Inspecting Your Wood Deck

In Ontario if your wood deck is over 23 5/8 inches above grade (600 mm) , over 108 sq ft (10 m2) in size or is attached to your house you require a Building Permit from your local Building Department.  Many municipalities have a webpage which details everything you need when applying for your Deck Building permit.  View City of Orillia Requirements

Common Defects Found During Deck Inspection

Loose or Nailed Ledge Board Attachment

Older homes may have deck attached to a ledger board that is only nailed onto home.  Modern decks should be securely attached to the house structure with a properly flashed ledger. A ledger is a horizontal board attached to theInspecting Wood Deck in Orillia home that supports the deck framing. One of the most common attachment defects is a ledger attached to the home with nails or screws. Nails pull loose over time, which can cause the deck to detach from the home. Screws have less sideways or sheer strength than nails and overloading can cause them to break. Modern standards call for carriage bolts or lag screws into the house framing. These fasteners provide shear strength and resist pulling out. They should be attached alternately near the top and bottom of the ledger, and spaced closer for longer joist spans.

Flashing for Ledger Board

To prevent water from seeping behind and rotting the ledger, there should be a continuous length of metal flashing running along the ledger. The flashing must extend up behind the house siding and overlap the top edge of the ledger. If the ledger on your deck has no flashing, you must install one, which is a relatively easy job if the decking runs parallel to the house. 

Stairs, Guards and Required Handrails

Safety is critical around stairways, and defects are often found with exterior stairways, which may not be as well protected as indoor stairways. Open risers can allow a person foot to slide under. Less obvious, the risers supporting the treads may be weakly attached to the deck. Stairs often have one or risers that are different enough from others to be a tripping hazard.

Guards and handrails are important safety features that can prevent falls. Decks and stairs that are thirty inches or more above the surrounding grade need a sturdy guard that rises far enough above the walking surface to prevent a fall. Commonly, guards are too low, and as decks age, they grow too weak to prevent falls. Graspable handrails are often lacking on short deck stairways, especially if they are not home entrances, but all flights with four or more risers need one.


Ontario Stairs Table















Guards and Handrails

A guard is required on the stair where the stairs are higher than 23 5/8 inches. Guard pickets cannot be spaced more than 3 15/16 inches apart. No horizontal members are installed to the guard between 5 1/2 inches and 35 7/16 inches that could facilitate climbing. Interior stairs with 3 or more steps and exterior stairs that have 4 or more steps require a handrail. Handrails must be located at a height between 34 1/16 inches and 42 1/16 inches

Wood Rot

Wood rot is a common problem with badly maintained and unprotected decks. Not only is rot unattractive, it can end up undermining the integrity of your deck. If the deck is sealed but still shows signs of rot, it is critical to check the spot after the next rainstorm to try and discover where the water is coming from. In a majority of cases, you will discover a problem with a fixture or a gutter that is funneling water onto a specific area of the deck. Rot is particularly common around stairs and handrails, where it is more difficult to have sealed.

Lack of Building Permit

Finding a deck that is supported on Deck Blocks or is missing the required Guards are immediate “Red Flags” that the deck was constructed without a Building Permit.  If you buy a home that you know has a illegally constructed deck then the responsibility for that deck falls on you.  If you bought a house and were unaware that the deck was not built to the Ontario Building Code requirements then you may have a claim to have deck properly constructed with your Title Insurance Company.