Site Supervision: What to Check, and When It Is Too Late to Check It

Most owners visit their site often. Rather fewer know what they are looking at, which means the visit becomes a walk around a building that is going up, rather than an inspection.

The distinction matters because construction has a property that is easy to forget: most defects become invisible before they become apparent. Steel is checked before concrete or not at all. Waterproofing is inspected before screed or never. Conduits are verified before plaster or discovered with a drill years later.

So here is what to check, arranged by the moment after which it cannot be checked.

Excavation and foundation

• Depth against the drawing, and against the soil report — not against what looks solid.
• Bottom is clean, level and firm. No loose spoil left in the pit.
• Anti-termite treatment applied before the fill goes in.
• Footing size and position against the setting-out. Errors here propagate through the whole building.

Expires at: the first pour.

Before every concrete pour — the single most valuable check

If you do only one thing from this article, do this one. Walk the slab before the concrete arrives.

• Bar diameter. Count and measure. A 12 mm bar substituted for a 16 mm is invisible under concrete and permanent.
• Spacing. Bars at 150 centres versus 200 is a real difference in capacity.
• Cover. Reinforcement must sit clear of the formwork — cover blocks in place, not bars resting on the shuttering. Insufficient cover is the primary cause of corrosion and spalling in Indian concrete a decade later, especially where the surface is exposed.
• Laps and anchorage at the right locations and lengths, not wherever the bar happened to end.
• Formwork props and alignment — properly braced, plumb, and not resting on soft ground.
• Conduits and sleeves cast in where services must pass through, before the pour, not drilled afterwards.

Photograph all of it. Ten minutes with a phone before every pour builds a record that is worth a great deal if a dispute ever arises.

Expires at: the pour. There is no later.

During and after the pour

• Concrete properly compacted with a vibrator, but not over-vibrated to the point of segregation.
• No cold joints — a pour that stops for two hours and resumes creates a plane of weakness.
• Curing. Kept continuously wet for the full period. Concrete gains most of its strength in the first three weeks and only in the presence of water.

Curing is where Indian sites lose the most quality for the least reason. It costs water and someone's attention. It is dropped because the site is in a hurry and because nobody can see the difference until the cracks arrive years later.

• Formwork struck only after the specified period. Early stripping of slab props causes deflection that never recovers.

Masonry

• Bricks or blocks wetted before laying, so they do not draw water out of the mortar.
• Joints fully filled, courses level, walls plumb — check with a spirit level and a plumb bob yourself, at several points.
• Lintels over every opening, with proper bearing at both ends.
• No unfilled gap left where masonry meets the underside of a beam.

Services — the plaster deadline

Everything here is verified before plaster or lives unverified forever:

• Every electrical point present, at the correct position and height, against the drawing.
• Conduits continuous, with draw wires in place, so cables can be pulled and replaced later.
• Plumbing lines pressure-tested before concealment. Insist on this and watch it happen.
• Falls and slopes correct in every wet area — water must run to the drain, and this is checked with a bucket of water, not by eye.
• Waterproofing applied to all wet areas, terraces, balconies and sunken slabs, and ponded for at least 24 hours and inspected for leaks before anything covers it.
• Chases cut cleanly and not through structural members. A conduit chased across a beam or a column is structural damage.

Photograph every wall and every floor before plaster, with something in frame for scale. This single habit is worth more in year ten than everything else on this list.

Expires at: plaster.

Finishes

• Plaster flat, checked with a straightedge, and cured.
• Tile levels, joint alignment, and hollowness — tap the tiles and listen. A hollow sound means poor bedding, and it will crack.
• Slope in bathrooms and balconies verified with actual water.
• Door and window frames plumb, and sealed at the junction with masonry — a common water entry point.
• Paint over a properly prepared and primed surface, not over dust.

The four questions worth asking at every visit

Whatever stage you are at, these four questions extract more than a general look around:

1. What is being covered up this week? That tells you what to inspect now.
2. Which drawing revision are you working from? Superseded drawings on site cause expensive rework.
3. What is waiting on a decision from me? Late owner decisions are the most common cause of delay, and contractors often will not chase you for them.
4. What did not go according to drawing this week, and how was it resolved? Something always deviates. The question is whether it was resolved deliberately or quietly.

An honest note about what this can and cannot do

An owner running these checks catches a great deal — probably most of the visible problems, and some invisible ones. What an owner cannot reasonably do is assess whether the structural design is right for the soil, whether a lap position is acceptable in a particular member, or whether a crack is shrinkage or something worse.

That is the argument for periodic professional inspection at defined stages rather than continuous presence: a qualified visit before each pour, at plaster stage and at handover, will catch the class of problem that experience recognises and a checklist cannot describe.

Between those visits, this list is yours. Keep it in your phone. Take the photographs. Ask the four questions.