Footing Rebar Details and Layout Drawings

A rebar footing detail is a section through the footing that shows its size, the bars in each direction, their spacing, the concrete cover and any dowels into the wall or column above. It works together with a footing plan (where each footing is) and usually a footing schedule (what goes in each type). Read all three together and you have the full layout: how many bars, how long, which way they run and where they stop.

This guide walks through those drawings the way a placing crew or estimator reads them. If your question is which bar size a house footing needs, start with rebar for footings in Ontario instead.

The three drawings that define footing steel

Footing reinforcement is rarely shown in one place. On most structural sets it is split across three pieces:

1. The foundation plan. Shows every footing in plan, tied to grid lines, with a mark such as F1, F2 or SF (strip footing). Strip footings run under walls; pad footings sit under columns and piers.
2. The footing schedule. A table that lists each mark with its plan size, thickness and reinforcement. Pad footings with the same size and steel share a mark.
3. Typical sections and details. Cuts through strip footings, pads, steps, corners and thickened areas, showing where the bars sit and how they connect to the wall or pier above.

General notes tie it together. They state the concrete strength, rebar grade, cover, lap lengths or splice class, and often say "typical unless noted otherwise". RSIC (Reinforcing Steel Institute of Canada) guidance to designers asks that "typical" and "similar" be used only where they strictly apply, because a detailer will reproduce a typical detail everywhere it is referenced.

On a house, the same information may be on one sheet, or a single typical section on the permit drawings. Plain strip footings sized under Part 9 of the 2024 Ontario Building Code have no rebar requirement, so many house footings have no reinforcement detail at all. Our guide on whether footings need rebar covers when they do.

Reading the footing schedule

A footing schedule might look like this (an example only, not a design):

How to read each callout:

• 15M @ 300 BEW means 15M bars at 300 mm centre to centre, bottom each way: one layer in each direction near the bottom.
• 7-20M LW means seven 20M bars running the long way. SW is the short way. In rectangular footings the two directions often get different steel.
• TEW means top each way, a second mat near the top of thick or heavily loaded footings.
• 3-15M CONT means three continuous 15M bars along a strip footing, lapped where they join.

Spacing on drawings is always centre to centre. A count ("7-20M") and a spacing ("20M @ 250") are two ways to say the same thing; the detailer converts one to the other using the footing width less cover. If both are given and they disagree, ask before ordering.

Reading a typical footing section

The section is where the layout becomes three-dimensional. A typical strip footing section shows:

• Footing width and depth, often with the wall centred or offset on top.
• Longitudinal bars, drawn as dots because they run into the page, with their size and count.
• Transverse bars, drawn as a line across the footing, with size and spacing, in wider footings that need them.
• Cover dimensions. CSA A23.1 calls for 75 mm of cover where concrete is cast against and permanently exposed to earth, which is why the bottom bars sit well above the soil.
• Dowels. Bars bent with a foot at the bottom of the footing that rise into the wall, with the projection or lap length shown.
• Keys or shear keys, if the design uses a recess at the top of the footing to lock in the wall.

A pad footing detail adds the plan view of the mat and the dowels for the column or pier. Where the pier or column is offset from the footing centre, the dimension from grid line to dowel group is the one to check first, because dowels in the wrong place are the hardest error to fix after the pour.

When the drawings do not give bar lengths, RSIC standard practice is to detail footing bars as straight bars stopping 75 mm from each face. Footing dowels, unless noted otherwise, are the same size and spacing as the vertical bars they connect to. Both are defaults, and anything shown on the drawings overrides them.

Layout details that trip people up

A few footing conditions cause most of the questions on site:

• Corners and intersections. Continuous bars need corner bars or bent ends to stay continuous around the building. The arrangements are shown in our post on footing rebar laps and corner bars.
• Step footings. Where the footing steps down a slope, the detail shows how bars pass through each step, either as bent bars or with laps. For Part 9 houses, Article 9.15.3.9 of the 2024 OBC limits each step to a 600 mm rise with at least 600 mm horizontally between risers.
• Laps. Footing bars longer than a stock bar are lapped. The drawings give a lap length or a splice class; stagger and position follow the notes.
• Footings at different depths. Where footings must be carried to different depths, RSIC notes the designer may use a pier or cap on top of the footing to bring the column start to one level, connected with dowels. Each piece gets its own steel.
• Openings and penetrations. Pipe sleeves through a footing should be located on the drawings, and the designer may add bars around them. If a sleeve is not shown, ask before cutting or moving bars.
• Thickened areas. Where a footing gets deeper under a point load or a chimney, the section usually shows extra bottom bars. Check that the bar lengths match the thickened zone, not the whole footing.

From detail to bar list to placing

The design drawings tell you what the footing needs. They do not tell the shop how many pieces of each length and shape to cut. That is the detailer's job: the details become a placing drawing that marks every bar, and a bar list that gives each mark's size, quantity, length and bend shape. Our post on foundation rebar shop drawings explains what those look like for footings and walls.

On site, the crew places from the placing drawing, not the design detail:

• Snap the footing lines and grid lines first, so dowels and corner bars land in the right place.
• Set bars on supports sized for the bottom cover, never on the soil.
• Place bars at the spacing shown, starting and ending within the cover at each face.
• Tie dowels so they stay plumb and at the right projection during the pour.

Our guide on how to lay and tie rebar in footings covers the placing sequence

What to check before you order footing steel

Before footing bars are cut, run through this list against the drawings:

• Every footing mark on the plan appears in the schedule, and the counts match.
• Bar sizes, spacings and directions (LW, SW, BEW, TEW) are read the same way by everyone.
• Cover is stated, and the bar lengths allow for it.
• Dowel size, spacing, projection and position match the wall, column or pier design.
• Step locations and elevations are known. If founding levels may change in the field, hold back the step bars until they are confirmed.
• Corner, intersection and lap details are clear.
• Any revisions since the last issue have been picked up.

Structural footing design belongs to a designer or engineer, and most new foundations need a building permit. If a detail is unclear or missing, put the question to the designer in writing before anything is cut.

Get your footing details turned into a bar list

Procut provides rebar estimates and detailing from your structural drawings, then cuts, bends, tags and bundles the footing steel so it is ready to place, with delivery across the GTA and Ontario. Take-offs and quotes are free.

Send your foundation drawings for a bar list and price, or see our services for detailing, fabrication, delivery and installation.