A new site engineer's main job is to make sure what gets built matches the approved drawings and specification, safely, and that every quantity and instruction is recorded. In practice that means reading drawings before work starts, checking layout and levels, checking materials and steel before every pour, controlling concrete and curing, and keeping a clean site diary and measurement book.
These tips come from the problems that most often show up on building and road sites in Nepal. They apply whether you work for a contractor, a consultant or a municipality.
1. Read and cross-check the drawings first
- Check the revision number and date on every sheet. Keep only the latest set on site and mark old sheets "superseded".
- Compare architectural and structural drawings: grid spacing, column positions, beam depths under windows, stair openings and floor levels often clash.
- Read the general notes: concrete grade, steel grade, cover, lap length, curing and stripping times are usually written there.
- When something does not match, ask the designer in writing and wait for a written reply. Do not let the mistri guess.
2. Layout and levels
Set out from the grid lines on the drawing, not from a neighbour's wall. Fix profile boards outside the trench line so the strings can be re-fixed after digging.
Worked example, squaring the corners: for a building 12.00 m × 9.50 m, each diagonal should be √(12.00² + 9.50²) = √234.25 = 15.31 m. If the two diagonals differ, one corner is out of square; adjust and measure again. For a single corner, the 3-4-5 rule works: 3 m along one side, 4 m along the other, and the line between those points should be exactly 5 m. Larger multiples such as 6-8-10 are more accurate.
Worked example, plinth level: the benchmark (BM) has RL 100.000 m. Backsight on the BM is 1.450 m, so height of instrument = 100.000 + 1.450 = 101.450 m. For a plinth level of RL 100.750 m, the staff reading at the plinth should be 101.450 − 100.750 = 0.700 m. Mark it on a peg or column and check it again from a second setup. The levelling calculator works out longer level runs by the rise and fall or HI method.
Protect the BM. Fix a temporary benchmark on something that will not move, such as a boundary pillar, and record it in the site diary.
3. Checking materials
- Cement: check the manufacturing date on the bag, reject hard lumps, store on a raised platform away from walls and moisture, and use older stock first.
- Sand: check silt and clay; a simple field silt test in a glass jar of water shows the layer that settles on top. River sand with too much silt weakens plaster and concrete.
- Aggregate: correct size, clean, not too many flat or elongated pieces.
- Bricks: uniform size and colour, a clear ringing sound when two are struck, no deep cracks.
- Steel: grade marked on the bar, mill test certificate, no loose rust, and correct weight.
Steel weight check: weight per metre of a bar = D² / 162 kg, with D in mm. A 16 mm bar should weigh 256 / 162 = 1.58 kg/m, so a 12 m length should be about 18.96 kg. If bars weigh noticeably less, they may be undersize. Check other sizes with the steel weight calculator.
4. Steel and cover before every pour
Check reinforcement against the drawing before you allow concrete: bar size, number, spacing, laps, stirrup spacing and hooks. In earthquake-resistant detailing, stirrups are closer near beam-column joints and have 135 degree hooks, and column laps are kept away from the joint zones. Use cover blocks of mortar or concrete, never stone pieces, and chairs to hold top slab bars.
| Member | Commonly used clear cover | What to check |
|---|---|---|
| Footing | 50 mm | Blocks under bottom mesh, steel not touching soil |
| Column | 40 mm | Bars plumb, ties at correct spacing, laps in the right zone |
| Beam | 25 mm | Side and bottom cover, stirrup spacing near supports |
| Slab | 15 to 20 mm | Chairs for top steel, extra bars at openings |
These are typical values for normal exposure. The drawing and IS 456 or your project specification decide the actual cover, so follow them where they differ.
Also check the formwork: tight joints, enough props on firm base, correct level and camber, and release oil applied before steel is placed.
5. Concreting and curing
- Fix the mix and the amount of water before starting. Extra water added to "make it flow" is the most common cause of weak concrete.
- Do a slump test on the first batches and whenever the mix looks different.
- Vibrate properly, especially at column bases and beam-column joints, without touching the steel for long.
- Cast 150 mm test cubes from the same concrete and test them at 7 and 28 days.
- Stop work only at planned construction joints.
- Cure for at least 7 days for ordinary Portland cement concrete, and longer in hot dry weather or with blended cements, as IS 456 advises.
- Remove props only after the stripping times in the specification.
The concrete calculator gives cement, sand and aggregate quantities for a pour, so you can check that the right amount of cement is actually used.
6. Record keeping: site diary and measurement book
Site diary: write daily: weather, labour and equipment on site, materials received, work done, tests taken, instructions given or received, visitors, and any problem or delay. Short notes written the same day carry weight in later disputes.
Measurement book (MB): the record of measured quantities on which payment is based. Write in ink, date every page, and get the contractor's representative to sign. Measure hidden work before it is covered: foundation depth before backfill, steel before concreting.
Also keep a drawing register, material register, test reports and dated photos of hidden work.
7. Safety on site
- Helmets and proper shoes for everyone; safety harness for work at height.
- Guard rails or covers at slab edges, stair openings and lift shafts.
- Braced and tied scaffolding with full planks.
- Support or slope the sides of deep trenches and keep spoil and materials away from the edge.
- No loose electric cables lying in water; a first aid box on site.
- Keep children and passers-by out, especially on roadside plots in town.
8. Working with contractors and owners
- Be polite and firm. Give instructions clearly, and confirm important ones in writing.
- Do not certify quantities you have not checked.
- When an owner wants a change, explain the effect on structure, cost and permit, and get the designer's approval first.
- Listen to experienced mistri and foremen; many know practical tricks. Verify before you accept.
- Do not accept gifts or favours that could affect your judgement.
Frequently asked questions
What does a site engineer check before a slab pour?
Formwork level and props, steel size and spacing, cover blocks, chairs, conduits and sleeves, cleaning of the formwork, and that materials, vibrator and labour are ready for a continuous pour.
What is a measurement book?
It is the signed record of measured work. Running and final bills are prepared from it, so entries must be accurate, dated and signed.
How do I check if steel bars are underweight?
Weigh a measured length and compare with D² / 162 kg per metre. For 12 mm bars that is about 0.89 kg/m.