Rebar Inspection Before Pouring Concrete: A Homeowner's Checklist

A tape from the bar to the soil tells you more about the footing than any photo of the finished pour. The bottom mat needs 75 mm of concrete under it, held up by blocks, not stones. Illustrative photo.

Short answer: the hour before the pour is the only time anyone can see the steel, so that's when it gets checked, against the plans, by the licensed architect or civil engineer the owner is required to engage under Section 308 of the Revised IRR of PD 1096. Check the bar size and count against the schedules, the grade marks on the bars, the concrete cover (75 mm under a footing, 40 mm on columns and beams, 20 mm under an indoor slab, per NSCP 2015 Table 420.6.1.3.1), the lap length and where the laps sit, 135° hooks on every tie, closer tie spacing near the ends of columns and beams, the ties through the joints, and clean steel in tight, braced forms. The number most crews get wrong is the lap. For a 16 mm Grade 420 bar in 21 MPa concrete, the checker below gives a Class B tension lap of 910 mm, about 57 bar diameters, straight from the NSCP development-length table. If your crew laps at 40 bar diameters (640 mm for that bar), that's 270 mm short.

The checker gives you the numbers for your own element and bar. Below it: why the pour is a hold point and who signs it off, then each check in the order you'd walk the site, and what to do when something fails.

1. The Pour Is a Hold Point: Who Signs Off

A hold point is a stage the work can't pass until someone with authority has checked it. On a concrete house every structural pour is one: footings, each storey's columns, beams and suspended slab. Afterwards, cover, laps and ties can only be checked by breaking concrete, and no scan tells you a hook was bent to 90° instead of 135°.

The rules put this on the owner. Under Section 308 of the 2004 Revised IRR of PD 1096, the owner issued the building permit "shall engage the services of a duly licensed architect or civil engineer to undertake the full time inspection and supervision of the construction work" (308.1). It may or may not be the designer (308.2). A logbook is kept at the jobsite recording "the actual progress of construction including tests conducted, weather conditions and other pertinent data" (308.4), and on completion that architect or civil engineer submits it, signed and sealed, to the Building Official with a Certificate of Completion (308.5).

The permit repeats it. Section 304.5(c)(iii) makes a daily logbook kept by the supervising architect or civil engineer, open to the OBO inspector, a condition of the building permit. Section 304.5(a) cites Civil Code Article 1723: the engineer or architect who supervises is solidarily liable with the contractor if the building collapses from defective construction or inferior materials. That's why a real supervisor won't sign off on a cage he hasn't seen.

So the sign-off is a logbook entry before the pour, by the licensed supervisor: element, gridline, what was checked and corrected, signature. Not the foreman's "okay na, sir." We found no later issuance changing Section 308. Building from abroad? Our guide to building while abroad explains why a relative with a phone can't do this, and stages of house construction shows where each hold point falls.

2. Before You Walk the Site

• The structural sheets for that element: footing, column and beam schedules, the slab plan, and the general notes, which carry f'c, bar grade, cover, laps and hook details. The general notes are the sheet most often left in the office.
• A steel tape. Cover is measured from the outside of the outermost bar (usually the tie) to the form or soil. A cheap caliper settles bar-size arguments; measure the core between the ribs.
• Your phone. Photograph each check with the tape visible and the gridline written on cardboard in the frame. Our progress verification guide covers photos that count as evidence, and the daily report format shows how to log them.

Do the check the day before the pour, not with the ready-mix trucks already on the road.

3. The Bars: Size, Count, Grade Marks, Condition

Size and count. Count the main bars in each footing, column and beam against the schedule. A column marked 8-16mmø should have eight 16 mm bars, not four 16 and four 12. In beams, count top and bottom bars separately, at midspan and at the supports, because the schedule usually changes between them.

Grade marks. Philippine deformed bars are made to PNS 49:2020. DTI-BPS made it the reference standard (replacing PNS 49:2002) through Memorandum Circular 21-07, and set market enforcement of the new markings from 1 January 2023 under MC 21-1744. Under DTI-BPS marking rules for PNS 49:2020 bars, each bar is embossed at about one-metre intervals with:

Each bar also carries the maker's BPS pre-qualified alphanumeric logo and the bar size; each bundle has a tag with size, length, grade, lot number and PS licence or SOC number. Don't read grade by paint: DTI-BPS says there are no painting requirements on bar ends. If the plans call for Grade 420 and the bars read "3", that's Grade 280, and every lap and beam designed for 420 MPa steel is now short. "Grade 40" and "Grade 60" on site are the ASTM inch-pound names for the same two strengths; our rebar price guide lists both.

Mill certificates. NSCP Section 426.6.1.2(a): "Mill test reports for reinforcement shall be submitted." Ask for them. In a special moment frame, Section 420.2.2.5 also caps actual yield at no more than 125 MPa above the specified value and needs an actual tensile-to-yield ratio of at least 1.25, which only the mill report shows.

Condition. Rust and mill scale are acceptable if a wire-brushed sample still meets the ASTM minimum dimensions and weight per metre (426.6.1.2(b)); flaking scale that leaves the bar visibly thinner isn't. And at the pour, bars must be "clean of mud, oil, or other deleterious coatings that decrease bond" (426.6.1.2(d)). Footing cages dragged through a wet excavation get cleaned first.

4. Concrete Cover and Spacers

Cover is the concrete between the outermost steel and the surface. Too little and the steel rusts, the rust expands and the concrete spalls. NSCP 2015 Table 420.6.1.3.1 sets the minimum for cast-in-place, non-prestressed concrete:

Cover is measured to the tie, not the main bar. The 75 mm applies to the bottom and sides of a footing poured against soil; whether a lean-concrete blinding layer counts toward it is your engineer's call, not the crew's. And a formed column stub that will be backfilled is "in contact with ground": 50 mm for 20 mm and larger bars.

How much short is too short? Table 426.6.2.1(a) lets built cover fall short by no more than the smaller of 10 mm (12 mm where d is over 200 mm) and one-third of the specified cover; its footnote cuts that to 6 mm for formed soffits, the underside of a slab or beam. So a 40 mm column cover can't go below about 28 to 30 mm, a beam bottom below 34 mm, or a 20 mm slab cover below 14 mm.

Spacers. Section 426.6.2.2(a) requires bars "supported to prevent displacement beyond required tolerances during concrete placement": precast cover blocks or plastic spacers under every mat and on the sides of cages, and chairs under a slab's top mat. Stones roll, broken CHB crumbles, and wood rots into a channel for water to reach the steel.

5. Lap Splices: Length and Location

A lap splice passes the force from one bar to the next through the concrete between them. Too short, and the bar pulls out before it yields. On site the number usually comes from habit, not the plans.

The length starts from the development length ℓ_d, simplified Table 425.4.2.2:

ℓ_d is at least 300 mm (425.4.2.1; the lap in 425.5.2.1 starts from ℓ_d before that minimum). From Table 425.4.2.4: λ = 1.0 for normal-weight concrete, ψ_e = 1.0 for uncoated bars, ψ_t = 1.3 for a horizontal bar with more than 300 mm of fresh concrete below it, otherwise 1.0. The longer equation in 425.4.2.3 can give less; if your engineer used it, the plans show the result.

The lap comes from Table 425.5.2.1: Class B, the greater of 1.3ℓ_d and 300 mm, unless the steel provided is at least twice what's required and no more than half the bars are spliced there, when Class A (1.0ℓ_d) is allowed. You can't confirm that on site, so check against Class B unless the plans say otherwise.

For the common house case, a 16 mm Grade 420 bar in 21 MPa concrete in the first spacing row: ℓ_d = 420 × 16 / (2.1 × √21) = 699 mm, and the Class B lap is 1.3 × 699 = 908, rounded up to 910 mm (57 bar diameters). Grade 280 bars: 610 mm. Grade 420 in tight spacing: 1,370 mm. Pure-compression laps can be shorter (0.071f_yd_b, at least 300 mm, 425.5.5.1), but columns in a special moment frame must be lapped as tension splices (418.7.4.3). No lap splices for bars over 36 mm, except compression laps to a 36 mm or smaller bar (425.5.1.1, 425.5.5.3).

The location matters as much:

• Special-moment-frame columns: laps "shall be permitted only within the center half of the member length," as tension laps inside end-zone hoop spacing (418.7.4.3). Lapping just above the slab, where the next pour starts, is exactly where the code forbids it.
• Special-moment-frame beams: no laps in the joint or within twice the beam depth of its face, and hoops over any lap at no more than d/4 or 100 mm (418.6.3.3).
• Everywhere: splices "shall be made only as permitted in the construction documents, or as authorized by the licensed design professional" (426.6.2.2(c)).

6. Hooks: Standard and 135° Seismic

Two tables in NSCP 2015 Section 425.3 cover every hook you'll see:

Our scan prints the 90° tie-hook extension for 10–16 mm bars as "46_b"; we read it as a misprint for 6d_b, as in the 135° row.

The seismic hook (425.3.4) is a bend of at least 90° for circular hoops "and 135 degrees for all other hoops," engaging the longitudinal bar, with the extension projecting "into the interior of the stirrup or hoop." Crossties (425.3.5) have a seismic hook at one end, at least a 90° hook at the other, and alternate end for end.

Why it matters: in an earthquake the cover spalls off first. A 90° tie hook sits in that cover, opens up, and the column bars buckle outward. A 135° hook is anchored in the core that's still there. Look at every hoop. With 10 mm ties the extension must be at least 75 mm, since 6 × 10 = 60 mm is less.

7. Column Ties: Which Rules Apply to Your House

Most online checklists give one tie spacing for every column. NSCP 2015 has three sets of rules, depending on how your engineer designed the house for earthquakes:

• Special moment frame (SMF), Sections 418.6 to 418.8. Most of the Philippines is Seismic Zone 4; Section 208.4.4.1 makes only Palawan (except Busuanga), Sulu and Tawi-Tawi Zone 2. Table 208-11A doesn't permit concrete ordinary or intermediate moment frames on their own in Zone 4 (an intermediate frame is allowed only in a dual system with special shear walls), so a house whose concrete frame alone resists the earthquake needs a special moment frame. That's the default in our column size guide too.
• Intermediate moment frame (IMF), Section 418.4, for Zone 2.
• Columns not in the seismic frame, such as gravity columns where shear walls take the earthquake. In Zone 4 they still fall under 418.14: at minimum, hoops with seismic hooks at no more than the smaller of 6d_b and 150 mm over the full height (418.14.3.2(b)), and the special-moment-frame column reinforcement rules (418.7.4 to 418.7.6) if the designer didn't check drift (418.14.3.3). The general tie rule of 425.7.2.1 alone applies only in Zone 2, or to CHB tie columns designed under the masonry chapter.

In our experience many small provincial houses get columns detailed like ordinary tied columns, 200 × 200 mm with ties at 150 or 200 mm all the way up, whatever the drawings say. You can't fix that on pour day. You can check the cage against the plans and ask the engineer which system they designed. If it's a special moment frame:

For the checker's default (300 mm SMF column, 16 mm bars, 10 mm ties, 2.7 m clear height), the spacing limits of 418.7.5.3 give 75 mm over the bottom and top 450 mm, and no more than 95 mm in between (6 × 16 = 96, rounded down). Inside ℓ_o the hoops must also carry the confinement steel of Table 418.7.5.4: with a single 10 mm Grade 420 hoop and 40 mm cover that works out to about 55 mm (b_c = 220 mm, A_ch = 48,400 mm², two legs = 157 mm²). With Grade 280 ties it drops to about 35 mm. 12 mm hoops or a crosstie bring it back to 75 mm. The designer's spacing on the plans governs. Ties at 150 mm everywhere don't match an SMF design. Ties are at least 10 mm around bars up to 32 mm and 12 mm around 36 mm (425.7.2.2), and an SMF column is at least 300 mm on its shortest side (418.7.2.1).

The close hoops, with the same confinement steel, continue through the beam-column joint (418.8.3.1 applies 418.7.5.2 to 418.7.5.4), relaxed to half the steel and 150 mm spacing only where beams at least three-quarters of the column width frame into all four sides (418.8.3.2). Missing joint ties, left out because they're hard to place once the beam bars are in, are among the defects we find most.

8. Beams and Beam-Column Joints

• End hoops. In an SMF beam, hoops over twice the beam depth from each column face (418.6.4.1), the first within 50 mm, spaced at the smallest of d/4, 6 main-bar diameters and 150 mm (418.6.4.4); elsewhere, stirrups with seismic hooks at no more than d/2 (418.6.4.6). IMF beams: d/4, 8d_b, 24 tie diameters or 300 mm over 2h (418.4.2.4), d/2 elsewhere (418.4.2.5).
• At least two continuous bars top and bottom (418.6.3.1, 418.4.2.1).
• Bars ending in a column reach the far face of the confined core (418.8.2.2). Stopping at the near face is a defect.
• Bars passing through a joint need a column at least 20 bar diameters deep in that direction (418.8.2.3). So 16 mm continuous beam bars need a 320 mm column; a 300 mm column doesn't qualify. Ask the designer before the pour.
• Bar spacing. Clear spacing in a layer at least the greatest of 50 mm, d_b and 4/3 of the aggregate size (425.2.1, as printed); layers directly above each other, 25 mm apart (425.2.2); column bars at least 40 mm, 1.5d_b or 4/3 aggregate (425.2.3).

9. Footings and Dowels

• Depth and plan size against the footing schedule, before looking at steel. A cage in a shallow hole is a shallow footing.
• 75 mm cover on cover blocks, soil off the bars. Bottom mat size, count and spacing both ways as scheduled.
• Column dowels on the right grid, same number and size as the column, 90° hooks on the mat. A hooked bar develops over ℓ_dh, the greatest of f_yψ_eψ_cψ_rd_b/(4.17λ√f'c), 8d_b and 150 mm (425.4.3.1): about 352 mm, 360 rounded up, for a 16 mm Grade 420 bar in 21 MPa concrete with the ψ factors at 1.0. A footing too thin for that plus 75 mm cover is a design question, not a site fix.
• Dowels stick up at least the scheduled lap, and ties hold them in place as detailed.

10. Slabs, Formwork, Shoring, Conduits

• Slab thickness as shown on the slab plan. Mark it on the edge form. Our slab thickness calculator explains the NSCP minimum.
• Bottom bars on 20 mm cover blocks for an interior slab (Table 420.6.1.3.1); top bars over the supports on bar chairs, at the scheduled height, and not trampled flat by the crew walking on them. Put planks down for the pour crew.
• Conduits between the mats, not on top of the top bars, and no bar cut or bent aside to make room. Section 426.6.3.1 has bars bent cold before placement and bans field bending of bars partly embedded in concrete "except as shown in the construction documents or permitted by the licensed design professional."
• Sleeves for pipes through beams, where the engineer approved, placed before the pour. Coring a beam later is how a drain line cuts a main bar.
• Formwork tight at the joints (leaks cause honeycombing), clean inside, plumb, and braced so it doesn't bulge.
• Shoring on firm bearing, not loose fill, at the spacing the plans call for. Our concrete mix guide covers the concrete side of the pour.

11. When the Check Fails

It will, often. Nearly every cage we check has something: a missing joint tie, a 90° hook, a face without cover blocks. What matters is what happens next:

1. Hold the pour. Moving it costs a day. Pouring over a known defect costs the element.
2. Write a punch list: gridline, element, what's wrong, what the plans require, photos. Put it in the logbook.
3. Sort the fixes. Site fixes the crew can do now: add ties, rebend hooks, add cover blocks, clean the steel, add a bar to lengthen a lap. Design questions need a written answer from the engineer of record: a lap in a forbidden zone, the wrong grade delivered, a footing too thin for the hook, a column too small for the beam bars.
4. Re-inspect before signing. Not "fixed na, sir" by Viber. See it, or see photos with the tape in them.
5. Already poured? Then it's testing, cores or breaking out; our core testing guide covers what the code accepts.

If the contractor refuses to fix or pours anyway, write it down, stop the progress payment for that element, and read our pakyaw vs contractor guide for who carries which risk. Before signing with anyone, check they're licensed: our PRC and PCAB verification guide takes ten minutes.

12. Is It Worth Hiring an Independent Engineer?

People ask this as if an engineer on the pour were optional. It isn't: Section 308 already requires the owner to engage a licensed architect or civil engineer to inspect and supervise. The real question is whether that person works for you or for the contractor. In a design-and-build or a "complete package" contract, the supervising engineer is often the contractor's own. That's legal, but it means the person checking the steel is paid by the person who placed it.

An independent check is worth it on the pours that carry the house: footings, first-storey columns, and the second-floor beams and slab. A cage with laps 270 mm short looks exactly like a good one once the forms come off. It's probably not worth paying twice if your supervising engineer is already independent of the contractor, is at every pour, and keeps a real logbook with photos. Ask to see it.

Frequently Asked Questions