Concrete Scanning: Pharma Plant Cleanrooms and Tunnels

Why does a pharma plant need concrete scanning before drilling?

Because one core cut through a hidden conduit can shut a qualified area, trigger a deviation report and delay a batch. Concrete scanning in a pharma plant shows what is inside the slab or wall in minutes. A high frequency antenna sends electromagnetic waves into the concrete, and the return signal reveals rebar, conduits, sleeves and voids. Nothing is cut until the drilling points are cleared and marked.

Pharma buildings are altered more often than most factories. New process equipment, extra purified water drops, HVAC duct penetrations, revised airlock layouts and fresh instrument cabling all need openings in existing concrete. Each opening is a risk where the original drawings are thin, as they are on most older blocks.

What goes wrong when a pharma slab is drilled blind?

The common failures are a cut conduit that kills a running room, a pierced drain or water line, and a cut tendon or main bar. Each one costs far more than the scan. In a GMP area the bill also covers the investigation, cleaning and requalification after any unplanned event.

Older blocks carry a second risk: openings filled years ago without a record. A new core placed half over an old one can crack or break out. Radar shows these patches as a change in the concrete, so we mark them first.

How do we work inside cleanroom and GMP areas?

On the site's terms: inside its change control, gowning rules and cleaning procedures, with equipment and people entering only after QA has agreed the method. Under Schedule M good manufacturing practice, changes to qualified areas must be planned and recorded, and our paperwork is built to slot into that record.

• Method statement first: we send a short note covering the equipment, the surfaces to be scanned, the cleaning agent for our kit and the expected time in each room.
• Clean kit: radar units, cables and marking tools are wiped down with the agent your QA approves, then logged in through the material airlock.
• Gowned crew: our technicians follow your entry procedure for each grade of area, and stay only as long as the scan needs.
• No paint, no dust: marks go on with low-tack tape or a cleanroom-safe marker and are removed after drilling.
• Scan from outside where possible: many walls can be scanned from the corridor or service side, which keeps the clean side untouched.

What does the scan show in slabs, walls and service floors?

Bar spacing and cover, embedded conduits, sleeves, old core holes that were filled, and any pipe running inside a screed or a service floor. We mark safe drilling zones around each proposed opening, and flag anything we cannot read clearly so the engineer can move the hole a little or open it by hand.

Suspended slabs above a technical floor are scanned from the top surface, and the reading is checked against what can be seen from below. Where the slab is post-tensioned, finding the tendons is the main job, because cutting one is a structural problem. For the general method, read about RCC slab scanning.

Clean room expansion survey: a typical sequence

Most clean room expansion surveys run in four stages and are timed to the plant's shutdown or line-clearance window.

1. Walk-through with engineering and QA: we confirm the rooms, the openings and the cleaning and entry rules.
2. Outside work first: service corridors, technical floors and external yards are scanned while production runs.
3. Clean side in the shutdown: rooms inside the classified boundary are scanned in one planned entry, so the area is opened only once.
4. Marked-up layout: every cleared and every rejected drilling point is shown on your room layout, ready to attach to the change control record.

What should the site prepare before we arrive?

A room list with proposed openings, the latest floor and structural drawings you hold, and the entry and cleaning rules for each area. With these, concrete scanning in a pharma plant can be finished in one entry per area instead of several.

• Mark the proposed hole positions on the room layout, with sizes.
• Name one engineering contact and one QA contact for the visit.
• Confirm the shutdown or line-clearance window for classified rooms.
• Share any earlier scan results or core records for the same block.

Utility tunnel and yard mapping around the blocks

Outside the buildings, the risk shifts from concrete to the buried networks that connect them: effluent lines, solvent and process drains, fire mains, HT cables and storm water. On bulk drug sites, utility tunnels and pipe trenches link the production blocks to the tank farm, the boiler house and the effluent plant. Their routes are rarely straight and their covers are often hidden under later paving.

We detect and map tunnels, trenches and utility lines with radar and electromagnetic locators, open chamber covers where allowed, and record size, material and depth. This underground utility mapping completes the GPR survey of the site. The result is drawn on your site grid; details of CAD and GIS utility mapping explain the layers and formats we deliver.

Pharma site survey at a glance

A quick summary of what each part of a pharma survey covers.

If the design team needs quality levels for each buried service, see SUE survey for how we grade and report them.

Do we cover Baddi, Hyderabad and Ahmedabad?

Yes. Our engineers live in the main pharma clusters: the Baddi–Barotiwala–Nalagarh belt in Himachal Pradesh, the industrial areas around Hyderabad and the GIDC estates around Ahmedabad. A plant job opens at once, or a business day later at most. Slab scanning inside and yard mapping outside are done in one visit.

Hill-side units in Baddi sit on cut-and-fill terraces, where buried lines follow retaining walls and change level sharply. Older estates around Hyderabad and Ahmedabad have packed plots with shared boundary drains. The scan grid is planned around these ground conditions.

Rates for pharma plant work

Line and yard scanning is priced at ₹24 per metre for a standard GPR scan and ₹32 per metre with an L-section, GST extra. Plants outside Delhi NCR, which covers Baddi, Hyderabad and Ahmedabad, have a minimum order of ₹1,00,000; units inside NCR have a ₹50,000 minimum. Concrete scanning is quoted by the number of openings and rooms, after the walk-through. Whole-order discounts of 25%, 40% and 50% start above 100 km, 500 km and 1,000 km. They mainly help groups surveying several sites together.

Keep the record. A plant with current data collected on its underground utilities spends less on every later construction project, as the Mezux guide: as-built underground drawing explains. To book a walk-through, request a site visit and share the room list.

Frequently asked questions

Will the scan affect the room's classification?

It should not, if the agreed entry and cleaning rules are followed. Our kit is wiped down with your approved agent, enters through the material airlock and leaves no dust, because nothing is cut.

Can you give documents for our change control file?

Yes. We provide a method statement before the work and a marked-up layout with cleared and rejected points afterwards, both suitable for attaching to the change record.

Can radar find post-tensioning tendons?

In most slabs, yes. Tendons and their ducts show up clearly. Where they sit below a dense top mesh, we mark a wider no-drill zone and explain why.

Do you scan stainless steel or copper pipes in the slab?

Metal pipes reflect radar strongly, so they are among the easiest objects to find. Plastic conduits are fainter but visible in dry concrete, since radar picks up metallic and non-metallic objects alike.

How long does a cleanroom scan take?

A single room with a few openings often takes under an hour inside the clean side. Most of the time goes into entry, gowning and kit cleaning, which we plan in advance.

Can you also map the effluent and solvent lines in the yard?

Yes. We trace buried effluent, solvent, fire and power lines with radar and locators, and draw them on your site grid with depth and material.

Written by Saniya Parveen · Technically reviewed by Rahul Rai · Updated 8 November 2026