Steel Base Plate Cost: What Drives the Price

A steel base plate has no single price because it is a fabricated part, not a stock item. Its cost is built from the plate material (priced by weight), the cutting, the anchor rod holes, any welding to the column, the finish and the quantity. For one or two small base plates, the shop time to set up, cut and drill is usually a bigger share of the price than the steel itself, so a 300 x 300 plate does not cost much less than a 250 x 250 plate at the same thickness.

This guide explains what you are paying for, shows how much common base plates weigh, and lists what to send so a quote comes back accurate the first time. We don't publish prices; for a number on your plates, send us the detail.

What you are actually buying

"Base plate" can mean three different things on a quote, and the price changes a lot between them:

• A loose plate. The plate is cut to size and drilled, and someone else welds it to the column or uses it as a bearing plate.
• A plate welded to a post or column. The fabricator cuts and drills the plate, then welds it to the HSS post or W-shape column under shop welding procedures. This is the usual case for basement posts and building columns.
• A complete base. The plate on the column, plus the anchor rods, nuts and plate washers, sometimes with a levelling plate or shim pack. Anchor rods are often supplied separately to the concrete contractor so they can be cast into the footing before the steel arrives.

When you compare quotes, check which of these each supplier priced. A low number for a loose plate isn't comparable with a price for a plate welded to a post.

How much does a base plate weigh?

Material is the one part of the price that does follow weight. Carbon steel plate weighs 7.85 kg per square metre for every millimetre of thickness, so weight is easy to work out:

length (m) x width (m) x thickness (mm) x 7.85 = weight in kg

Here is what the two most searched sizes weigh at common plate thicknesses. Plate is widely sold in fractional-inch thicknesses, so the metric value is the converted thickness.

Weights are before holes, which remove a little steel. A 300 x 300 plate is 44 percent larger in area than a 250 x 250 plate, so it uses 44 percent more steel at the same thickness. That difference matters on a large order of identical plates. On a single plate, it is a small part of the total.

Why "base plate price per kg" can mislead

The raw plate is bought by the tonne, and plate prices are often discussed per kg. A finished base plate is different. The cutting, drilling, deburring, welding and painting take roughly the same time on a 6 kg plate as on a 9 kg plate. Divide the finished price by the weight and small plates always look expensive per kg, because the fixed labour is spread over very little steel. Our guide to steel plate prices in Canada explains how raw plate itself is priced.

What drives the price of a base plate

Thickness and size

Thickness has two effects. More steel costs more, and thicker plate takes longer to cut and drill. Very thick plates can also limit which cutting method suits the job. The size and thickness come from the engineer's design, which we walk through in our column base plate design example. Don't substitute a thinner or smaller plate to save money: it is a structural change that needs the designer's approval.

Grade

Structural plate in Canada is commonly specified to CSA G40.21 grades such as 300W or 350W, and US-origin drawings often show ASTM A36 or A572 Grade 50. Most base plates use common grades. A less common grade, or a requirement for mill test certificates on every piece, can add sourcing time.

Holes and slots

Every anchor rod hole is an operation. A four-hole plate costs more to make than a plain bearing plate, and slotted or oversized holes take more work than round holes. Hole size and position must match the anchor rods cast into the concrete, so accuracy matters more than speed.

Welding to the column

Welding the plate to the post or column is often the largest labour item. Weld size, whether the weld runs all around, and whether stiffeners or gussets are added between the column and plate all change the shop time. Gussets need extra cutting, fitting and welding on both sides, which is why a thicker plate without stiffeners is sometimes the cheaper detail. That's the engineer's call.

Finish

Plain mill finish, shop primer and a full paint system are different price points. Exterior plates and plates in damp basements may need a more durable coating. We can prime or galvanize plates to suit the job.

Quantity and repetition

This is the biggest lever on price per plate. Ten identical plates share one setup, one program and one hole layout. Ten different plates are ten small jobs. On a building with many columns, keeping base plates to a few standard types makes a noticeable difference.

The installed cost of a base plate

The plate is only one line in the cost of a column base on site. The installed cost also includes:

• Anchor rods cast into the footing or pier, with their nuts and washers, or drilled-in anchors in existing concrete where the engineer allows them.
• The footing itself. A new footing under a basement post usually costs far more than the post and plate.
• Setting and levelling. Columns are set on levelling nuts, shims or a setting plate, then grouted with non-shrink grout.
• Temporary support and labour, especially in renovations where the post replaces an existing support.
• Permits and inspections where the work is structural.

For basement posts in houses, the 2024 Ontario Building Code requires steel columns to have end bearing plates at least 100 mm x 100 mm x 6.35 mm (Article 9.17.3.2), and the column must sit on a proper footing. Our guide to lally column and steel post cost covers the whole basement post job, and embedding steel posts vs base plates explains when a plate is the right detail.

Ways to keep base plate cost down

• Order posts and plates together. One fabricator cutting, drilling and welding in one setup avoids double handling and mismatched holes.
• Standardize where the design allows. Ask the engineer whether several columns can share one plate type and hole pattern.
• Use available thicknesses. If the drawing shows a metric thickness that isn't commonly stocked, ask the designer early whether the nearest stocked thickness is acceptable. Don't change it on your own.
• Avoid unneeded features. Bevels, chamfered corners and stiffeners each add time. Keep them where the design needs them.
• Match the finish to the exposure. A high-end coating on a plate that will be cast into a basement slab is money spent where nobody sees it.
• Send complete information once. Revisions after cutting are the most expensive change of all.

What to send for an accurate base plate quote

A base plate quote is only as good as the detail behind it. Include:

• Plate length, width and thickness, and the steel grade
• Hole diameter, number of holes and their positions (or the anchor rod layout)
• Whether the plate is loose or welded to a post, and the post size and length if we are supplying it
• Weld size and type from the drawings, and any stiffeners
• Finish requirements
• Quantity of each plate type
• Delivery address and timing

A drawing, sketch or DXF with dimensions is ideal. Our guide to ordering steel plate cut to size covers drawing and file formats in more detail.

Get a base plate price from Procut

We cut and drill base plates, cap plates and connection plates to your details, and we supply HSS and steel posts with base and cap plates welded on, with shop welding certified by the Canadian Welding Bureau. Send your base plate schedule, post sizes or drawings through our quote form and we'll price the plates, posts and connections together, with delivery across the GTA and Ontario. See our steel products for the rest of what we make.