In brief
- A contractor's claim of prop removal experience is not evidence; ask for the striking schedule, concrete test results and a signed approval before props come down.
- Props taken down early load green concrete, and the resulting deflection or cracking may only appear weeks later.
- Walk a recent site the contractor struck and ask the municipal engineer's office what records it holds before you sign the next stage.
Contents
A contractor's word that they have struck props before is not evidence. In Borama, prop removal competency risks stay hidden because the decision point is quick, the paperwork thin and the concrete already poured. Before any prop comes down, ask for the striking schedule, the concrete cube results and a signed load check. If those documents do not exist, the work is being loaded on a guess.
Why does an unverified prop removal claim put the slab at risk?
A claim describes past work, and past work on another site says nothing about the concrete now sitting on this one. Striking time depends on the mix, the cement, the water added on site, the shade and the curing, so a crew that struck a slab in three days somewhere else may be guessing here. Remove props before the concrete reaches the strength the design assumes and the slab carries load it cannot yet take. General practice ties striking to cube strength at the relevant age, not to a calendar, and the project specification or engineer sets the figure. Ask for the test certificate that names the cube, the date and the laboratory.
What does premature structural loading look like, and when does it show?
Premature structural loading shows up as deflection, cracking or a slab that sounds hollow under a hammer, and it may appear weeks after the props are gone. Early loading also comes from the site itself: block stacks, water drums and mortar boards parked on a young slab before striking time, or a prop removed to free a walkway and never replaced. Deflection in a suspended slab can be hard to see until finishes go down, and then tiles crack or doors bind. Rapid moisture loss during curing can leave concrete weaker than the mix design assumed, and the site's exposure and curing method decide how far that applies here, so confirm it for the plot with your engineer. Ask the supervisor to record prop positions, the striking date and the cure method for each pour.
How do you check a contractor's prop removal competency before award?
Ask for records, not assurances. A contractor who has struck props properly holds cube test certificates, a written striking schedule and a signed approval for each pour, and can point to a recent building in Borama where that slab still performs. Visit that building and look at ceilings, tiling and door frames for the signs of a slab that moved. Ask the municipal engineer's office what records it keeps for the plot and whether it requires any submission before striking. Check the method statement names who approves striking, what cube result triggers it and what happens if the result is late. If the contractor cannot produce these, price the risk of an independent cube test and a hold on striking into the contract, and confirm with your engineer what the contract allows before you sign.
What to do next
Collect the striking schedule, cube test certificates and the method statement naming who approves prop removal, and ask for a building the contractor struck recently. Walk it and check the ceilings and tiling. Then ask the municipal engineer's office what records it holds for the plot before you approve the next stage of work.
Frequently asked questions
Can a contractor strike props early if the concrete looks hard?
No. Prop removal should follow the project specification, which normally ties striking to concrete cube strength at the relevant age. Appearance on the surface does not show the strength inside, so ask for the test certificate before anyone touches the props.
What records should I ask for before props come down in Borama?
Ask for the striking schedule, the concrete cube test results, the method statement naming who approves striking, and a signed approval for that pour. If the contractor cannot produce them, hold the striking and arrange an independent cube test with your engineer.
Local reporting: this article is written for building work in Borama and Somaliland. Ground conditions, prices and rules differ between places; confirm the details for your own site.