How do you check site numeracy on a Garowe build?

Site numeracy supervision gaps in Garowe show up when nobody on site re-measures the work. A figure copied from a drawing to a delivery note to a bill of quantities, without anyone checking it against what is actually built, lets a quantity error pass into concrete, blockwork or backfill. The mistake is cheap to fix while it is exposed and expensive once it is covered.

What does weak site numeracy actually look like?

It looks like a wall built to the wrong setting-out line, a floor slab that runs out of level across the room, or a delivery of blocks signed for without a count. A supervisor with weak numeracy can read a drawing but may not reconcile it against the ground. The gap widens when the same person checks a bar bending schedule against a cutting list without re-measuring the bars. Heat, dust and glare on a dry inland site can shorten the time anyone spends checking, so ask what time of day the setting-out was done.

Where do measurement and quantity errors do the most damage?

They do the most damage where the next trade covers the work. Foundation depth and width, reinforcement spacing, slab thickness and floor level all disappear under concrete, blockwork or screed. If the supervisor accepts the subcontractor's figure rather than measuring, the defect is sealed in. The same applies to quantities: a block count that does not match the wall area means either a short delivery or an over-claim, and both get discovered late. The general practice is to record measurements before covering and retain the record. Confirm the project specification and the engineer's requirements for hold points, and ask the permitting engineer or project engineer what evidence is required before covering work.

How do you catch it before the work is covered?

Catch it with a re-measure and a written tally, done by someone other than the person who set the work out. Walk the recent work with the approved drawing, a tape, a level and the delivery notes, and write down what you find. General practice for a pre-cover check is a short sequence of re-measurements and counts, to be confirmed against the project's specification and the engineer's requirements:

• Re-measure the setting-out against the approved drawing, not against the previous day's mark.
• Check floor level and slab thickness at the corners and the middle of each bay.
• Count blocks, bags and bars on arrival against the delivery note, and keep the signed note.
• Photograph the reinforcement and the excavation before concrete or backfill goes in.

What to do next

Pick one recent pour or blockwork lift in Garowe and re-measure it against the approved drawing. Write down every difference and the quantity you expected against what arrived. Then agree with the supervisor and the subcontractor who signs the pre-cover record, and ask the permitting or project engineer what evidence is required before the next stage is covered.