Why do excavation support bids in Borama look too low?

Excavation support underbidding risks in Borama show up when a bid prices only the digging. The tenderer allows for a machine, a driver and a few days of loose soil, then leaves out shoring, dewatering, backfill compaction and spoil removal. On the day the trench sides move, the money and the programme have already gone.

Why do excavation support bids in Borama look too low?

A low bid often means the tenderer priced a hole in the ground, not a supported excavation. Tender documents that describe the work as "excavate for foundations" invite that reading. There is no line for timber or steel shoring, no line for a pump and standby, no line for importing selected backfill, and no line for carting spoil away.

Depth drives the cost. A shallow strip footing in firm ground may need nothing beyond trimmed sides and a watchman. As depth grows, or where the sides cannot stand at the angle the drawing assumes, support becomes a separate item with its own materials, labour and time. General practice is to shore or batter the sides and to keep people out of unsupported trenches, but the correct method and depth limits come from the project's specification and engineer, not from habit.

A bidder under time pressure also skips the site visit. Without walking the plot, nobody checks for old soakpits, filled ground, buried walls, service lines or a high water table. Ask the municipal engineer's office whether it holds any record of earlier excavation or drainage on the plot, and ask the client for any borehole or trial pit logs from previous work next door.

What work gets left out of a cheap excavation support price?

The omitted items are usually support, water, backfill and disposal. Each one is easy to leave out because the drawing shows a clean rectangle with vertical sides and a dry base.

• Shoring materials and the labour to fix and later strike them.
• Dewatering: pumps, fuel, hose, a standby unit and someone to watch the sump at night.
• Disposal of surplus spoil, including loading and a legal tipping point.
• Imported selected fill and the compaction passes to bring it back to the required density.
• Protection of adjacent walls, fences and services, and any temporary propping.
• Working space for formwork and for people, which widens the cut and adds volume.

A tenderer who omits these items is not necessarily dishonest. The bid may simply follow a scope that never named them. The risk lands on the client when the site conditions force the work anyway.

How do you detect the gap before you award the work?

Compare the priced bill against the drawings item by item. A scope gap shows up as a bill with one large excavation line and nothing beside it for support, water or backfill. Ask the tenderer to price each item separately, in writing, and to state what ground and water conditions the price assumes.

Then check the assumptions. Ask what happens to the price if the sides need shoring, if a pump runs for the whole pour, or if the spoil has to travel further. A tenderer who cannot answer has not thought about it. Walk a recent excavation in Borama with the same contractor, or ask to see one, and look at how the sides were held and where the water went.

For major work, request the method statement with the sequence: how deep each stage goes, where the support sits, how the base is kept dry, and how backfill is placed and compacted. Confirm the acceptance limits against the project's specification or engineer. Check what the contract allows on variations before you sign, so the ground you meet on site can be priced fairly rather than argued about.

What to do next

Ask every tenderer for a priced bill with separate lines for shoring, dewatering, disposal and backfill, plus a written list of ground and water assumptions. Send the same questions to all bidders, compare the answers side by side, and keep the replies with the tender file. Award on the total scope, not the lowest digging rate.