GI, PI, spiral and grease duct fabricated to drawings for MEP contractors, fit-out companies and consultants. Supply only, or supplied and installed, with every piece labelled and delivered in sequence.
Duct is not a shelf product. Almost every metre is made to the dimensions of a particular building, which is why duct fabrication rather than duct supply describes the work.
We fabricate:
Orders run from a handful of fittings for a site that has hit a clash, up to a full floor of a fit-out.
GI duct is galvanised steel sheet formed and joined into rigid sections. The zinc coating is why GI duct sheet survives decades in a ceiling void that would rust plain steel. It is the default commercial duct material and still the right answer for a large share of Dubai work.
The most common question a trade buyer asks is what gauge the duct will be. The honest answer is that the specification sets it, not the fabricator. Sheet thickness follows the duct's largest dimension, the pressure class, and the joint and stiffening system used, so bigger duct and higher pressure both push the sheet thicker.
Where no gauge is stated, we do not guess and we do not quietly pick the cheapest sheet that will hold its shape. We ask what pressure class and standard apply, confirm the gauge in writing, and cut after that is agreed. Gauge is the one thing a consultant will physically measure.
Rectangular GI duct is typically joined with a flange system at the ends of each section, gasketed with the corners fixed, and longitudinal seams along the section. Larger sections need stiffening, because a wide flat panel of steel will drum, flex and transmit noise under pressure if nothing braces it. Cross-breaking or beading the sheet, and tie rods or external stiffeners where the size calls for it, keeps a large duct quiet and dimensionally stable.
Sealing is the other half. A duct that leaks is cooling the ceiling void instead of the room, and that leakage is paid for every hour the plant runs. Joints, seams, spigots and access panel frames are sealed during fabrication.
GI duct is not insulated when it leaves fabrication. The steel is formed first and the insulation applied afterwards, usually as a wrap or board on the outside face with a vapour barrier over it.
That sequence matters more in Dubai than almost anywhere. A duct carrying cold air through a hot, humid ceiling void is a cold surface in wet air, and if the vapour barrier is broken, moisture condenses on the steel exactly as it does on a cold glass. The water soaks the insulation, destroys its performance and eventually stains the ceiling below. The failure points are always the same: hangers that pierce the barrier, corners, branch connections, wall penetrations, and the connection at the grille or unit. Specify GI duct insulation with the same care as the steel and budget the labour.
GI ductwork is right for higher pressure systems, kitchen extract and other hot or greasy duties, fresh air, plant room and riser ductwork with a long life ahead of it, anywhere the duct takes knocks or foot traffic, exposed round and spiral work, and any job whose specification simply says galvanised steel. It is the wrong call when the ceiling void is shallow and every millimetre counts, or when the programme cannot absorb steel plus a separate insulation activity. The honest drawbacks: heavy, slower to install, and it needs a separate insulation trade after it is up.
Pre-insulated duct, universally called PI duct on UAE sites, is rigid insulation board faced with aluminium on both sides, cut and folded into duct sections with the insulation integral to the duct wall. There is no separate insulation trade afterwards, because the insulated duct panel is the duct.
PI ductwork is very widely used in UAE residential and light commercial work, and if you are fitting out villas and apartments in Dubai it is probably what you are pricing: a fraction of the weight of steel, faster to install, and it fits shallow ceiling voids that steel plus external insulation would never make.
Pre-insulated duct panel is made in different thicknesses, and the thickness is specified rather than picked at random. It governs two things at once: the rigidity of the finished duct and its thermal performance. Thicker panel spans further unsupported, resists denting and insulates more. Thinner panel is lighter and cheaper and is fine on smaller sections and short runs.
Because the insulation is structural in a PI system, you cannot separate the two decisions the way you can with GI, where gauge and insulation thickness are chosen independently. Facing thickness is a second specified variable, and the outer face takes the damage. We will not substitute a thinner panel than the specification calls for because it prices better.
PI duct suits villa and apartment systems, hotel rooms, offices and retail units, shallow ceiling voids, and renovation work where speed matters. It is the wrong choice for kitchen grease extract, high pressure systems, roof-exposed duct without protection, and plant rooms and risers where duct gets knocked.
And here is the drawback nobody puts in a brochure: pre insulated ductwork does not forgive another trade standing on it. A ceiling void on a live fit-out has electricians, sprinkler fitters and ceiling grid crews working above the same duct. Steel shrugs off a boot. Panel takes a permanent dent that restricts airflow to everything downstream for the life of the building. That is a routing and protection problem rather than a reason to avoid the material.
Plenty of buildings use both, and a mixed system is normal rather than a compromise: GI on risers, plant connections and kitchen extract, PI on the horizontal distribution above the ceilings. We fabricate both, so we have no reason to steer you either way.
Round duct moves air more efficiently than rectangular duct of the same capacity and is stiffer for its weight, because the shape carries the pressure. GI spiral duct is made by helically winding and locking a strip of galvanised sheet into a tube, which produces the visible spiral seam that names it and makes it stiff without added bracing. GI round duct in plain sections, with matching bends, tees and reducers, is fabricated alongside it.
Two uses dominate. The first is distribution in warehouses and industrial units, where round is simply the better shape.
The second is architectural. Exposed spiral duct is a deliberate design feature in restaurants, cafes, showrooms, gyms and stripped-back offices. When duct is on show the standard changes: seams, joints, hangers and alignment are all part of the finish, and a run that is dimensionally correct but visibly off level is a snag. Flag exposed work at enquiry stage. Pre insulated spiral ductwork exists too, though the great majority of round work we fabricate is galvanised steel.
Flexible duct is the insulated hose used for the last short run between a rigid branch and a grille, and for the connection into a fan coil unit. It is a legitimate, standard part of a duct system when it is specified and fitted correctly, and it is one of the most abused products in the trade when it is not.
We supply flexible ducting in the diameters the job calls for, in insulated and uninsulated form. Insulated flexible duct carries a sleeve of insulation and an outer vapour barrier over the inner core, and in Dubai that vapour barrier matters as much as the insulation itself, because a cold flexible run in a hot ceiling void will sweat wherever the barrier is broken or badly taped at the collar. Aluminium flexible duct suits extract, ventilation and higher-temperature applications where a plain plastic core is not the right product. Semi-rigid ducting sits between the two, holding its shape better over a longer span.
The size question comes up constantly, so to be plain about it: the correct diameter is the one the airflow for that room requires, not the one that happens to fit the collar already on the branch. Reducing a run to squeeze it into an undersized spigot is a guaranteed complaint later, and it is the reason so many bedrooms in this city never cool properly.
Where flexible duct is the right product
Where it is the wrong product
Fitted properly, flexible duct is pulled taut rather than left slack, supported at regular intervals so it cannot sag, kept to a generous bend radius, clamped and sealed at both ends, and has its vapour barrier made continuous at every collar. Fitted badly, it silently strangles the room at the end of it while the AC unit runs perfectly.
Flexible connectors are a different item that gets called by a similar name, so it is worth separating the two. A flexible connector is the short fabric or coated-fabric section fitted between a fan, an air handling unit or a fan coil unit and the rigid ductwork it feeds. Its job is to stop the vibration of the running plant from travelling into the duct system and through the building structure, and to allow slight movement and thermal expansion at the connection. A failed or missing flexible connector is a common cause of a duct system that hums or drums through a ceiling when the plant starts. We supply and fit these alongside the ductwork, and we replace them when they have gone hard, split or been painted solid.
We supply flexible duct and connectors on their own, or as part of a fabricated duct package with the rigid sections, fittings and accessories delivered together.
Kitchen extract duct is a different build from comfort-cooling duct, and treating it as ordinary ductwork with a fan on the end is one of the more dangerous shortcuts in the trade. Grease-laden vapour leaves a commercial kitchen, cools as it travels, and deposits a flammable film inside the duct along the whole run. That drives how it is made:
Grease duct is fabricated in carbon steel or stainless steel to the thickness the specification calls for. Galvanised steel is not a grease duct material, because zinc volatilises at fire temperatures, and pre-insulated panel is not a grease extract material either.
If you are running a kitchen rather than building one, the system also needs cleaning on a schedule matching how hard it works: kitchen hood and duct cleaning, which we also do, and a large part of why we know what a bad grease duct looks like from the inside.
Straight duct is the easy part. Fittings are where the labour, the accuracy and most of the cost sit. Fabricated alongside the main runs:
A word on the duct access panel, because it is the item most often cut from a package to save money and the one most regretted. Panels go at filters, dampers, fire dampers, coils and any bend that will need cleaning. Without them a system cannot be inspected or cleaned properly, and every future service visit becomes a ceiling repair.
The process is deliberately boring, because on a fabrication job the surprises are all bad ones.
1. Drawings or survey. Most trade orders arrive as shop drawings or a duct schedule. If drawings do not exist, we survey the site and produce the dimensions ourselves. Which applies changes who owns the dimensions, so it is stated in the quote.
2. Specification confirmed in writing. Material, gauge or panel thickness, pressure class, joint system, sealing, insulation, fittings, dampers and access panels. Anything ambiguous is asked about now rather than discovered at delivery.
3. Cutting list. The drawings are broken into individual pieces with dimensions, quantities and reference marks.
4. Cutting, forming and checking. Sheet or panel cut, seams and flanges formed, sections assembled, sealed and stiffened where the size calls for it. Dimensions, squareness, fitting angles and spigot positions are checked against the drawing before anything is loaded, not after it is on site.
5. Labelling. Every piece marked with its drawing reference. On a job with three hundred pieces this is the difference between an installer working and an installer standing in a corridor with a tape measure.
6. Delivery in installation sequence. Duct is bulky and site storage is scarce. We deliver in the order the installer needs it, in quantities the site can take, planned around the lift booking and permitted working hours. Labelling and sequence sound like administration, but they decide whether a package saves an installer time or costs him a day.
Real duct sections being prepared and assembled for installation on site.
Dimensional accuracy is what a trade buyer is actually paying for. Everything else on this page is table stakes.
Here is what a duct that is out by a small margin does. It does not fit, and the installer, who is on a programme and will not send it back and wait, makes it fit: packs a joint, forces a flange, cuts a slot, or bridges a gap with sealant. It passes a visual inspection and then leaks for the next fifteen years.
The costs land in this order: rework and returns, the visible cost and the smallest one; programme delay while a crew waits on replacements; leakage, because every forced joint is a leak paid for in energy for the life of the building; noise; failed testing at handover; and a system that never balances.
Tolerances are set by the standard or specification the job is built to, and we fabricate to the tolerances yours states. Where it states none, we agree them in writing before cutting, and we will say plainly if a drawing is not dimensioned well enough to fabricate from.
If that is the standard you need held, send the drawing set across and we will tell you before we quote whether it is dimensioned well enough to fabricate from, and where it is not.
There is no minimum order. We fabricate a handful of fittings for a single room as readily as a full floor of a fit-out. Contractors who need three transitions and a plenum tomorrow are turned away often enough that it is worth saying plainly: that is a job we take.
Both are offered, and the difference is not price. It is where responsibility sits.
We fabricate to your drawings and your dimensions and deliver to your site. You install.
The drawings are yours, and so are the dimensions on them. If a drawing says a section is a certain size, we make it that size. If the building turns out to differ from the drawing, that is a variation, not a defect. This is the normal arrangement with MEP contractors and fit-out companies who have their own install teams.
What we do in return: we flag anything on your drawings that looks wrong before we cut it. A fitting that will not assemble, a branch that clashes with itself, a dimension that contradicts another sheet. We are not signing off your design, but a fabricator who spots an error and cuts it anyway is no use to anybody.
We fabricate and install, and the whole package is ours: dimensions, fit, sealing, insulation, supports, access and the finished result. Site measurement is our responsibility, so a duct that does not fit is our problem. This is the right route for end clients, building owners and main contractors who would rather hold one party accountable than manage the seam between a supplier and an installer. Where the client wants ductwork kept on a schedule after handover, the fabrication and the ongoing maintenance sit under one contract.
Warranty terms for your job are confirmed in the written quotation. It applies to the installation on a supplied-and-installed package. On supply only there is no installation to warrant, and the dimensions on your drawings stay yours.
Duct fabrication here is generally specified against one of a small number of recognised documents, and which one applies is set by the consultant or the client, not by us.
We fabricate to the specification and drawings supplied. The specification governs material, gauge or panel thickness, pressure class, sealing and leakage requirements, and we confirm all of it in writing before cutting. Name the standard on your enquiry: it changes the material take-off and therefore the price.
Duct is priced per job, not per metre off a list, and much of what looks like a price difference between duct suppliers is a difference in what is being priced. What moves the number:
We will not publish a rate, because a rate quoted without the drawing in front of us changes later. Send the drawings through the quote form and you get a written quote before any work begins.
Rectangular GI on an automated coil line with Pittsburgh lock seams, and TDF or TDC flanged connections rather than slip-and-drive where the spec calls for it. Spiral and round for exposed runs. PI panel cut and assembled for pre-insulated work. Plasma cutting for fittings and transitions.
Gauges to the duty and pressure class: 24 gauge for low pressure and small sizes, 22 gauge through the mid range, 20 gauge on large or high-pressure runs. Fabricated to DW144, the standard most Dubai specifications reference, or to SMACNA where a US-specified project calls for it. We state which on the submittal.
Industrial and warehouse fabrication concentrates in Jebel Ali and JAFZA, which run their own permitting route. We work to whichever applies.
Related trades: duct installation, duct cleaning, AC installation, office fit-out and commercial maintenance.
Transparent pricing with no hidden fees. Final price confirmed after assessment.
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Send the drawings through the quote form or bring a sample section, and we will quote the fabrication, the delivery and the installation if you need it.
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