Deck Installations & Inspections

Deck Installation can be disastrous if not built properly.

Every spring homeowners start improvement projects on the exterior of their home.  One of the most popular projects is to build or increase the size of your deck.  A well built deck can greatly enhance your enjoyment of the outdoors and also increase the size of your living area, weather permitting.

The very first item you may need is a building permit.  You will require a building permit if your deck is attached to your house, the area is greater and 107 sq ft or the deck is adjacent to an entrance or exit.  You local building department will typically make 3 inspections which are: Deck footing inspection; Framing inspection and Final Inspection.

deck collapse by angus home inspectorAttaching the deck to your house.  Typically a ledger board is used to attach deck to the home.  The most common reason for deck collapses is improper attachment at the house.  That’s what happened with the deck pictured above.  If the deck is supported by the house, it should be attached with bolts, lag screws, SDS screws, or some other similar method.  Also flashing is required above the ledger board to prevent water from entering your home or rotting wood behind the ledger board.  Pay attention to every detail when applying the ledger board. The ledger board and the footings are the two most important and sometimes complicated components of deck construction.  One study on deck collapse noted that the most common cause of deck collapse was failure of the ledger board.

If your home has engineered wood floor trusses then you will most likely require a standard detail provided by a truss designer as you cannot attach anything to the trusses.   In this situation it would probably be easier just to build a free standing deck and avoid the extra cost of design.

One common mistake home owners make is not extending their concrete piers above grade enough to allow for future landscaping.  You are required to extend concrete piers  a minimum of 5 7/8 inches above grade.  This protects your wood from moisture and early failure due to rotting.  Another requirement of some municipalities is to have to bottom of your post hole belled out for greater stability.


Joist Hanger Nail SizeIf you are using joist hangers on your deck it is important to read the installation instructions which will specify exactly what type of fastener is to be used.  Screws are a poor substitute as they do not have the shear strength of nails.  Even nails called joist hanger nails maybe improper for use with your joist hanger.

Guards are required when you have a difference in elevation greater than 23 5/8 inches.  A maximum spacing between guards is 4 inches with 800 mm of unclimbable area vertically.  Attachment to post for rail connections require a minimum of 20 gauge framing anchors.  Plastic clips are not permitted to be used in Barrie ON.  Check with your local building department before purchasing custom deck products. If the product has not been approved you may not be able to use them in the construction of your deck.

Stairs stringers have to be constructed of a minimum 2X10 and spaced no further than 2 feet 11 inches.  Stairs risers have to be equal in height with a max of 7 7/8 inches and a min of 4 7/8 inches.  Stairs with more than 3 risers require a handrail to be installed.  Tread depth permitted is a maximum depth of 14 inches and a minimum depth of 9 1/4 inches.

For more information on Deck Building Requirements visit or call your local building department to find out their exact requirements.  For more handy tips visit Angus Home Inspections


For the unfortunate people who reside in an area controlled by a Conservation Authority,  they be required to get permits and supply drawings etc before permission is granted, and from my experience of dealing with homeowners seeking Conservation Approval,  they all say it is not a pleasant experience.