Decks, Balconies, and Porches

Deck Solid State Home Inspections

The exterior of our homes has a difficult job to do all year and protrusions to the exterior like decks, balconies, and porches become weak spots for potential problems. For home inspectors, decks, balconies, and porches can have some of the worst safety and structural deficiencies in a home inspection

Defining Decks, Balconies, and Porches (and Patios)

Decks, balconies, and porches share many common characteristics like flooring materials, guardrails, and structure however there are differences. As patios are often similar to decks, we included them below to avoid confusion:

  • Patios - Patios are flat surfaces, typically very close to the ground level that use the ground for structure. Examples include concrete pads and pavers or stones laid onto a prepared ground surface. 
  • Decks - Unlike patios, decks are built over the ground with structural elements. These structural elements could include tieing the structure of the deck to the home and/or dedicated structure for the deck. Decks may have stairs to access the ground level and often have a door leading into the home. Decks are very commonly build by amateurs which increases the deficiencies found by home inspectors
  • Balconies - Balconies are above the grade level of the property, often one or more elevations with a door access from the home. Balconies often have structural ties to the home and may have dedicated supports down to ground level. Balconies do not commonly have stairs to ground level. Balconies are most commonly built at the time of home construction.
  • Porches - Porches are commonly part if the front entrance to the home and have structure similar to decks. They will have stairs if needed so occupants and guests can reach the front door.


Wood is the most common structural material for decks, balconies, and porches on single family homes and wood framed low rise condo's. Concrete and steel materials are more common for high rise balconies. 

When the structure of the porch, balcony, or porch is tied to the accompanying home, the home becomes part of the structure. These connections can be done by cantilevering materials from the home, common with jut-out balconies, or by bolting the structures together at the floor connections. A common home deficiency found in home inspections is thet instead of washer, nuts, and bolts holding the structures together there are only nails or screws. Nails and screws do not meet the requirements for connecting these structures together.

Balconies, decks, and porches, and corresponding stairs may have their own structure separate from the main home. Good structure always starts with a good foundation. The foundations should protect the structure from movements in the soil like frost or water erosion, be solid enough to resist the movement of people and objects on the structure, and be able to carry the weight of snow, people, and building materials. 

Common structure will have wood or concrete vertical posts that rise from the foundations. These posts should then be attached mechanically with fasteners to beams which connect the vertical posts together. From the beams, joist hangers hold the joists which form the main platform floor. Another common home inspection deficiency with decks, balconies, and porches is missing mechanical fasteners to correctly hold all the structure together. Lastly, the deck of the floor will also form part of the structure. Wood slats or plywood decking are commonly used and they also increase the rigidity of the structure. 

Home inspectors need to look for appropriate use of materials and solid connections particularly on decks which are commonly built by amateurs. Common structural deficiencies include poor foundations, wood rot, over-spanned distances, incorrect connections, and excessive movement of the system.

Water Ingress

Water is the worst enemy of all structures but decks, porches, and balconies are particularly susceptible for two reasons. First, they create penetrations in the main home exterior that need to be correctly addressed. Second, they have large flat areas that need to manage water run off from rain and snow.

Home Exterior Flashing

The point where a balcony or deck protrudes from the main build structure a major concern for home inspectors. This area requires detailed flashing appropriate for each type of exterior surface to ensure the penetration does not introduce water to the main building, particularly in wind driven rains. Failures of balcony and deck flashings can lead to major expenses for home and condo owners and is part of the 'leaky condo' epidemic on the Canadian West Coast that is also spreading across North America. 

Surface Water Drainage

Flat floor surfaces need to have some type of drainage for water from rain and snow melt. Solutions can include a slight slopes to gutters or drains, or, gaps between floor boards for water to pass through. Gaps in floor boards can create hidden water problems if water falls onto horizontal surfaces of wood beams and posts. Designers of these floor systems need to consider water run off to maximize the life of the structure. 

Stairs and Handrails

Stairs are common on decks and porches and like any set of stairs, there are safety concerns. Structurally, stairs need to have correct support at the top, midspan, and base to prevent failure of the system. Additionally, all the steps should have an even height (rise) and tread size (run) and be consistent with normal construction standards. As steps can become slippery, particularly wood on north exposures, anti-skid strips are a prudent safety feature.

Stairs also need safe handrails to help prevent fall injuries. Handrails should be on both sides of open stairs to act as guard rails. The hand rails should be at least 30" high and have a usable hand grip on the top. Lastly, a common deficiency on exterior stairs is to use diagonal safety bars rather than proper vertical balusters. Children can fall through gaps as small as 4" and can climb non-vertical surfaces so the handrails need to have vertical balusters no further than 4" apart for the entire run of the stairs.


Guardrails are needed anywhere there is a drop greater than 24". Like handrails, it is common for guardrails to be incorrectly build where children can climb over or through rails. Guardrails need to be at least 36" in height, have vertical balusters no more than 4" apart, and be able to withstand a strong impact from full sized adults.

Guard rails can be installed either by bolting down into the floor from the top or by bolting into the floor from the side. The side mount system is generally preferred in new construction as water is less likely to get into side mount penetrations than into top mount penetrations.


Flooring on decks, balconies, and porches need to be able to withstand the elements, be safe to walk on, and help manage water run off. Common flooring materials are:

  • Wood Planks - Wood makes a great material for flooring but it does require maintenance to prevent rot. Wood can be slippery, particularly on northern exposures, and may require a gritted paint to improve traction for users. Wood planks should be installed with a gap between each plant to allow for expansion and contraction of the material.
  • Roll-On Water Proofing - There are a few different water resistant roll-on materials flooring can be finished with. These are typically installed over a plywood sub floor with water directed to the edge of the floor or to gutters or drains. Roll-on water proofing tends to perform well although is can be damaged by objects dragged on the floor.
  • Vinyl Sheet Material - Vinyl sheet material is an excellent water-proof product. It is installed in 12' sheet segments and needs to be chemically welded at each joint and at any other protrusions on the surface which are the typical weak points in the system. Vinyl deck surfaces are easily damages and water that gets under the system can cause hidden damage. Home Inspectors should review moisture levels under vinyl sheeting with a moisture meter.
  • Outdoor Carpet - Outdoor carpet was a fad from the 1970's but it still exists in some places today. This outdoor carpet should not be used on any outdoor surfaces as it traps water against the structure which leads to premature failure. This building material should be flagged as inappropriate by home inspectors


Roof systems are often added to decks, porches, and balconies to provide some outdoor shelter to users. In many cases, the main roof system of the house is simply extended to cover the additional floor space but in others, there is an additional roof structure in place.

Similar to the deck, balcony, or porch itself, these roof structures need a complete inspection of structure, building materials, and drainage. Common problems with these roof structures are inadequate attachment to the existing building (bolts are needed again), inappropriate or undersized building materials, and damage from movement or rot.

Final Safety Thoughts

Home inspectors need to be aware that decks, porches, and balconies are a leading place for deaths and injuries in homes. Every year there are many stories of under-built decks failing and collapsing under partiers trying to enjoy the outdoors. Children are killed when they climb over, under, and through guardrails and handrails and fall from heights, and many people are hurt when unnoticed rot makes stairs or floors unsafe for walking. Keeping home inspection clients, their families, and their friends safe requires attention to detail and willingness to point out even small concerns with these outdoor structures.

By James Bell - Owner/Operator of Solid State Inspections Inc.