Footing to wall dowels are short bars cast into the footing that stick up to lap with the wall's vertical reinforcement. Unless the drawings say otherwise, they are the same size and spacing as the wall verticals, hooked into the footing so they develop in a shallow depth, and long enough above the footing to make a full lap with the wall bars. Whether a wall needs them at all depends on the wall type: plain poured walls built to the Ontario Building Code's Part 9 tables do not, while flat ICF walls, reinforced block walls and engineered walls often do.
This post covers the footing to wall joint specifically. For dowel length calculations across 10M to 35M, see how long rebar dowels should be.
When a wall needs dowels into the footing
The joint between a footing and a wall is a cold joint: two pours, days apart. Dowels carry force across it, usually to stop the base of the wall sliding or rotating under soil pressure and to make the wall's vertical steel continuous down into the footing.
| Wall type | Footing dowels | Where the rule comes from |
|---|---|---|
| Plain poured concrete foundation wall within Part 9 | Not required by the code | 2024 OBC, Table 9.15.4.2.-A |
| Flat ICF foundation wall | One of three ways to give the wall lateral support at the bottom | 2024 OBC, Article 9.15.4.4 |
| Reinforced concrete block foundation wall | Continuous verticals embedded at least 50 mm into the footing when the floor slab does not support the wall base | 2024 OBC, Sentence 9.15.4.2.(4) |
| Engineered (designed) wall | Set by the design | CSA A23.3 |
Flat ICF walls
Part 9 requires flat ICF foundation walls to be laterally supported at the bottom. Article 9.15.4.4 accepts three ways of doing that: backfill no higher than 1.2 m, a shear key at the footing combined with support from the ground floor framing at the top, or dowels to the footing of at least 15M at not more than 1.2 m on centre, or 10M at not more than 600 mm on centre. If your ICF drawings show dowels, those are the minimums they are working from.
Reinforced block walls
Where Table 9.15.4.2.-B calls for reinforced block, the vertical bars must be continuous from the top of the footing to the top of the wall, placed at corners, wall ends, intersections, changes in wall height, the jambs of every opening and movement joints. When the walls are laterally supported at the top and the floor slab does not support the base, the verticals need at least 50 mm of embedment into the footing. Because those bars have to land inside grouted block cores, dowels for block walls must line up with the block layout, not just a spacing on a plan.
Engineered walls
When a wall is designed under CSA A23.3, the reinforcement crossing the footing joint must transfer any tension and any compression the concrete cannot carry in bearing. A23.3 also sets a floor (Clause 15.9.2 in the 2004 edition): for cast-in-place walls, the steel across the interface must be at least the minimum vertical wall reinforcement, and for columns and pedestals at least 0.5% of the gross area. Our post on foundation wall rebar in Ontario covers the wall steel itself.
Dowel size and spacing
Size. RSIC standard practice is that footing dowels are the same size and spacing as the vertical bars in the element above, unless the drawings note otherwise. CSA A23.3 adds that dowels cannot be more than one bar size larger than the vertical bars they lap with. So a wall with 15M verticals gets 15M dowels, or 20M at most if the engineer wants them heavier.
Spacing. Matching the vertical spacing keeps every wall bar lapped with a dowel. A few layout points:
- Start and end dowels close to wall corners and ends, and add dowels at wall intersections and either side of openings where the wall verticals are concentrated.
- Two-layer walls need two lines of dowels, one for each face of vertical steel.
- Position across the footing matters. Dowels should sit where the wall bars will be, which for ICF walls in Part 9 means the inside half of the wall with at least 30 mm of cover from the inside face.
- Block walls need the dowels at the reinforced core locations, so set the dowel layout from the block coursing plan.
Embedment and projection
A footing dowel has two working lengths.
Into the footing. The dowel needs enough embedment to develop the bar. A straight 15M dowel in 30 MPa concrete needs about 430 mm under the CSA A23.3 simplified method, which is often more than a house footing is deep once bottom cover is taken off. That is why footing dowels are normally hooked and set on the bottom mat. A standard hook develops a 15M Grade 400 bar in about 300 mm in 30 MPa concrete, before modification factors. The footing still has to be deep enough for the hook plus the bottom cover, which is 75 mm for concrete cast against earth under CSA A23.1.
Above the footing. The projection laps with the wall verticals. For engineered walls that is a CSA A23.3 lap, about 550 mm for a 15M Class B lap in 30 MPa concrete under the simplified method. For flat ICF walls in Part 9, the OBC sets fixed laps of 450 mm for 10M and 650 mm for 15M (Article 9.3.1.1).
The hook direction is shown on the details. Whichever way it turns, the hook has to stay inside the footing with full cover on every side. Our post on bent and hooked rebar dowels covers the shapes.
Setting dowels before the pour
Dowels are only as good as their position. The common methods:
- Tied to the footing steel. Hooked dowels are tied to the bottom bars at the right spacing and held upright with a top bar or bracing.
- Hung from a template. A board or bar across the forms, marked or drilled at the dowel spacing, holds the dowels at the right line and height while the concrete is placed.
- Checked before the pour. Spacing, line, projection height and cover should be checked against the drawings while it is still easy to fix.
Wet-setting means pushing dowels into the footing concrete right after it is placed. It is a common shortcut, but the bars often end up off line, short of their embedment or without proper consolidation around them, and the hook cannot be placed properly. Unless your engineer approves it, set dowels before the pour.
If dowels are missed altogether, they can sometimes be drilled and set in adhesive later, but that is a design change the engineer has to approve, with embedment and edge distance set from the adhesive's data. Our guide on how to dowel rebar into existing concrete explains the process.
Ordering footing dowels
Dowels are a high count, low weight item, and they are easy to undercount. For a 44 m perimeter wall with a single line of 15M verticals at 400 mm, the straight runs alone need about 110 dowels, before corners, intersections, openings and any second face. On the bar list:
- Show the full shape: hook leg, embedment and projection, not just the length into the footing.
- Separate marks for walls of different heights or bar sizes, and for dowels at steps in the footing, which may need different projections.
- Match the wall lap. If the wall verticals are changed after the dowels are ordered, the projection may no longer give a full lap.
- Tag by location so the right dowels end up on the right wall.
We supply fabricated dowels bent and tagged to your marks, with the footing and wall steel on the same order, delivered across the GTA and Ontario. Send us your foundation drawings for a free take-off and quote, or see our rebar products.
Frequently asked questions
What size and spacing should footing dowels be?
Unless the drawings say otherwise, RSIC standard practice makes footing dowels the same size and spacing as the vertical bars in the wall above. CSA A23.3 also limits dowels to no more than one bar size larger than the wall verticals.
Do poured concrete foundation walls need dowels into the footing?
Not under Part 9 of the Ontario Building Code for plain poured walls that meet its thickness tables. Flat ICF walls can use dowels as one of three ways to be laterally supported at the bottom, and engineered walls get dowels from the design.
How deep do footing dowels go into the footing?
Deep enough to develop the bar, which is usually done with a standard hook resting on the bottom mat. Under CSA A23.3, a hooked 15M Grade 400 dowel in 30 MPa concrete needs about 300 mm of embedment before modification factors, plus bottom cover below the hook.
Can you push dowels into wet concrete after the footing is poured?
Only if the engineer approves it. Dowels pushed into fresh concrete can end up out of position, short of their embedment and poorly consolidated around. The normal practice is to tie or template dowels in place before the pour.
