C‑DRONE
Tiled rooftops seen from above during a drone inspection

C-DRONE GUIDE · 22 AUGUST 2026

Industrial Foundry Drone Inspection: Casting Hall Roof, Chimneys and Stockyards, Method and Price

A roof structure that has absorbed years of thermal shock from shakeout venting with nobody ever climbing up to check it, a fume-capture chimney whose outer condition only gets a look during a chance furnace shutdown, a scrap-metal and moulding-sand yard nobody has re-measured since the last inventory : in an industrial foundry, classified under ICPE heading 2551 or 2552 depending on the metal worked, the building's outer envelope and the open-air stockpiles often remain the blind spot between two scheduled furnace shutdowns. The drone gives the operator a fast way to document, in a single campaign, the casting hall roof, the fume-capture chimneys and the stockyards, without putting anyone up at height or stopping production. Here is what it adds, what it doesn't replace, and the prices.

Published on 22 August 2026, reviewed on 22 August 2026 — regulations in force as of August 2026.

A facility classified in its own right, between melting and moulding

An industrial foundry falls under ICPE heading n° 2551 ("foundry of ferrous metals and alloys") or 2552 ("foundry of non-ferrous metals and alloys"), depending on the metal processed — a lead foundry falling instead under heading 2550. These three headings set the applicable regime (declaration, registration or authorisation) according to the tonnage produced; for sites under the declaration regime, the order of 30 June 1997 sets the general requirements — atmospheric emissions, noise, waste management — the operator must meet. At European level, the reference document on best available techniques for this sector (the "Smitheries and Foundries" BREF) further frames the technical choices of the largest sites, on the same logic as the IED directive for other industrial facilities.

This statutory monitoring of emissions and processes has nothing to do with the drone: it remains the job of the operator's fixed instrumentation and periodic checks by an accredited body. What the drone documents is the outer condition of the building and the structures around it — roof, chimneys, stockyards — on the same principle as for thermography of an industrial rotary kiln: a visual complement between two technical shutdowns, never a substitute for the measurement obligations.

Casting hall roof: a structure under repeated thermal stress

A foundry's casting hall often peaks at 10-15 metres to house an overhead crane, with a steel frame and a steel-deck roof pierced by vents and natural smoke-relief lanterns. This roof takes a particular thermal beating : heat surges and fine dust released at shakeout (demoulding still-hot castings), condensation from the temperature gap between the inside of the hall and the outside, corrosion accelerated by mildly acidic fumes. Access is rare and costly — a high-reach platform or a rope technician, under the same welcome protocol as a standard industrial site (prevention plan, coactivity). A high-resolution orthophoto paired with a thermal pass spots, in a single campaign, waterproofing defects, cladding corrosion and standing-water points that foreshadow a future leak.

Avoiding this height exposure is not a minor point : a study by María del Carmen Rey-Merchán and co-authors, published in 2021 in the International Journal of Environmental Research and Public Health and based on more than 290,000 fall-from-height accidents recorded in Spain between 2009 and 2019, shows that this type of accident disproportionately affects one-off, unfamiliar interventions — exactly the profile of an industrial roof check carried out once or twice a year (see the study on Google Scholar).

Fume-capture chimneys: out of reach, under filtration

Above every furnace — most often an electric induction furnace today, though some grey-iron foundries still run a coke-fired cupola — a capture hood draws the melting fumes into a duct network that ends at a bag filter before discharge through a chimney 15 to 40 metres high depending on the site. Monitoring the chimney's emissions is the job of fixed analysers and statutory periodic checks; the drone measures no pollutant concentration. What a thermal pass over the duct network and the filter housing does spot are useful indirect anomalies : a hot spot revealing pressure loss on a poorly insulated duct, a pierced duct section leaking hot air, an extraction fan malfunction showing up as a thermal imbalance.

A close inspection of the chimney shaft — cracks, corrosion of the liner rings or crinoline ladders, condition of the expansion joints — is planned by prioritising the areas to examine before the next furnace shutdown, exactly as described in our guide to thermography of an industrial rotary kiln for a cement plant. The report handed over points toward a check by the engineering firm or the filter's maintenance provider; it never substitutes for one.

Scrap, moulding sand and slag yards: regular volume tracking

A foundry stores several materials outdoors in piles or bays : the scrap metal feeding the furnace, the moulding sand — often regenerated on site and reused in a loop rather than bought fresh for every pour — and the slag, a melting residue sometimes recovered as aggregate after processing. Regularly re-measuring the volume of these stockpiles by drone photogrammetry, on the same principle as stockpile volume measurement in quarries and civil works, serves two concrete purposes : keeping the operator's material balance up to date (inflows, outflows, actual stock against the waste register and tracking slips) and catching unexplained discrepancies on a scrap yard, a material whose resale value makes it a recurring theft target on industrial sites.

The same pass also documents, via orthophoto, the condition of the storage areas — concrete slab, any containment under the slag yard — useful during an environmental inspectorate check or a justification request from the certifying body.

Method, flight framework and price

The mission is scheduled outside pouring peaks — usually between two melting campaigns — and follows the same welcome protocol as a standard industrial site : prevention plan, safety briefing with the site manager, compliance with traffic circuits that forbid any crossing with active casting areas. The drone never enters the buildings; it flies over the roof, chimneys and stockyards under the open category, subject to a prior declaration if the site borders a populated area, which is common in industrial business parks.

The deliverable pairs an orthophoto and a thermal pass of the roof with a report focused on the chimneys and duct network (hot spots, degraded insulation) and, if the mission includes it, a volume measurement of the stockyards. 2026 prices (excl. VAT) : €900 to €2,000 for a typically sized foundry (roof and chimneys), rising to €2,500-3,500 with the scrap, sand and slag yard volume measurement included; an annual follow-up campaign on the same flight plan typically costs 20 to 30% less than the initial one. Our thermal imaging drone page presents the service; request a quote stating the metal worked, the furnace type and the goal (roof only, roof and chimneys, or a full campaign with volume measurement).

Frequently asked questions about drone inspection of a foundry

Can the drone measure the chimney's emissions? No : that measurement remains the job of the fixed analysers and the statutory periodic checks required by the prefectural operating order. The drone spots indirect thermal anomalies on the ducting and the filter housing, which guide the follow-up check.

Who commissions this service? The foundry operator (private industrial group, automotive or aerospace subcontractor, art foundry), usually the maintenance or QHSE manager, for a preventive audit, ahead of a scheduled furnace shutdown, or to update the material balance.

Does the drone fly over the active melting hall? No : the mission is limited to the building's outer envelope — roof, chimneys, rooftop or ground-level equipment — and the stockyards, and never enters the workshops or flies over an ongoing pour.

Does the stockpile volume measurement replace the accounting inventory? No : it is an independent physical measurement, useful for reconciling the inventory and documenting the waste register, but the material accounting remains the operator's responsibility.

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