gypsum board partitions: 12.5 mm board on 50 mm GI studs at 600 mm centres; joints taped and filled; fire-rated boards available.

False ceiling: gypsum or mineral fibre tiles on GI grid at 600 × 600 mm; keep 300 mm plenum for services; access panels at AC units.

Cornice and mouldings: run with a template on plaster of paris or gypsum; fix with adhesive and screws; sand smooth before painting.

GI pipe sizes: 15 mm (1/2"), 20 mm (3/4"), 25 mm (1"), 32 mm (1¼"), 40 mm (1½"), 50 mm (2"); nominal bore is approximate inside diameter.

PVC pipe classes: SCH 40 and SCH 80 for pressure; SWR (soil, waste, rain) for drainage; use rubber ring or solvent cement joints.

Water pressure: 1 bar = 10 m head = 100 kPa; booster pump required when pressure is below 0.5 bar at the topmost fixture.

Sanitary fittings: wash basin 550 × 400 mm, WC 580 × 440 mm, kitchen sink 600 × 450 mm; fix at 750–800 mm height to rim.

Floor drain: slope floor 1:80 towards drain; provide 50 mm trap; use stainless steel or PVC grating; avoid in shower without slope.

Testing of plumbing: fill pipes with water at 1.5 times working pressure for 2 hours; check joints for leaks; test drainage by smoke or water test.

Circuit protection: MCB for overload and short circuit; RCCB for earth leakage; MCCB for high current; fuse for legacy installations.

Earthing system: TN-S (separate earth), TN-C-S (combined neutral and earth), TT (local earth electrode); use TN-S for new buildings.

Switchboard height: 1.2 m from floor to bottom of board; meter board at 1.5–1.8 m; main switch at 1.5 m.

Lighting control: one-way switch for single point, two-way for staircase, intermediate for long corridors; use 6 A switches for lighting.

Cable routing: avoid sharp bends; keep power and data cables 300 mm apart; do not run cables in wet areas without conduit.

Energy efficiency: use BEE 5-star appliances; LED lamps save 50–80% energy; solar water heater and rooftop PV reduce grid load.

Door types: flush, panelled, glazed, louvred, sliding, folding, revolving; fire doors rated 30/60/120 minutes.

Door frame fixing: holdfasts embedded in masonry at 6 points; gap between frame and wall filled with mortar or PU foam; seal with architrave.

Window glazing: 4 mm plain glass for small panes, 5–6 mm for larger; use glazing putty or EPDM gasket; leave 2 mm clearance for expansion.

Wood finishes: melamine (economical, hard), PU (durable, glossy), lacquer (fast drying), wax (natural look); sand with 180 then 320 grit.

Staircase carpentry: tread 250–300 mm, riser 150–190 mm; handrail height 900 mm; baluster spacing not more than 100 mm.

Termite control: use treated wood, keep wood away from soil, provide ventilation under floors, and apply anti-termite chemical to soil.

Paint calculation: area / coverage per litre = litres per coat; multiply by number of coats; add 10% wastage; 1 litre = 0.26 US gallon.

Enamel paint: alkyd resin base; dries in 6–8 hours; recoat after 16–24 hours; use thinner 10% maximum.

Emulsion paint: acrylic or vinyl; dries in 1–2 hours; recoat after 4 hours; clean with water; low VOC.

Cement paint: two coats on external walls; cure by spraying water after 24 hours; do not apply in direct sun or rain.

Anti-corrosive paint for steel: zinc-rich primer + epoxy intermediate + polyurethane topcoat; total DFT 200–250 microns.

Fire-retardant paint: intumescent coating for structural steel; thickness as per fire rating; apply on clean, primed surface.

Building condition survey: record cracks, dampness, spalling, settlement, and service defects; use a checklist and photographs; prioritise structural safety.

Dampness treatment: identify source (roof, pipe, ground); provide DPC, waterproof plaster, and ventilation; use drainage and sump pumps for basements.

Repair of RCC columns: remove loose concrete, treat steel with rust converter, apply epoxy bonding agent, and jacketing with 75 mm concrete.

Repair of masonry walls: replace damaged bricks, fill joints with 1:3 mortar, provide mesh at junctions, and apply plaster after curing.

Renovation of roofs: remove old waterproofing, clean surface, apply primer, then 2 coats of polyurethane or APP membrane with protection layer.

Post-repair testing: water ponding for 24 h on wet areas, smoke test for drainage, and megger test for electrical insulation.

Cost of construction: material 60–65%, labour 20–25%, plant and machinery 5–10%, overheads and profit 10–15%; varies with location and type.

Contingency: 3–5% for detailed estimate, 5–10% for approximate estimate; include price escalation for projects over 1 year.

Bill of quantities: item description, unit, quantity, rate, amount; measured as per IS 1200; check for omissions and duplication.

Rate analysis of concrete: cement bags × rate + sand m³ × rate + aggregate m³ × rate + labour + mixer + vibrator + profit; per m³ of concrete.

Work measurement units: brickwork m³, plaster m², painting m², flooring m², steel kg, pipes running metre, wiring running metre, fixtures number.

Escalation formula: cost adjustment = base cost × (current index – base index) / base index; use CPWD or state PWD cost index.

Personal protective equipment: safety helmet (IS 2925), safety shoes (IS 15298), gloves, goggles, ear plugs, dust mask, and harness (IS 3521).

Scaffold types: putlog, independent, mobile, suspended; independent scaffold has two rows of standards; putlog scaffold uses the wall for support.

Ladder types: straight, extension, step, platform; aluminium ladders for electrical work; wooden ladders treated with preservative.

Excavation and trenching: use shoring, benching, or sloping; keep heavy equipment away from edge; provide access ladder every 7.5 m.

Concrete pump safety: secure pipeline, use safety pins on couplings, never open pipeline under pressure; stand clear of hose end.

Environmental management: obtain consent to operate; monitor air and noise; manage spoil and debris; protect water bodies from runoff.

Cement types: OPC (general), PPC (fly ash blended, lower heat), PSC (slag, sulphate resistant), rapid hardening, low heat, and white cement.

Cement test: soundness by Le Chatelier apparatus (expansion ≤ 10 mm); fineness by Blaine air permeability (specific surface 225–400 m²/kg).

Concrete grades: M20 for RCC slabs and beams, M25 for columns and water tanks, M30 and above for high-rise and bridges.

Workability tests: slump, compaction factor, Vee-Bee consistometer; compaction factor 0.8–0.92 for normal RCC.

Curing methods: ponding, sprinkling, wet covering, steam curing, and curing compounds; curing improves strength and durability.

Construction sequence: setting out → excavation → foundation → plinth → superstructure → roof → finishes → services → handover.

Brick masonry tools: trowel, mason's square, plumb bob, spirit level, line and pins, bolster, club hammer, jointer, and brush.

Brick bonding at corners: provide queen closer next to quoin header; alternate courses; keep vertical joints 10 mm and staggered.

Hollow concrete blocks: 400 × 200 × 100/150/200 mm; compressive strength 3.5–7 N/mm²; used for partition and load-bearing walls with reinforcement.

Stone masonry types: rubble (random, coursed, dry), ashlar (rough, fine, chamfered), and polygonal; ashlar is strongest and most expensive.

Mortar for stone masonry: 1:4 to 1:6 cement sand; use rich mortar for facing and lean mortar for hearting.

Quality checks: plumb, level, line, joint thickness, bond pattern, and curing; reject cracked or overburnt bricks.

Plastering tools: trowel, float (wooden and steel), hawk, plumb bob, spirit level, screed, corner tool, and brush.

Thickness measurement: use a depth gauge or measure at a cut edge; check with a straight edge and feeler gauge; tolerance ±3 mm.

Plaster mix proportion: 1:3 for external, 1:4 for internal, 1:6 for ceiling; add lime putty for workability in lime plaster.

Bonding agents: PVA or acrylic emulsion applied to smooth concrete before plaster; improves adhesion and prevents debonding.

Waterproof plaster: 1:3 mortar with 1% waterproofing compound; used for water tanks, basements, and external walls.

Texture finishes: sponge finish, broom finish, scrapped finish, and sand-faced finish; choose based on exposure and aesthetics.

Water supply system: overhead tank, down pipes, distribution pipes, and fixtures; use 25 mm main and 15–20 mm branches.

Pipe materials: GI (galvanised iron), CI (cast iron), PVC, CPVC, PPR, copper, and HDPE; choose based on pressure and temperature.

Plumbing fixtures: water closet, wash basin, sink, bathtub, shower, urinal, and floor drain; fix with brackets and sealant.

Drainage system: soil pipe, waste pipe, vent pipe, gully trap, inspection chamber, manhole, and septic tank.

Manhole: 600 × 600 mm inside for depth up to 1 m; 900 × 900 mm for deeper; provide steps at 300 mm spacing.

Septic tank: two compartments; first 2/3 for digestion, second 1/3 for settling; outlet to soak pit or drain field.

Wiring accessories: switches, sockets, regulators, fan hooks, ceiling roses, and junction boxes; use modular plates for neat finish.

Conduit sizes: 20 mm for lighting, 25 mm for power, 32 mm for main; fill not more than 40% of conduit area.

Earthing electrode: copper plate 600 × 600 × 3 mm or GI pipe 38 mm × 4.5 m; backfill with charcoal and salt; maintain water level.

Electrical safety: use insulated tools, rubber gloves, and test lamps; never work on live circuits; lock the main switch before maintenance.

Fire safety: use fire-rated cables for emergency circuits; provide MCB and RCCB; keep extinguishers near DB and kitchen.

Solar PV: rooftop panels, inverter, and net meter; size as per load; clean panels monthly; check earthing and connections.

Carpentry tools: saw, plane, chisel, mallet, hammer, screwdriver, measuring tape, square, marking gauge, and drill.

Wood defects: knots, shakes, warping, twisting, and decay; select straight-grained, seasoned wood free from defects for joinery.

Joinery details: mortise and tenon, dovetail, dowel, biscuit, and pocket screw; use glue (PVA or PU) with mechanical fixing.

Door installation: frame plumb and level; gap 2–3 mm at edges; hinges at 150 mm from top and bottom; lock at 1 m height.

Window installation: frame fixed with screws and sealant; check opening and closing; provide drainage holes in sliding tracks.

Modular furniture: 18 mm plywood or particle board; edge banding 2 mm; use cam locks and dowels; fix with adjustable legs.

Surface preparation for wood: sand with 80, 120, 180 grit; fill cracks with putty; apply primer; sand lightly before paint.

Surface preparation for steel: remove rust by wire brush or sand blasting; apply primer within 4 hours; use zinc-rich primer for structural steel.

Surface preparation for plaster: remove loose particles; apply alkali-resistant primer; fill with putty; sand smooth before paint.

Paint application methods: brush, roller, spray; brush for edges and small areas; roller for large flat areas; spray for uniform finish.

Drying time: primer 4–6 h, undercoat 6–8 h, enamel 16–24 h, emulsion 4 h; recoat only after full drying.

Paint storage: keep in cool, dry, ventilated area; close lids tightly; store away from fire; use within shelf life (1–2 years).

Maintenance types: preventive (scheduled), corrective (after defect), and emergency (urgent); prepare annual maintenance plan and budget.

Inspection checklist: roof, rainwater pipes, drains, walls, plaster, paint, doors, windows, plumbing, electrical, and fire safety.

Crack repair materials: epoxy injection, cement grout, polymer mortar, and non-shrink grout; choose based on crack width and cause.

Waterproofing repair: remove old layer, clean, apply primer, then 2 coats of PU or cementitious coating; protect with screed.

Renovation of electrical: replace old wiring with copper, provide RCCB, earthing, and separate circuits; test insulation resistance.

Renovation of plumbing: replace old GI pipes with CPVC or PPR; provide new traps and vents; test for leaks before closing.

Estimate types: approximate, detailed, revised, and supplementary; detailed estimate is based on drawings, specifications, and rates.

Measurement sheet: item number, description, number, length, breadth, depth, quantity; use standard units and round off correctly.

Abstract of cost: item, quantity, unit, rate, amount; total cost; add contingency, work-charged establishment, and GST.

Rate analysis of brickwork: bricks, mortar, labour, scaffolding, and profit; per m³; use current market rates.

Rate analysis of plaster: mortar volume, cement, sand, labour, curing, and profit; per m²; add 10% for wastage.

Cost control: compare actual vs budget; monitor material wastage; use bar chart or CPM for scheduling; update rates periodically.

Safety signs: mandatory (blue), prohibition (red), warning (yellow), and safe condition (green); display at site entrance and work areas.

Fire safety: keep extinguishers (ABC dry powder, CO2) at site; no open burning; store flammable materials separately; provide escape routes.

First aid: keep box with antiseptic, bandages, cotton, scissors, and pain relief; train at least one worker per 50 in first aid.

Tool maintenance: clean and oil hand tools; check power tool cables; replace worn bits and blades; store in a dry place.

Waste segregation: concrete and brick rubble, wood, metal, plastic, and hazardous waste; reuse rubble for filling; recycle metal and plastic.

Environmental protection: control dust with water spray; prevent soil erosion with silt fences; protect trees; dispose waste at authorised sites.

Concrete mix design: target mean strength = characteristic strength + 1.65 × standard deviation; use IS 10262 for mix design.

Durability: minimum cement content 300 kg/m³ for RCC; maximum water-cement ratio 0.50; cover 40 mm for columns, 20 mm for slabs.

Shuttering removal: vertical sides after 24 h; soffit of slab after 7 days (up to 4.5 m span); beams after 14 days; props after 21 days.

Brick masonry strength: depends on brick strength, mortar strength, and workmanship; use 1:6 mortar for load-bearing walls.

Damp proofing: provide DPC at plinth, waterproofing on roof and wet areas, and ventilation to control dampness.

Construction joints: provide at 1/3 span for beams; roughen surface, clean, and apply bonding agent before concreting.

Brick masonry bonds: English, Flemish, stretcher, header, rat-trap, and Quetta; choose based on wall thickness and strength requirement.

Header course: bricks laid with their length perpendicular to the wall face; used in English bond to tie the wall.

Stretcher course: bricks laid with their length parallel to the wall face; used in stretcher bond and as facing in English bond.

Closer: a brick cut to make the bond; queen closer (half brick lengthwise), king closer (three-quarter brick), and beveled closer.

Brick masonry curing: keep wet for 7 days; protect from rain and sun; do not disturb until mortar sets.

Quality control: check brick strength, water absorption, efflorescence; test mortar strength; check plumb and level.

Plastering defects: cracks, blistering, efflorescence, and debonding; causes include poor surface preparation, wrong mix, and rapid drying.

Crack repair in plaster: cut V-groove, clean, apply bonding agent, fill with 1:3 mortar, and finish flush with surrounding surface.

Efflorescence removal: brush dry, wash with water, and apply alkali-resistant primer; prevent by using low-salt materials and DPC.

Blistering repair: remove affected area, identify moisture source, dry, apply primer, and replaster with waterproof mortar.

Debonding repair: remove loose plaster, apply bonding agent, and replaster with 1:3 mortar; check hollow sound by tapping.

Finishing coats: putty, primer, paint, or tiles; choose based on location, moisture, and maintenance requirement.

Water supply layout: overhead tank, main down pipe, distribution branches, and fixtures; use 25 mm main and 15 mm branches.

Pipe sizing: 15 mm for single tap, 20 mm for bathroom, 25 mm for kitchen and washing machine, 32 mm for main.

Drainage layout: soil pipe, waste pipe, vent pipe, gully trap, inspection chamber, and manhole; slope 1:60 to 1:80.

Trap types: P-trap, S-trap, Q-trap, gully trap, and floor trap; seal depth 50–75 mm; prevent sewer gas entry.

Ventilation: provide vent pipe at the top of the drainage stack; extend 150 mm above roof; keep away from windows.

Testing: water test for supply pipes at 1.5 times working pressure; smoke test for drainage; check for leaks and blockages.

Wiring layout: main switch, DB, sub-circuits, switches, sockets, and light points; keep power and lighting circuits separate.

Cable selection: 1.0 mm² lighting, 1.5 mm² sockets, 2.5 mm² power, 4.0 mm² AC; check voltage drop and current capacity.

Earthing: provide earth electrode, earth wire, and earth pit; test resistance with earth tester; maintain below 1 ohm.

Safety devices: MCB for overload, RCCB for leakage, and SPD for surge; test RCCB monthly; replace faulty devices.

Lighting design: use lumen method; lux = lumens × utilization factor × maintenance factor / area; choose LED for efficiency.

Energy audit: measure load, identify inefficient equipment, and replace with energy-efficient alternatives; monitor monthly consumption.

Wood selection: teak, sal, deodar, pine, and plywood; choose based on strength, durability, and cost; use seasoned wood.

Seasoning: air seasoning for 6–12 months; kiln seasoning for 7–14 days; moisture content 10–12% for joinery.

Wood preservation: apply preservative by brushing, dipping, or pressure treatment; use CCA or boric acid for internal wood.

Door types: flush, panelled, glazed, louvred, sliding, folding, and fire doors; choose based on function and fire rating.

Window types: casement, sliding, pivot, louvred, and fixed; choose based on ventilation and space.

Hardware: hinges, locks, handles, tower bolts, door closers, and stoppers; use good quality hardware for durability.

Paint types: distemper, emulsion, enamel, lacquer, epoxy, and polyurethane; choose based on surface and exposure.

Primer: wood primer, metal primer, and wall primer; apply before paint to improve adhesion and prevent corrosion.

Putty: fill cracks and pores; use exterior putty for external walls; sand smooth before paint.

Paint application: brush, roller, or spray; use appropriate method for surface and finish; maintain uniform thickness.

Drying and recoating: follow manufacturer's instructions; do not recoat before full drying; sand lightly between coats.

Safety: use PPE, ensure ventilation, store paint away from fire, and dispose empty containers properly.

Maintenance plan: prepare annual schedule; inspect roof, drains, plumbing, electrical, and structure; record defects and actions.

Crack repair: use epoxy injection for fine cracks, cement grout for medium, and polymer mortar for wide cracks; cure properly.

Waterproofing repair: remove old layer, clean, apply primer, and apply 2 coats of PU or cementitious coating; protect with screed.

Concrete repair: remove loose concrete, clean steel, apply rust converter, bonding agent, and polymer-modified mortar.

Renovation: obtain structural clearance, plan sequence, protect adjacent areas, and test services after completion.

Post-repair inspection: check for leaks, cracks, and finish; test electrical and plumbing; record in maintenance register.

Estimate preparation: study drawings, prepare measurement sheet, abstract of cost, and BOQ; use current rates and specifications.

Measurement rules: use IS 1200; measure brickwork in m³, plaster in m², painting in m², steel in kg, and fixtures in number.

Rate analysis: calculate material, labour, plant, overheads, and profit; use labour constants from IS 7272.

Cost control: monitor actual vs budget; control wastage; use scheduling and progress reports; update rates periodically.

BOQ: item description, unit, quantity, rate, and amount; check for omissions and duplication; include contingency.

Escalation: use cost index; calculate adjustment as per formula; include in contract for long-duration projects.

Safety policy: prepare site safety plan; conduct induction training; provide PPE; display safety signs; report accidents.

Scaffolding: use independent or putlog scaffold; provide guardrails, toe boards, and access ladders; inspect before use.

Excavation: provide shoring, benching, or sloping; keep spoil away from edge; test for gas; provide access ladder.

Electrical safety: use RCCB, earth all equipment, lockout-tagout, and use insulated tools; never work on live circuits.

Environmental practices: control dust, noise, and waste; protect trees and water bodies; dispose waste at authorised sites.

Emergency response: provide first aid, fire extinguishers, and assembly point; conduct drills; report near-misses.