How do you check kerb alignment claims in Berbera?

Kerb alignment competency risks in Berbera are evidence gaps. A contractor may set out a line that looks right, yet no level record survives, no offset mark stays in the ground and no one can say what fall the channel has. The client then approves the visible bend instead of the built line, and the roadside drainage that depends on that fall is judged by eye.

This is a risk mechanism, not a claim about any firm. It shows up wherever supervision is thin and records are verbal.

What does poor kerb setting out look like on site?

It looks like a channel that ponds, a kerb face that wanders in plan, and no level book to explain either.

A kerb is set by line and level. The line follows the road edge or the channel edge; the level gives the fall along the channel and, on a flush or drop kerb, the cross fall at crossings and entrances. In general practice, the setting out crew drives pegs at a set spacing, paints or nails an offset mark clear of the works, and takes levels with a dumpy level or a total station against a known benchmark. Those readings are the competency evidence.

Where that evidence is missing, three things follow. First, the channel can pond at low spots. Second, the kerb face can wander in plan, so joints open and the line reads badly from the road. Third, a later trade, a driveway, a drainage connection or a footpath, has no fixed level to work to.

To test the mechanism locally, find out what survey control is available near the road and agree with the contractor and your engineer on the record format for the setting out. If no benchmark can be identified, ask the surveyor to establish one and to hand you the reduced levels.

How do you check a kerb line before you pay?

You check the record, then the built line, then a sample of levels, in that order.

Start with the paperwork supplied at tender or before mobilisation.

• Setting out drawings showing the channel invert levels and the kerb top levels.
• Reduced level sheets from the setting out survey, signed by the person who took the readings.
• The benchmark used and the route run from it to the site.
• Names and roles of the crew: who set out, who checked, who approved.

Then walk a recently completed stretch by the same team, if one exists, and look at the channel after rain or after a water test. Ponded water shows a fall that has gone wrong, whatever the level book says.

Then ask for one bay, or a short trial length agreed with your engineer, cast under your supervision with levels taken before and after. A supervisor can check the formed line with a string and the levels with a level and staff. Ask the contractor to name the tolerance the project specification allows for kerb line and level, and confirm that figure with your engineer before you accept the work.

One test bay, measured and paid, answers the competency question faster than any file of past project lists.

Where does the interrupted roadside drainage risk come from?

It comes from treating the kerb as a finish item rather than as the top of the drainage system.

A roadside channel works when the fall is continuous from high point to outfall, gully or soakaway. If a section is set flat or backfalls, water stops moving and sits. Silt and wind-blown sand then collect in the ponded length, and the next rain carries that material to the low point, so the blockage grows each season.

Ask the contractor for the mix design and the curing regime for the kerb concrete, and confirm both against the project specification before casting starts. The alignment question and the durability question both need written answers.

Interruptions also come from construction sequence. If a crossing, an entrance or a culvert is built later and its level disagrees with the channel, someone has to patch the fall. Ask how the contractor will protect the set-out marks and levels between casting and handover, and who will re-check the channel after any service trench crosses it. Utilities laid after the kerb can lift or drop a length of channel.

On a diaspora-funded job, this is the cheapest control you can buy: one level run, in writing, on a named stretch of kerb.

What to do next

Before you release the road works, send the contractor a short written request: reduced levels for the setting out, the benchmark used, and one paid trial bay of kerb cast under supervision, with levels taken before and after and a water test on the channel. Confirm the tolerance with your engineer before you accept the work.