PEMB Anchor Bolts in Spokane: Who Designs the Foundation, Setting Tolerances and Inspections (2026)

Every column of a pre-engineered metal building (PEMB) is held down by anchor bolts cast into the concrete, and they have to be right before the steel ever shows up. The building manufacturer tells you where the bolts go, but not how deep they go or what the footing under them looks like. Here's who designs what, the tolerances the steel industry allows, the inspections Washington's code calls for, and what happens when a bolt ends up in the wrong spot.

Anchor bolts, anchor rods: same thing

The steel industry calls them anchor rods, and most builders and owners call them anchor bolts. Either way, they're threaded steel rods cast into the footing or pier that the column base plates bolt down to. On a PEMB they do more than keep the building from sliding:

• Uplift: wind tries to lift the roof and walls, and the rods hold the frame down
• Shear: wind and seismic loads push sideways at the base of each column
• Frame thrust: rigid frames push outward at the base, which is why many PEMB foundations also have hairpins or tie rods cast in to carry that thrust into the slab or across the building

Who designs what

This is the part most kit buyers miss. The Metal Building Manufacturers Association (MBMA) spells it out in its Common Industry Practices (2024 edition), section 3.2.2:

• The manufacturer is not responsible for the design, materials or workmanship of the foundation
• The anchor rod plan the manufacturer prepares is meant to show only the location, diameter and projection of the rods
• The manufacturer does provide the loads the building puts on the foundation, usually called column reactions
• Embedment, tie rods and the foundation itself are the responsibility of the owner's registered design professional or engineer of record, designed for the building's reactions, any other loads and the soil on the site

Ceco Building Systems, one of the larger manufacturers, says the same in its FAQ: anchor rods aren't in the building package because they rely on the pier reinforcement for their strength, so they belong with the concrete package along with rebar, tie rods and hairpins, and the foundation engineer sets the embedment length. Anchorage to concrete is designed under ACI 318, Chapter 17.

Raven isn't tied to one manufacturer. We source from whichever has the fastest delivery, so every project starts by matching the foundation design to that manufacturer's anchor rod plan and reactions. See our PEMB explainer for how the rest of the building fits together.

Rod grades you'll see on the plans

Most PEMB foundation plans call for rods to ASTM F1554, the standard specification for anchor bolts. It has three grades, named for minimum yield strength:

• Grade 36: 36 ksi, color-coded blue on the projecting end
• Grade 55: 55 ksi, color-coded yellow
• Grade 105: 105 ksi, color-coded red

The color code is required unless permanent grade marking is specified instead, so an inspector can check the grade in the field. Use the grade, diameter and embedment the engineer specifies, not whatever is on the shelf.

How close is close enough?

Base plate holes are oversized to give some room, but not much. The American Institute of Steel Construction's Code of Standard Practice (AISC 303-22, section 7.5.1) sets these tolerances for rods set in concrete:

• Height: the top of each rod within plus or minus 1/2 inch of the specified elevation
• 3/4 and 7/8 inch rods: each rod within 1/4 inch horizontally of its specified position
• 1, 1-1/4 and 1-1/2 inch rods: within 3/8 inch
• 1-3/4, 2 and 2-1/2 inch rods: within 1/2 inch
• Square to the bearing surface: unless the contract says otherwise, rods are set with their axis perpendicular to the theoretical bearing surface

The concrete industry's tolerance standard, ACI 117, uses the same per-rod numbers. AISC also puts the as-built survey on the party setting the rods: they check that every rod meets these tolerances before the steel arrives, and get the engineer's approval if a fix is needed.

The holes give a little slack. AISC's recommended oversized hole for a 3/4 inch rod is 1-5/16 inch, for example, per the American Society of Concrete Contractors (ASCC). ASCC also quotes AISC's Structural Steel Educational Council: rods misplaced up to about 1/2 inch can usually still be handled by the oversized holes, and beyond that, corrective work is required.

How we set them on a Spokane-area pour

• Template every group: rods are held in a plywood or steel template that matches the manufacturer's anchor rod plan, braced so the pour can't push them around
• Check before the truck shows up: we measure bay spacing and building width, diagonals for square, and rod projection against the plan
• Hairpins and tie rods: placed per the foundation drawings where the frame thrust calls for them
• Footing depth: column footings go below the frost line, 24 inches across most of Spokane County and the City of Spokane. See our frost depth guide
• Snow and wind: the reactions the foundation is designed for come from your parcel's loads. See our Spokane County snow load guide
• Protect the threads: tape or sleeves keep concrete off the threads so the nuts run on cleanly

Inspections Washington's code calls for

Washington builds to the 2021 International Building Code (IBC) with state amendments. Two sections matter for anchor bolts:

• Footing and foundation inspection (IBC 110.3.1): made after the footing excavations are complete and any required reinforcing steel is in place, before the concrete goes in
• Special inspection (IBC Table 1705.3): "inspect anchors cast in concrete" is listed as a periodic special inspection item, and adhesive anchors drilled into hardened concrete and loaded in sustained tension in horizontal or upward orientations need continuous special inspection

IBC section 1705.3 exempts some foundations from concrete special inspection, including isolated spread footings of buildings three stories or less that sit fully on earth or rock, so whether a special inspector is needed depends on the engineer's design and the building official. Your permit plans will say. Our permit and lead time guide covers how the paperwork fits the schedule.

When a bolt ends up in the wrong place

It happens, which is why the rods get checked before the steel is delivered. Great Western Buildings, a PEMB supplier, describes the usual options:

• About 1/8 inch off: usually manageable
• Up to about 1/4 inch: workable, but more inconvenient
• About 1/8 to 1/2 inch: the most common fix is reaming a slot in the base plate, which should be reviewed before anyone cuts steel
• Off by inches or outside the plate: the rod is unusable, and new anchors are typically drilled and epoxied in

Any field fix should go through the engineer of record, as AISC section 7.5.4 says, and post-installed adhesive anchors bring their own special inspection requirements under IBC Table 1705.3. The cheapest fix is a correct template and a tape measure before the pour.

What it costs

Raven's current installed price for a PEMB metal building is about $60 to $75 per square foot. Electrical, plumbing and utility hookups are extra. The foundation design depends on your building's reactions and site, so we quote it with your building. More on how the pieces add up in our kit vs. installed guide.

Get a PEMB and foundation quote

We pour the footings and set the anchor rods with our own concrete crew, then put the building on them, so there's no finger-pointing between a concrete sub and a steel erector. Call 509-350-2016 or request a free quote with your building size, intended use and address or parcel number.

Sources

• PEMB pricing: Raven Buildings' current rates
• MBMA, Common Industry Practices, 2024 Edition (PDF)
• Ceco Building Systems, Metal Buildings Engineer FAQ
• AISC, Toolbox Talk: Installation of Anchor Rods, AISC 303-22 Section 7.5 (PDF)
• ASCC Position Statement 14: Anchor Bolt Tolerances (PDF)
• Portland Bolt, ASTM F1554 specification
• UpCodes, IBC Table 1705.3 Required Special Inspections of Concrete Construction
• ICC, 2021 IBC Chapter 17: Special Inspections and Tests (Section 1705.3)
• ICC, 2021 IBC Chapter 1: Scope and Administration (Section 110.3.1)
• Great Western Buildings, Anchor Bolt Troubleshooting in PEMB Installs