How To Read A Concrete Frame Programme (And Protect The Pour Cycle)

The Pour Cycle Is The Heartbeat Of The Frame

Every other date in a frame programme hangs off one rhythm: how often the team completes a floor. Call it the pour cycle or the floor-on-floor cycle, it is the heartbeat of the package. If that rhythm is realistic and properly resourced, the frame lands and the trades behind it inherit a programme they can trust. If it is optimistic, everything slips behind it, and the slip compounds the higher the building goes.

So reading a frame programme well starts in one place: stress-test the cycle. A bar chart can make any cycle look achievable because the bars simply repeat. Your job is to ask whether the resources behind each repeat can actually deliver it, floor after floor, in real weather, with real concrete strengths.

What A Realistic Cycle Actually Contains

A single floor cycle is not one task, it is a sequence that has to flow without colliding with itself. Roughly, each floor moves through setting out, erecting columns and walls, striking and re-fixing formwork, fixing the deck and reinforcement, installing any post-tensioning tendons, the pour itself, curing, gaining strength, striking, and back-propping to support the floors above while they cure.

1. Set out and erect vertical elements (columns, walls, core if not jumped separately).
2. Strike and reposition formwork and falsework to the next level.
3. Fix the slab deck, reinforcement and any tendons, plus cast-in items and edge protection.
4. Pour, finish and cure the slab.
5. Monitor early-age strength until striking and back-propping criteria are met.
6. Strike, back-prop, and repeat one level up.

A typical UK in-situ floor cycle for a normal slab runs somewhere around one to two weeks depending on area, complexity and resourcing. The exact number matters far less than whether the contractor can explain how each step in that list fits inside it without two trades needing the same space at the same time.

Check The Crane And Access Strategy First

A pour cycle is only as good as the crane time standing behind it. Cranes land formwork, reinforcement, columns and the concrete skips on a pumpless pour, and a single floor can demand hundreds of lifts. The question to ask is simple: how many cranes, what hook time does each floor consume, and does that fit inside the working day with margin for weather and breakdown?

• How many cranes serve the deck, and what is each one lifting at peak?
• Is concrete placed by pump, by skip, or both, and how does that change the crane demand?
• How is reinforcement and formwork landed and distributed across the floor?
• What happens to the cycle on a windy week when lifting stops?

Striking And Temporary Works: Strength, Not Optimism

Formwork striking and back-propping are governed by the early-age strength of the concrete, full stop. You cannot strike a slab because the programme says it is Tuesday; you strike it because the concrete has reached the strength the temporary works design requires. Push that and you risk excessive deflection, cracking, or in the worst case a collapse during construction.

So two questions matter. How does the contractor confirm strength before striking, by cube results, temperature-matched curing, maturity monitoring, or a combination? And does the temporary works design actually support the cycle they have drawn, including the back-propping needed to carry freshly poured floors through onto floors that have not yet reached full strength? This is exactly where aggressive programmes fail quietly, because the dates look fine until the concrete refuses to cooperate.

On a post-tensioned frame the strength question is sharper still, because stressing is itself gated by early-age strength and the stressing sits on the critical path. A team that stresses routinely plans for this; a team that does not will find the cycle slipping around it.

Weather, Winter And The Things That Erode A Cycle

A cycle drawn in a warm office rarely survives a British winter untouched. Cold weather slows strength gain and pushes back striking. Wind stops lifting. Short daylight shortens the working day. None of these are excuses, but a programme that ignores them is fragile, and the fragility shows up exactly when you can least afford it, high in the building with the whole job stacked behind the frame.

• Does the cycle change between summer and winter, and has the contractor said so?
• Is there a plan for cold-weather concreting, or does the programme assume permanent spring?
• How much float sits between the frame and the first following trade?

Protect The Cycle At Tender, Not On Site

The cheapest way to protect a pour cycle is to interrogate it before you award the package. Once the contractor is on site and the cycle is slipping, your options are expensive and your leverage is gone. Before award, a strong frame contractor will happily walk you through their cycle, their crane numbers, their striking criteria and their temporary works basis. A worrying one will wave the questions away and tell you it will be fine.

That difference in response is itself useful information. Pair this with a proper procurement pass; our 12 questions for vetting a frame subcontractor covers the wider package, and our RC vs PT comparison helps you sanity-check whether the chosen system even suits the building. When you want the package priced by contractors who can defend their cycle, tell us about the scheme.

Frequently Asked Questions