Residential Deck Guide

Construction Drawings

The homeowner (person on title) is permitted to design the deck. If the homeowner is not preparing the design, it must be designed by a qualified designer with a minimum qualification of BCIN House. This requirement is set by The Ministry of Municipal Affairs and Housing. A form called Schedule 1: Designer Information, must be completed.

Deck Construction

Anyone is permitted to construct the deck once a building permit has been obtained. It is the responsibility of the homeowner to ensure that:  

• a building permit has been issued
• the work complies with the Ontario Building Code
• the required building inspections have been scheduled
• the building permit is closed once construction has been deemed complete by the building inspector.

When making a building permit application for a deck or platform, the following drawings are required:

1. Site plan
2. Foundation and framing plan
3. Cross-section drawing (including stair and guard details)

The information in the guide will explain these items in further detail.

The homeowner is responsible for the project whether or not they have hired a contractor to complete the work.

Deck Reconstruction

If you are reconstructing or repairing the same size deck a building permit is required. If the deck you are repairing or replacing was constructed prior to the current Ontario Building Code, there may be new requirements to ensure safety requirements have been achieved with today’s building materials and methods.

Constructing, repairing, or reconstructing without the authority of a building permit may result in extra fees for Building Code Act Orders or extra fees for the building permit application. It may also result in extra costs for additional materials, or for a professional engineer’s design (P.Eng. review) being required to bring the deck into compliance with the Ontario Building Code (OBC).

Determining the Deck Size Permitted

Contact the Building Services Division. Staff will review the zoning of your property and  provide regulations based on the by-law requirements for your property (setbacks to lot lines, permitted height of deck, etc.).

Construction Materials

Considering what building materials and construction methods that you intend on using to construct your deck during the early stages of planning will aid in eliminating delays in obtaining a building permit. It will also eliminate frustration on site during construction.

If you are unsure about any building materials or construction practices, Building Services staff will aid you in determining OBC compliance.

Considerations at this stage include:

• How high will the deck be from the ground.
• What type of foundation system will be used.
• Will it be connected to the house? If so, will it be connected to the foundation or rim board.
• What type of decking will be used.
• What type and style of guard (railing) will be used.
• Will the deck have stairs.

Hot Tub on a Deck

If you are planning to place a hot tub on the proposed deck, it will require a Professional Engineer’s review due to the increased weight introduced by the hot tub. A building permit is required to retrofit an existing deck to accommodate a new hot tub. A permit from the Electrical Safety Authority (ESA) will be required for the installation of the electrical service for the hot tub. The ESA may be contacted at 1-877-372-7233. A hot tub may also need a pool enclosure permit. Contact the By-law Enforcement Office at 705-742-7777 ext.1651 for more information.

Other Deck Considerations

When designing you deck, also consider the following.

• The location of overhead wires.
• The location of hydro and gas meters.
• Will the proposed decks obstruct any windows or doors, specifically any basement windows used for egress?
• If new windows or doors are proposed in relation to the deck, they must be indicated on the drawings with location, size and framing (lintel).

Building Permit Application Requirements

Site Plan

The Site Plan is a requirement that must accompany building permit applications to show the proposed construction and or demolition on the property. The plan should be drawn to an appropriate scale. A copy of your location survey plan may be used as a basis to prepare a site sketch, however, only the surveyor may alter the registered copy of the survey for submission with your application. If you are not capable of preparing an accurate site plan, you may hire someone to prepare it for you.  

As the property owner, you are responsible for the accuracy of the information provided to the Building Services Division. If a location survey prepared by an Ontario Land Surveyor is not provided, you may be required to provide one showing the limits of your property, the structures, and setbacks to the lot lines.

See the Sample Site Plan for more information.

Foundation and Framing Plan

The Foundation/Framing Plan explains the structural components of the proposed construction in a  “bird’s eye view”. This drawing clearly indicates the distance between foundation and post elements  and the length and size of framing elements being used (beam length, joist length and sizes) – refer to the following section, “Framing Design and Materials”. The plan must include the following information:

Deck Plan View (sample)

Footing size: Clear span of beam (9’-6”) and half of the clear span of the supported joist plus the joist cantilever (half of 9’-8” which is 4’-10” + joist cantilever 1’-4” = 6’-2”). Refer to OBC Table 

Cross-Section Plan

This clearly indicates the general appearance of the deck and how the  proposed components will be constructed. This includes information pertaining to the guard if one is  required. The drawing must include the following items:

• Type of footing being used and the proposed depth
• Height of deck walking surface above grade
• Height of guard above walking surface
• Any details related to proposed stairs
• Guard construction (type proposed and details)
• Ledger connection (deck to house)
• Lateral bracing, if required

More details on these items are provided below.

Deck Cross Section (sample)

Foundation Systems

Common foundation types:

• Helical Pile - this is an engineered system. The building permit application submission must include the engineered design from a qualified individual.
• Pre-engineered bell shaped foundation forms - examples of these are footing tubes, Bigfoot.
• Construction tubes - example is sonotube
• Concrete block
• Pre-engineered bell-shaped foundation systems such as Bigfoot or Footing Tube are becoming increasingly popular. These are proprietary systems and must be installed as per the manufacturer’s engineering, as they have determined the allowable loads and/or spacing requirements.

Unless designed by a professional engineer, any footings that are to be located within 1.5m (5'-0") of an existing building must extend to native bearing soil and the same footing depth as the foundation system it is adjacent to.

Deck Angle Of Repose (sample)

The footing must always bear on undisturbed soil. Disturbed soil is material used for backfill and may compact over time causing the structure to shift.

Foundations must extend to a minimum of 1.2m (4’) below the finished grade.  This is to prevent frost heave which may cause the deck foundation to fail by pushing it up during the winter and allowing it to settle during the spring. If the deck is connected to the house structure, it may also cause the structure to fail over time.

After a foundation has been installed and inspected, it must be backfilled.

New foundations must not interfere with the existing foundation drainage systems.

Floating Decks

These decks are constructed without a full depth foundation system (no frost protection). Floating decks are permitted when the proposed deck meets all the following conditions:

• The deck is less than 600 mm (23-5/8") in height,
• The deck is not attached to any structure,
• The deck is not supporting a roof, and
• The area of the deck is not more than 55 m² (592 ft²).

A building permit is still required if you are intending on constructing a floating deck. 

Deck Components

Framing Design and Materials

A deck is typically constructed using columns, beams, joists, and decking. The section of the OBC pertaining to decks is very specific as to what materials are permitted to be used, and how they are permitted to be used. Any proposed deviations from these may result in the requirement of a Part 4 Design by a Professional Engineer. If a proprietary material or product is proposed, it is required to have documentation indicating its compliance with the OBC. 

Columns (Posts): are the vertical members that transfer and carry the load from the beam system to the foundation system. Columns for decks are typically constructed of wood; but may also be steel, solid concrete, or concrete masonry.

• Wood columns must be the greater of 140mm x 140mm (5.5” x 5.5” and are commonly referred to as 6”x6”) or the width of the supported member (ex: 3-2x8 beam).
• Columns that are greater than 600mm (23 5/8”) in length are required to be laterally supported.

When beams are continuous over more than one span, joints are permitted at or within 150mm of the end quarter of the clear span, provided the joints are not those closest to the ends of the beam.

Beams are permitted to be fastened using nails that are a minimum of 89mm in length and spaced not more than 450mm apart. Nails are also required to be between 100mm to 150mm from the end of each piece.

Beams are also permitted to be fastened together with 12.7mm diameter bolts and must be equipped with washers.   Bolt spacing is a maximum of 1200mm. Bolts must also be located not more than 600mm from the ends of members. 

Joists:  Are the part of the flooring system that transfers the load of the decking to the beams. The spacing of the joists will often be determined based on the choice of decking and installation.

• Typically, joists are permitted to cantilever 400 mm (16”) if 2 x 8 is used, or 600 mm (24”) if the joist depth is 2 x 10 or greater.
• If your deck will require a guard (often referred to as a railing), the minimum joist depth permitted is 2 x 8. Refer to the SB-7 Guards for Residential Decks handout.

Ledger Board (Ledger Plate): is a 2 inch board that at a minimum matches the depth of the joist being used. It is fastened to the exterior wall of a building, usually to the foundation or through to the rim board of the floor system of the building.

P.Eng design required for:

• Engineered Wood Product rim board
• Rubble foundation or multiple wythes of masonry
• Through masonry veneer

Decking: The floor of the deck. It is often made of Spruce/Pine/Fir (SPF) species conventional lumber such as 2 x 6 or 2 x 8, but can also be constructed of Northern Species such as cedar, or a composite material. Decking is also permitted to be made of 5/4” thick material, which many lumber yards stock specifically for decking. The type of decking that you choose to use will determine what the permitted spacing of the joists will be. 

Determining Footing Sizes

Determining Beam Size

 The following table will help determine beam size required for the proposed spans of the deck.

 Remember that the typical maximum permitted beam cantilever is 1 foot.

Joist Size

The following table will assist in determining the minimum joist depth based on the size and spans selected.

Stairs

If the proposed deck design will be incorporating stairs and/or a ramp, the drawings must incorporate them into the design. It is important that the proposed design is reviewed to ensure the stairs are constructed in accordance with the OBC to prevent injury/accident to people that may be using them. Also ensure that the stairs are indicated on the site plan.

Stairs must include:

• Uniform rise and run (same height and tread depth for each for each step)
• A minimum width of 860mm (2'-10")
• A level landing or base at the top and the bottom of each run of stairs
• Adequate foundation and framing
• A handrail is required if there are more than 3 risers
• Requires a compliant guard system if the difference in elevation exceeds 600mm (23 5/8")
• If 5/4"or composite decking is used, the stringer spacing must match the joist spacing
• Depth of rectangular treads shall not be less than its run plus 25mm
• The vertical height between landings on stairs cannot exceed 3.7m (12'-11 1/2")

Stair Rise

Minimum 125 mm (4 7/8")

Maximum 200mm (7 7/8")

Stair Run

Minimum 255 mm (10 1/16")

Maximum 355 mm (14")

The base of the stringer is required to be supported and secured to a foundation. Depending on the number of risers, the necessary foundation for the stairs will vary. All stairs that are constructed must be supported and secured at the top and bottom. The top support is most easily achieved by using a mechanical hanger that is designed to support stairs. The bottom support can be done by notching a 2”x4” into the bottom stringer that is anchored to a concrete pad. 

The edge of a step, called a nosing, is required to be rounded or beveled between ¼” to ½” measured from the edge of the tread to help prevent tripping, especially in emergency situations. If the edges are covered with a resilient material, the rounding or beveling can be reduced to ⅛” (9.8.4.8.). Should you choose to do this, ensure that the resilient material is flush to the surface of the step so that the step is even (9.8.9.6.(0.1)).

Guards

A Guard is the component of a deck that is designed to prevent someone from falling off the walking surface. If you intend to construct a wooden guard, please visit the OBC SB-7 Guards for Residential Decks webpage for the requirements for installation.

If the guard you select is not listed in the SB-7 guidelines, the manufacturer’s installation  instructions or proprietary products stamped and signed by an engineer licensed in the province of  Ontario must be submitted. These details should be available where you intend to purchase the  product. Examples of this are pre-manufactured guards constructed out of glass or aluminum.