The Complete Guide to Concrete Works, from Formwork and Rebar to Pouring and Curing

What concrete works actually include

Concrete works means building the structural elements that carry a building and transfer its loads down into the soil. On every site this work brings together separate trades that have to move in step. Carpentry builds the formwork that gives each element its shape. Steel fixing places the reinforcement that gives the element tensile strength and keeps it from cracking under load. The concrete itself fills the mould, wraps around the steel and resists compression.

These trades cannot be separated. A formwork that is out of line produces a leaning element no matter how good the concrete is. Reinforcement in the wrong position weakens the element even when the formwork is excellent. Concrete that is not cured properly will crack even if the steel and the carpentry are sound. That is why we treat concrete works as one connected chain managed by one responsible party, rather than a set of separate jobs handed to different crews.

Elements usually covered

• Foundations of all types, including isolated footings, tie beams and raft foundations.
• Columns, concrete walls and retaining walls.
• Slabs, beams and staircases.
• Special elements such as water tanks, manholes and box culverts.

Each of these elements has its own method and details. A tank needs special attention to watertightness. A culvert has to resist moving water and soil pressure. A roof slab needs accurate levels so that rainwater does not collect on it later. Treating them all the same way is one of the quickest routes to problems that only appear after handover.

This type of work serves villas, palaces, residential compounds, commercial centres and infrastructure projects. It can be contracted as labour only or as full supply and execution, depending on what suits the owner. In every case the starting point is the same, namely structural drawings prepared and approved by a qualified structural engineer. Without them, nobody on site can know the correct sizes, reinforcement or concrete grade, and the building is exposed to real risk.

At Yam Integrated Construction (YAMIC) we deliver these elements as part of our concrete works service, with engineering supervision at each stage, from our head office in Riyadh to projects across Saudi Arabia.

Formwork and carpentry for concrete

In concrete works, carpentry has nothing to do with furniture or doors. It means fabricating the moulds that concrete is poured into, then fixing and supporting them until the concrete has hardened. Good formwork gives you an element at the correct size with a clean surface, which reduces plastering and correction work later on. Poor formwork shows up in every trade that follows.

Common formwork types

• Traditional timber formwork, which is flexible, suits varied shapes and works well on medium sized projects.
• Steel formwork, which gives a smoother face and is reused efficiently on projects with many repeated elements.
• Treated plywood panels, used where the surface needs a cleaner appearance.

What separates good formwork from bad

The first test is alignment. Vertical sides must be truly plumb and slab soffits must sit at the required level. The second is tight joints, so that mixing water and fine paste do not leak out and leave voids and rough patches on the concrete face. The third is the strength of the supports. Fresh concrete is heavy and pushes hard against the formwork during pouring and vibration, and weak bracing lets the mould bulge or move.

The formwork should be coated with a suitable release agent before the reinforcement goes in. This makes striking easier and protects the concrete surface from peeling away with the timber. The mould must also be cleaned of sawdust, dust, loose nails and offcuts before pouring, because anything left inside stays in the concrete and weakens it.

When to strike the formwork

The timing for removing formwork is set by the engineer according to the type of element, the weather and the cement used. Striking slab formwork too early is a common mistake that can cause sagging or cracks that are hard to repair. Vertical side forms on columns and walls can often come off sooner, but they still need care so that edges and corners are not chipped.

When you visit the site before a pour, look along the formwork lines, check that props are firm and ask whether the engineer has inspected the moulds. These simple checks tell you a lot about the standard of work you will get in the finished frame.

Reinforcing steel and how it is fixed

Reinforcing steel is what turns plain concrete into reinforced concrete. Concrete on its own is strong in compression and weak in tension. The steel makes up for that weakness and carries the tension and bending forces. That is why the bar diameters, the number of bars and their exact positions inside each element are defined precisely in the structural drawings, and they must not be changed on site without going back to the engineer.

Stages of preparing the steel

1. Receiving the steel on site and confirming it matches the specified grade and is free of flaking rust.
2. Cutting and bending according to the bar bending schedules taken from the drawings.
3. Placing the bars inside the formwork in the correct order, main bars and stirrups alike.
4. Tying the intersections with binding wire so the cage does not shift during the pour.
5. Installing spacers or chairs to guarantee the required concrete cover.

Why concrete cover matters

Concrete cover is the distance between the steel and the outer surface of the concrete. It is what protects the reinforcement from moisture, salts and corrosion. If the cover is less than required, the steel slowly begins to rust, expands and cracks the concrete around it. This is one of the most frequent problems we see in older buildings, and once it starts it is expensive to stop.

So it is not enough for the steel simply to be there. It has to be in the right place and at a consistent distance from the formwork. Lap lengths between bars must be correct, and stirrups must be at the specified spacing, especially where columns meet beams and the steel is most congested.

Inspection before every pour

Before any pour, the engineer inspects the reinforcement and compares it with the drawings item by item. This step must never be skipped, however tight the programme becomes, because once concrete covers the steel it can no longer be seen or corrected. A signed inspection record for each pour is your proof that what is inside the structure is what the designer intended.

As an owner, you do not need to count bars yourself. You do need to know that this inspection happened, who carried it out and where the record is kept.

Choosing the right mix for each element

Concrete is not one material that suits every purpose. Each element in a building works under different conditions and needs a mix designed for it. The structural drawings usually specify the compressive strength required for each element, but other factors also shape the mix, and an owner who understands them knows what is being ordered from the plant and why.

What determines the mix design

• Required compressive strength, set by the structural engineer according to the loads.
• The surrounding environment, since an element buried in salty soil needs a denser mix and a resistant cement.
• Reinforcement density, because elements crowded with steel need smaller aggregate and a more workable consistency so the concrete reaches every corner.
• Placing method, as pumped concrete needs a different consistency from concrete discharged straight from the truck.
• Weather at the time of pouring, which is where admixtures that delay or accelerate setting come in.

The water to cement ratio

This ratio is the most important figure in any mix, even though the owner never sees it. Any water beyond what the cement needs eventually evaporates and leaves pores inside the concrete. Those pores reduce strength and give moisture and salts a path to the steel. That is why the plant designs the mix with a fixed ratio and uses plasticisers when the pour needs a more fluid consistency, rather than adding water.

What to ask your contractor for

Ask for the quotation to state the concrete grade for each element, the cement type and any admixtures. Ask for the delivery ticket of every truck to be kept in the project file, because these tickets are the evidence that what was poured on your site is what was agreed. If the supplying plant changes during the project for any reason, ask for the new mix to be reviewed and approved before it is used on your building.

Chemical admixtures and when they are used

Admixtures are materials added in small quantities to a concrete mix to change how it behaves during pouring or after it hardens. They are not a luxury, and they are not a way to rescue a weak mix. They are tools the engineer selects to solve a specific problem on a specific site. Understanding the main types helps you read a quotation and see why one mix differs from another.

The most common admixtures

• Plasticisers make concrete more workable without extra water. They ease placing around dense reinforcement while protecting strength.
• Retarders slow the start of setting. They are useful in summer and on large pours that take a long time, so that cold joints do not form between layers.
• Accelerators help in cold weather, when concrete is slow to gain strength.
• Waterproofing admixtures reduce the permeability of concrete and are used in tanks, basements and foundations exposed to moisture.
• Chemical resistance improvers are added to elements exposed to soil salts or sewage.

When an admixture becomes necessary

In Riyadh and the central region during summer, retarders and plasticisers are among the most widely used. Heat speeds up setting and makes the mix lose workability on the way from the plant to the site. In coastal cities, waterproofing admixtures and chemical resistance products are common for buried elements. In the southern highlands, winter pours may need an accelerator together with protection from the cold.

Mistakes in handling admixtures

• Adding a product on site without the knowledge of the engineer or the plant.
• Mixing products from different sources that may not be compatible.
• Relying on a waterproofing admixture alone while neglecting vibration and curing.
• Using an admixture to justify adding water or cutting cement content.

The simple rule is that admixtures belong in the mix design from the plant and should appear on the delivery ticket. If a contractor proposes adding something on site, ask for the reason and for the engineer to approve it in writing. The right admixture improves concrete. A random one can quietly damage it, and the effect may only show long after the pour, when it is far harder to deal with.

Ready mix concrete, pouring and vibration

Pouring is the moment when all the earlier preparation comes together. It leaves no room for improvisation, because concrete begins to set once it is mixed and a pour cannot simply be paused halfway through without a plan for where and how to stop.

Ready mix concrete

On most projects we rely on ready mix concrete from reputable plants. It arrives with a mix designed for the required compressive strength and fixed proportions of cement, aggregate, water and admixtures. This keeps one pour consistent with the next, which is very hard to achieve with hand mixing on site.

When each truck arrives, the delivery ticket is checked to confirm the mix matches what was ordered. A slump test is carried out to check the consistency of the concrete, and cube samples are taken so the compressive strength can be tested in a laboratory later.

The correct way to pour

• Place concrete in successive layers rather than in one mass from a great height.
• Do not drop concrete from a height that makes the aggregate separate from the mortar.
• Use a mechanical vibrator to drive out trapped air and fill voids around the steel.
• Do not over vibrate, because excessive vibration separates the components of the mix.
• Never add water to the concrete on site to make it easier to place.

Adding water on site is a serious mistake. It makes the work easier for the crew, but it weakens the concrete and increases cracking and porosity. If a mix is difficult to place, the answer is to coordinate with the plant on suitable admixtures, not to reach for the hose. A good site engineer will refuse a truck rather than accept watered down concrete in a structural element.

Levelling and finishing after the pour

Once the concrete is placed, the surface is levelled and finished to suit the element. A roof slab needs accurate levelling to the specified falls and heights. Ground floors may need a smoother finish depending on what will be laid on top. This stage is short, but it decides how much correction work the finishing trades will face later.

If you are planning a concrete package and would like a written quotation, send us your project details and we will arrange a site inspection and prepare a clear, itemised offer.

Organising pour day and choosing the pump

Pour day is the most sensitive day on any concrete project. Trucks, the pump, the crew and the engineer all come together at the same time, and any gap in the organisation can leave a cold joint or force the team to rush vibration and levelling. That is why pour day is planned before it arrives, not on the day itself.

Before pour day

• Inspect and sign off the steel, formwork and embedded services.
• Calculate the concrete volume accurately with a small margin.
• Book the plant and the pump, and agree the arrival time of the first truck and the interval between trucks.
• Confirm the access route for trucks and the position of the pump.
• Prepare the vibrators, including a standby unit and an independent power source.
• Have curing and covering materials ready before the pour begins.

Choosing the pump

A boom pump suits slabs and open sites, because it reaches distant points quickly. A ground pump with pipelines suits tight sites or areas the boom cannot reach. For villas in crowded neighbourhoods, it is essential to confirm that the street allows the pump outriggers to be extended safely before the pump is booked.

During the pour

The engineer sets the pouring sequence. It usually starts at the far end and works back towards the pump. Beams and slab are placed so that no area is left to stiffen before it joins the concrete next to it. The crew is divided between directing the hose, vibrating, levelling and watching the formwork from below for any leak or movement.

Timing the pour around the weather

In the central region in summer it is better to start in the very early hours so that most of the work is finished before the heat builds. In coastal cities wind and humidity are taken into account. In the south, pouring before a night expected to be very cold is avoided unless there is a clear covering plan.

After the last truck

Final levelling begins, followed immediately by curing. The pump and tools are washed out away from drains, and the engineer records what was poured, the trucks received and the samples taken.

Ask your contractor about the pour day plan before it comes. A clear, detailed answer is a good sign that the project is in organised hands.

Shoring, props and site safety

Formwork gives concrete its shape. Shoring is what carries the formwork, the fresh concrete, the workers and the equipment until the element can support itself. In slabs especially, the shoring takes a very heavy load during the pour, and any weakness can cause permanent sagging in the slab or a dangerous collapse onto anyone below.

Common types of support

• Adjustable steel props, the most widely used today because they are strong and their height can be set precisely.
• Modular steel scaffolding, used for high ceilings and large areas because it spreads the load more evenly.
• Timber props, now used less for structural elements because their quality varies from piece to piece.

What to confirm before the pour

1. Props stand on firm ground or on boards that spread the load, never on loose soil or uncompacted fill.
2. Spacing between props follows the engineer or the manufacturer.
3. Props are truly vertical and braced to each other to prevent leaning.
4. The slab is given a slight upward camber where needed to offset natural deflection after striking.
5. On repeated floors, the shoring of each level sits on the same line as the one below.

Striking and re-propping

Slab props should only be removed once the engineer decides the concrete has gained enough strength. In multi storey buildings the floor below may need to stay partly supported while the slab above it is poured, because the weight of the new pour is transferred down to it through the shoring.

Safety on site

Shoring work is one of the most hazardous stages of construction for workers. Nobody should stand beneath a slab while it is being poured. Slab edges should be protected with barriers, workers should wear protective equipment, and the shoring should be checked after any strong wind or rain before work resumes.

A contractor who takes shoring seriously usually takes everything else seriously too. It is temporary work that disappears once the props are struck, but its effect stays in the flatness of the slab and in the safety of everyone who worked on the site. When you visit, a tidy, braced and properly founded prop layout is one of the clearest signs of a disciplined team.

Construction joints, expansion joints and where they go

No building can be poured in a single operation, so there are always joints between one pour and the next. The real question is not whether joints exist, but where they are placed and how they are treated. A well planned joint does not weaken the element. An unplanned joint caused by a sudden stoppage can become a weak point and a path for moisture.

Types of joint

• Construction joint is the boundary between two pours of the same element or of two connected elements, such as the line between the column pour and the slab pour.
• Expansion joint is a deliberate gap that separates two parts of a building so each can move with temperature changes without pressing on the other. The engineer specifies it in long buildings or where different parts connect.
• Contraction joint is mostly used in ground slabs and concrete pavements to guide cracking into a planned straight line instead of letting it appear at random.

Where a construction joint is placed

The engineer positions it in a zone where shear in the element is low. In beams and slabs this is usually near the middle of the span rather than at the supports. In walls it is horizontal at a set level. A joint should never be placed simply where it is convenient for the crew.

Preparing the joint before the next pour

1. Roughen the surface of the earlier pour and remove the weak, shiny top layer.
2. Clean it of dust, oil and timber.
3. Dampen it without leaving standing water.
4. Apply a bonding agent where the engineer requires it.
5. In water retaining elements, install a waterstop at the centre of the joint before the first pour.

The unplanned cold joint

A cold joint forms when a truck is delayed or the pump breaks down, and the concrete already placed starts to set before the next load arrives. The result is a weak plane between two layers. The pour plan must allow for this with standby trucks and a safe stopping point agreed in advance in case of delay.

Ask for construction joint locations to be shown clearly in the method statement before work starts. On site, check that pours stop only at those points and that each surface is treated before pouring resumes. These small details decide whether the element works as a single piece, exactly as the engineer designed it.

Embedded services and openings in concrete

A concrete frame does not stand alone. Electrical conduits, plumbing, air conditioning and drainage pipes all pass through it or run inside it. Every opening and every pipe has to be planned before the pour, because drilling through hardened concrete can cut reinforcement and weaken the element. This is one of the most common problems on projects where the structural team did not coordinate with the other trades.

What must be ready before the pour

• Pipe sleeves are pipes slightly larger than the service pipe, fixed in the formwork to leave a clean passage through a wall or slab.
• Electrical conduits inside slabs and columns, together with light boxes and outlets.
• Openings for air conditioning ducts in slabs and beams, at accurate sizes.
• Drainage openings and shafts, with the additional reinforcement around them.
• Fixing inserts for heavy equipment or light structures that will be hung later.

Important rules

Conduits must not be packed densely inside a column or beam without the engineer agreeing. A reinforcing bar must never be cut to make room for a pipe. A large opening in a slab needs extra steel around it as shown on the drawings. Conduits and sleeves must also be tied firmly so they do not float or move during pouring and vibration.

Coordination between trades

The most effective approach is a short meeting before each pour, attended by the electrical, plumbing and air conditioning technicians together with the site engineer. Each checks his own items inside the formwork, then everyone signs that the embedded work is complete. On projects run by a single contractor this coordination is easier, because all the teams work under one management.

After the pour

Clean out any concrete that has entered sleeves and conduits and confirm they are open. A blocked conduit inside a slab can mean breaking concrete later.

If an opening has to be made after the pour, do not leave it to a labourer. The engineer should fix the location after scanning for the steel and choose a suitable cutting method. At YAMIC we review embedded services with every trade before each pour as part of our concrete works scope, so the frame arrives ready for the services rather than fighting them.

Curing concrete after the pour

Curing is the stage that is neglected most often, even though it is one of the most important. Concrete does not simply dry. It reacts chemically with water and gains strength gradually. If it loses water too quickly, that reaction stops, surface cracks appear and the final strength is reduced. In a hot, dry climate, this is the difference between a durable structure and one that starts showing problems early.

Recognised curing methods

• Regular water spraying, making sure the surface never dries out between applications.
• Covering with wet hessian or plastic sheeting to reduce evaporation.
• Curing compounds sprayed onto the surface to form a membrane that holds moisture inside the concrete.

The right method depends on the element, its location and the weather. Roof slabs exposed to the sun need more attention than sheltered elements. Columns can be wrapped in hessian or plastic once the formwork has been struck. Large horizontal surfaces often combine methods, for example a curing compound followed by covering where the exposure is severe.

When curing starts and how long it lasts

The curing period is set by the engineer according to the cement type, the weather and the nature of the element. What matters is that curing begins as soon as the surface has stiffened enough and that it does not stop before the right time. Stopping early because the concrete looks dry and hard is a common error. In hot regions, disciplined curing is the real difference between sound concrete and concrete covered with fine hairline cracks.

Making curing a line item

At Yam Integrated Construction we treat curing as a separate item in the programme rather than a side task. We define who is responsible for it on site, how it is done and when it ends. That clarity protects the owner from surprises that would otherwise appear after handover, such as surface crazing, dusting floors or cracks that let moisture reach the steel.

When you review a quotation, look for curing to be mentioned explicitly with its method. If it is not there, ask. A contractor who plans curing from the start is one who understands what concrete needs after the trucks have left.

Surface finishing and dimensional accuracy

Concrete quality is not measured by strength alone. Another aspect matters a great deal to owners, namely dimensional accuracy and flat, true surfaces. A leaning column or an uneven slab means thicker plaster and higher finishing costs. It can also cause problems later when fitting doors, windows and marble.

Dimensional accuracy

Columns must be plumb and on their correct grid lines. Beams must be at their levels, and door and window openings at their sizes. Any deviation discovered after the pour is difficult to correct. That is why the engineer checks the formwork with a level and string line before pouring, and checks the element again after striking.

Finishing slabs

• Initial screeding with a straightedge to remove excess concrete and set the level.
• Floating and smoothing once the concrete starts to stiffen and the bleed water on the surface has disappeared.
• Power trowelling for floors that will stay exposed or need a very smooth surface.
• Roughening for surfaces that will receive another layer, so it bonds properly.

A frequent mistake is trowelling the surface while bleed water is still standing on it. This weakens the top layer and makes it flake or dust over time.

Falls on exposed surfaces

Surfaces exposed to rain, such as the roof, balconies and pavements, need falls towards drainage points. These falls should ideally be considered at the pouring stage or in a dedicated screed. A completely flat surface holds standing water, and that water finds its way in over time.

Fair faced concrete

On some facades, palaces and commercial projects the concrete is meant to stay exposed without plaster. This needs special clean formwork, a mix with consistent colour, careful vibration and planned positions for joints and tie holes so they read as part of the design.

Define the surface type for each element before signing and ask for it to appear in the quotation. Fair faced concrete and power trowelled floors need more work and materials than ordinary surfaces, and you are entitled to know the difference in advance.

Concrete tests and how to read the results

Testing is the only way to know what is happening inside concrete. The eye sees only the surface, while strength, density and uniformity need measurement. An owner does not have to carry out tests personally, but should know which tests are needed, when they are done and ask for the results in writing.

How to read cube results

Cubes are crushed in stages. An early result shows whether the concrete is developing in the right direction, while the final result is the one compared with the strength specified on the drawings. What matters is that every sample is linked to a specific element and a specific pour date. A result that cannot be traced back to its pour has no value.

What if a result comes back low

There is no need for immediate alarm, and no reason to ignore it either. The engineer first reviews how the samples were taken and cured, since a cube left in the sun may give a lower reading than the concrete actually placed. Tests on the element itself may then be requested. Based on those, the engineer decides whether the element is acceptable or needs strengthening.

What to ask for as an owner

• A register linking each set of samples to its element and pour date.
• Written, stamped laboratory results.
• Proper storage of samples on site until they are taken to the laboratory.

These papers can look like administrative detail. In practice they are the real assurance that the structure carrying your home or building was built as it was designed, and they become part of the record you keep for the life of the property.

Assessing and repairing defects after striking

However careful the work, some marks may appear on the concrete surface once the formwork comes off. The goal is not concrete without a single blemish, but a correct assessment of each observation and the right repair for it. Some defects are cosmetic, while others affect the strength of the element and the protection of its steel.

The correct assessment steps

1. Photograph the defect and mark its location on the drawing.
2. Gently remove weak material to find out how deep the problem goes.
3. Have the engineer judge whether it lies in a high stress zone, such as the underside of a beam or the head of a column.
4. Select and record the repair method before work starts.

Common repair methods

Surface defects are repaired with a suitable repair mortar after cleaning and dampening. Deep honeycombing requires removing weak concrete back to sound material, then filling with a structural repair mortar or by injection. Exposed steel is cleaned, protected and then covered with adequate cover. Structural cracks may need deeper study and strengthening solutions specified by the engineer.

What to avoid

• Covering honeycombing with ordinary plaster to hide it.
• Postponing the assessment until after plastering and painting.
• Treating exposed steel without first removing rust.

Prevention on site is always easier than repair after striking. Good vibration, tight formwork joints, correct spacers and careful curing remove most of the causes of these defects before they ever appear.

Make sure assessment and repair happen before plastering and finishing begin. Once the concrete is covered, a defect becomes hard to find and may later show as cracks or damp patches in new finishes. A record documenting each observation and its repair protects both owner and contractor.

Protecting foundations and buried elements

Foundations, tie beams and below ground walls disappear from view once backfilling is done, yet they are the most exposed parts of a building. They are in contact with soil, its moisture and its salts for the entire life of the structure. If moisture reaches the steel, corrosion starts where nobody can see it, until its effects appear in the walls and floors above.

The basic layers of protection

1. Dense concrete with a mix suited to the soil and thorough vibration that prevents pores.
2. Adequate concrete cover between the steel and the face in contact with the soil.
3. External waterproofing applied to surfaces in contact with soil after striking and before backfilling.
4. A protection layer over the waterproofing so stones do not tear it during backfilling.

Common waterproofing for buried elements

• Bituminous coatings, widely used on footings and tie beams.
• Waterproofing membranes, which give a stronger continuous layer on wetter sites.
• Cementitious and crystalline systems for elements that need high resistance to water.

How soil type and region affect the choice

On many sites in Riyadh and the central region the soil is relatively dry, though some of it contains salts that a soil report will reveal. In coastal cities in the Eastern Province and the western region, groundwater may be shallow and salty, which makes the cement type, the waterproofing and dewatering during excavation key decisions. In rocky areas the engineer pays close attention to levelling the bottom of the excavation and avoiding voids under footings.

Backfilling around buried elements

After waterproofing, backfilling is carried out with suitable soil in layers, each compacted and watered. Building rubble and timber offcuts must never be thrown into the excavation, because they decay and leave voids. Where the site needs it, the engineer may treat the soil against termites before the ground slab is poured.

What you can follow up yourself

Ask for photographs of the waterproofing before backfilling. Confirm it covers every surface, including the sides of tie beams and the tops of footings, and that backfilling does not start before the coating has dried. Ask the engineer to record acceptance of the waterproofing before backfill is allowed. Repairing a torn membrane before backfilling is simple, while repairing it afterwards means digging around the building again.

Special concrete elements such as tanks, manholes, culverts and rafts

Some concrete elements need experience beyond routine structural work. They deal directly with water, soil or very large loads, and small mistakes in them are costly to correct.

Concrete water tanks

A tank must be watertight in both directions. Water must not leak out, and groundwater and salts must not get in. That calls for a dense mix, construction joints treated with waterstops and suitable waterproofing inside and outside. The interior finish also has to be appropriate for stored water. You can read more about this specialised work on our water tanks service page.

Manholes and inspection chambers

Manholes are part of sewage and stormwater networks. They need accurate levels so that water flows in the right direction, and their concrete must withstand the damp environment and the gases present in sewer systems. A manhole set at the wrong level can affect the performance of the whole line it serves.

Box culverts

A box culvert is a closed concrete channel that carries flood and rainwater under roads or through developments. It resists soil pressure from the sides, traffic loads from above and moving water from inside. Its reinforcement is therefore dense and its formwork must be precise, with particular care at the joints between segments.

Raft foundations

Raft foundations are used for large buildings or on weak soil. A raft is a thick concrete slab that extends under the whole building. Pouring it requires planning for large volumes of concrete delivered continuously so that unwanted joints do not form. Mix temperature, delivery logistics and curing of such a large mass all need to be planned in advance with the plant and the pumping contractor.

Why these elements need engineering supervision

Each of these elements combines the usual concerns of formwork, steel and pouring with an extra demand, whether watertightness, flow levels, soil pressure or sheer volume. That extra demand is exactly where shortcuts cause problems. We deliver all of these elements within our concrete works service, with engineering supervision at every stage and inspection records before each pour, so that the element performs as designed once it is buried or filled.

Stairs, balconies and cantilevered elements

Some concrete elements are small in size but high in sensitivity. Stairs, balconies and cantilevered canopies are among the most important. People use them every day, stand on them or walk beneath them, and any mistake in their construction shows quickly as sagging, cracking or discomfort in use.

Concrete stairs

A staircase needs very precise carpentry, because every step must have the same height and the same depth. Even a small difference between one step and the next makes climbing uncomfortable and can cause people to trip. The formwork must allow for the thickness of the final finish, whether marble or tiles, so the steps stay equal after finishing. The steel at the start and end of the flight must also be anchored into the beams and slabs exactly as shown on the drawings.

Balconies and cantilevers

A cantilever is fixed on one side only and free on the other. Its main reinforcement is therefore at the top, not at the bottom as in an ordinary slab. This is a point where inexperienced crews sometimes go wrong by placing the steel in the usual position. The result is a weak element that may sag or crack where it meets the building.

• Cantilever steel must extend into the adjoining slab or beam for the anchorage length set by the engineer.
• Top steel must stay in position during the pour and must not be trodden down by workers.
• Cantilever props must not be removed early, because a cantilever is more sensitive than a normal slab.
• The top surface should fall away from the building so rainwater does not run inside.

Details that protect against moisture

The edge of a balcony or canopy needs a drip detail that breaks the path of water along its underside, so it does not run down the facade. This simple detail is formed in the formwork before pouring. When it is left out, dark streaks appear on facades, especially in cities with more rainfall such as Abha and Al Baha.

What to ask for

Ask the engineer to inspect the steel in these elements with particular care, and during the pour check that the top reinforcement has not moved. Ask too for the stair formwork to be checked against the finished floor levels, not only the structural levels. These few checks cost little at the formwork stage and save a great deal of breaking and rebuilding later.

Concrete and the climate of Saudi Arabia

The climate of Saudi Arabia varies widely, and each region affects concrete works differently. A pour in Riyadh is not carried out in the same way as a pour in Jeddah or Abha, even when the structural drawings are identical.

The hot, dry central region

In Riyadh, Qassim and Al Kharj the air is dry and temperatures are high for much of the year. Rapid evaporation is the main enemy of concrete here. It is therefore better to pour during the cooler hours, to use set retarding admixtures when needed and to start curing early and without interruption. Shading freshly placed surfaces and keeping aggregates and water cool at the plant also help the mix arrive in good condition.

The humid coast

In Jeddah, Yanbu, Dammam, Al Khobar and Jubail humidity is high and the wind carries salts that reach the steel over time. The soil itself may also be saline. The engineer therefore focuses on adequate concrete cover, the right type of cement and thorough waterproofing of buried elements. On these sites, the protection measures described for foundations become essential rather than optional.

The cooler southern highlands

In Abha, Khamis Mushait and Al Baha night temperatures can drop noticeably. Fresh concrete needs protection from the cold until it gains its strength. This is achieved by covering the pour and planning pouring times carefully, and in some cases by using accelerating admixtures as part of the mix design.

Adapting the method, not the design

Understanding these differences is part of a contractor's experience. The drawings stay the same, but the method adapts to the place through the pour time, the admixtures, the curing approach and the level of protection for buried elements. At Yam Integrated Construction we take the conditions of each city into account in the pouring and curing plan from the start, rather than reacting once problems appear.

When you discuss your project with a contractor, ask how the pour and curing plan will change for your city and season. A contractor who answers with specific measures for your site has thought about your concrete before the first truck arrives, which is exactly what you want from the team building your structure.

Documentation and quality records

Years after construction is finished, nobody will remember how the first floor slab was poured or where the construction joint in a wall was placed. The only thing that remains is what was documented on paper and in photographs. That is why documentation is part of the quality of concrete works, not an extra administrative task.

Records that belong in the project file

• Inspection records for steel, formwork and embedded services before each pour, signed by the engineer.
• Concrete delivery tickets for every truck, showing the mix, the time it left the plant and the time it arrived.
• Sample register linking cubes to elements and laboratory results.
• Curing log showing when curing started, when it ended and how it was done.
• Material certificates for steel, cement, admixtures and waterproofing.
• Photographs of hidden stages, such as steel before pouring and waterproofing before backfilling.
• Defect records and repairs, with photographs before and after.

Why this matters to you as an owner

For any future addition, such as a new floor or a rooftop pool, the engineer will need to know what is actually inside the structure. When selling, the file gives a buyer confidence in the building. If a problem ever appears, the file helps identify the cause quickly without breaking open the structure to investigate.

Daily photographs

A good photograph shows the element, its location in the building and its date. A reinforcement photo should show spacers, stirrups and laps. A pour photo should show vibration and curing. An organised set of photographs filed by floor and element is far more useful than a large collection of random pictures.

How we work at YAMIC

We send owners photographic updates for each stage. We work under engineering supervision, with sign off before every pour. At the end of the work we hand over a file containing inspection records, test results and material certificates, and the warranty is written and documented in the contract. We apply this on our projects in Riyadh, Jeddah, Dammam, Abha and other cities across the Kingdom.

If you are comparing contractors, ask each one what documents they will hand you at the end of the project. The answer tells you a great deal about how they will work during it.

What to prepare before starting your project

Before you contact any concrete contractor, prepare a few essentials. This saves time, makes the quotation more accurate and reduces disagreements during execution.

• Approved structural drawings from an engineering office, including reinforcement details and dimensions.
• A soil investigation report if available, since it determines the foundation type and required depth.
• A bill of quantities if one exists, to make comparing offers easier.
• The site location and access route, so the contractor can confirm whether pumps and trucks can reach it.
• The scope of work, whether you want labour only or full supply and execution.

Decide who supervises

It also helps to decide from the outset who will supervise the work. Will it be the contractor's engineer, an independent supervision office or both together? Being clear on this point defines who inspects the steel and formwork before each pour and who signs the inspection records. When this is left vague, inspections tend to be rushed or skipped when the programme gets tight.

Consider the full scope

If your project is a villa or a complete residential building, it may suit you to place the concrete frame and the remaining works with one party. One contractor managing structure, services and finishes removes many of the coordination gaps described in this guide. You can review our construction service to understand the full scope.

How we start with you

At Yam Integrated Construction we begin with a site visit and a review of the drawings, then send a written quotation and a clear execution programme. The quotation sets out the concrete grade for each element, the scope of formwork and steel, curing, testing and the documents you will receive at handover. We work from our head office in Riyadh and serve projects in Jeddah, Dammam, Makkah, Madinah, Abha and other cities across Saudi Arabia.

Coming to that first meeting with drawings, a soil report and a clear idea of scope means the conversation moves straight to how your structure will be built, rather than to what is still missing.