Fill Identification Supervision Gaps in Borama: How Do Weak Checks Cause Uneven Settlement?

Fill identification supervision gaps in Borama appear when the material placed under a building pad is accepted on the contractor's word rather than on a record the client or their representative can inspect. The gap is procedural, not technical: the contractor decides what is fill, the supervisor is not on site at delivery, and no test result or batch log exists when the layer is compacted. The material then sits under the slab as an unverified assumption. Settlement under the slab, cracked block walls and doors that no longer close are the usual result.

Borama sits in a hot, dry inland climate with a bimodal rain pattern, the Gu and Deyr rains, and the surrounding terrain mixes residual soils, seasonal watercourses and shallow weathered rock. That variety makes fill identification on every plot a fresh decision rather than a rule copied from the last job. A supervisor who checks only the finished level has no idea what those last 300 mm contain.

What does fill identification actually mean on a Borama building site?

Fill identification is the process of testing and classifying material before it is placed as fill, then deciding where that material may be used. On a Borama plot the question is practical: is this imported gravel, this cut material from the plot, or this borrow pit soil good enough to sit under a floor slab or a strip footing, and at what thickness and moisture content?

Three properties decide most cases.

• Particle size distribution. A fill with too many fines holds water, softens after rain and compresses under load. A fill with too much coarse gravel and no binder drains but compacts poorly unless it is graded.
• Fines and plasticity. Clay and silt lumps survive spreading and compacting as pockets. When they later shrink or soften, the surface above them drops.
• Organic content and rubbish. Roots, topsoil, animal waste, plastic and construction debris compress, rot and leave voids. No amount of compaction fixes them.

In Somaliland practice, fill on many plots is whatever the nearest truck can deliver, mixed with material cut from the excavation. That is workable if someone tests it. The failure mode in the brief is not that bad fill exists; it is that nobody records what was delivered, so no one can accept or reject it. A supervisor cannot reject a load that has already been spread and mixed into the pad.

If you want to know how fill is handled on sites near you, ask the Borama municipal engineer's office which fill sources are licensed in the district and which local plots have used them, then walk a plot that is currently importing fill and watch the delivery.

Where do supervision gaps open the door to bad fill in Borama?

Supervision gaps open at four points, and each one is a moment when a decision is made without evidence. The first is the borrow source. Someone agrees on a truck or a pit by phone. No one visits the pit, digs a trial hole or looks at the face. The second is delivery. Trucks arrive when the supervisor is absent, or after the day's concrete work has taken attention. The third is spreading. Loads from different sources are mixed because it is easier to push them out together. The fourth is acceptance. The layer is signed off in a diary entry such as "fill compacted", with no batch number, no moisture reading and no test.

Absentee supervision is the norm on smaller private builds in Borama because owners hire a supervisor part-time, often for the structural frame only. The fill phase is treated as preparation, not structure, and therefore as low-skill work. The result is that the least supervised part of the job is the part that determines how the floor behaves for the next thirty years.

There is a cost dimension too. When a contractor prices a job to win it, fill testing, trial holes at the borrow pit and a water bowser for moisture control look like removable overheads. Removing them shifts the risk to the client. The brief for this article describes the mechanism: weak supervision lets that shift go unnoticed until settlement appears.

How does unsupervised fill turn into uneven settlement?

Unsupervised fill turns into uneven settlement because the pad never becomes one material. Instead it becomes a patchwork of loads with different fines content, different moisture and different compaction. Under a slab, water from washing, leaks and the Gu and Deyr rains moves through the coarser patches and stalls in the clay pockets. The clay swells, then dries and shrinks, then compresses when loaded. The slab above follows the patch beneath it.

A useful way to picture it is a strip footing that crosses three zones: imported gravel at one end, cut silty soil in the middle, rubbish-filled ground at the other. All three may pass a visual check on the day they are placed. After one wet season and one dry season they behave differently. Cracks appear along the boundary between zones, and door frames near the middle stop closing because the floor has dropped a few millimetres more than the walls behind it.

This is why settlement is often reported late. Nothing looks wrong at handover. The building tells you during the first year of weather.

The mechanism also explains why "compact it harder" is not a fix. A compactor cannot make a clay lump into gravel. It can only press whatever is under the drum. If the material is wrong, effort is wasted on the wrong target.

What can a supervisor or client check on site without a laboratory?

A supervisor or client can catch most bad fill on site with a delivery log, a jar test, a moisture squeeze and a level check, all of which need only a few minutes per load. Test records from an approved laboratory are better, but the point-of-delivery checks are what stop a bad load entering the pad at all.

Use this sequence:

1. Log every truck before tipping. Record the date, the source pit, the approximate volume and a sample photo. If the source changes, the log must show it.
2. Run a jar shake test. Fill a clear jar one third with soil, top up with water, shake and let it settle. Sand drops first, silt next, clay stays cloudy longest. A layer that stays cloudy for hours is telling you the fill will hold water.
3. Squeeze a moist sample. Material that forms a ribbon you can bend without breaking carries a lot of clay. Material that crumbles is sandier. Both can be acceptable, but you should know which you have.
4. Look for the obvious rejects. Roots, dark topsoil, animal waste, plastic, plaster offcuts and soft clay lumps are reasons to stop the load and send it back.
5. Spot-check levels against the drawings. A dumpy level or a rotating laser will show whether the layer is even. Fill placed in thin, uniform layers compacts better than fill pushed into mounds.
6. Record moisture and compaction in the daily log. For most granular fill, water should be added until a squeezed ball holds together without dripping, then compacted. The exact target moisture comes from the test result for that material; do not guess.

Where the design includes a slab or footing, ask for the fill acceptance record: source, batch, test result, layer thickness, moisture and compaction method. If the contractor cannot produce it, the layer is unverified, whatever the surface looks like.

How should fill acceptance and rejection work on a Borama contract?

Fill acceptance should be a written decision with a named person, a defined sampling frequency and a defined consequence for rejection, agreed before the first truck arrives. Without that, acceptance defaults to whoever is standing there, and rejection becomes an argument about money.

A workable clause set for a private Borama build:

• The contractor names the fill source and gets it approved by the client's supervisor before import begins.
• One sample per source is tested for grading, plasticity and organic content before the source is used. The cost of that test sits in the contractor's price, not as a later extra.
• Every delivery is logged and checked at the gate. Rejected loads leave the site.
• Fill is placed in layers, each layer compacted and accepted before the next is tipped.
• The supervisor signs each layer on the same day. Unsigned layers are not covered.

Note what this does to incentives. If a rejected load costs the contractor the trucking, the contractor starts caring about the source. If rejection only costs a diary entry, the cheapest material wins every time.

For public or larger projects, check whether the client's engineer has a specification for structural fill and a sampling frequency. If none exists, ask for one in writing before work starts. The Borama municipal engineer's office and the client's consulting engineer can tell you which test houses in the region are accepted for these tests; ask them directly rather than relying on a contractor's recommendation.

Why does splitting supervision duties make the gap worse?

Splitting supervision duties makes the gap worse because fill decisions fall between roles. The structural supervisor watches concrete, the clerk of works watches materials on paper, the contractor's foreman watches the programme, and the owner watches the budget. Nobody owns the fill.

On many Somaliland sites the roles are not even separate people. The same foreman may order fill, place it and record it as accepted. That is not a moral failure; it is a design failure in the supervision arrangement. A person cannot check their own work and produce independent evidence.

A simple separation closes most of it: the person who orders the fill does not sign the acceptance, and the client or their representative signs the layer record. On a small build, the client can do this themselves with a daily walk at tipping time. Fifteen minutes at the right hour beats a full day of looking at a finished surface.

Another split worth closing is between the fill and the drainage. In Borama, plot levels and surface drainage around the building decide how much water reaches the fill. If the supervisor only checks fill and ignores the fall of the surrounding ground, the best fill in the district can still be soaked every Gu. Ask who is responsible for finished levels around the building, and write the answer into the same acceptance record.

What to do next

Before your next fill delivery in Borama, write a one-page fill acceptance sheet and take it to the site. List the source pit, the delivery date, the truck, the layer number, the moisture check, the level check and a signature line for the person who is not ordering the fill. Add the jar test result for the first load of each source. Give a copy to the contractor and keep the original. If the contractor cannot name the source pit or refuses the sheet, treat that as the first rejection and do not tip. Then visit the pit yourself or send someone who can photograph the face and the stockpile. When you have the first signed records in hand, ask the client's engineer to confirm the layer thickness and sampling rate for the rest of the job, and hold the first payment against the signed sheets rather than against the programme.