How deep should my Deck footings be?
The depth of your deck footings depends largely on where you live and your climate. Why? Well, it’s all down to the frost lines. Have you never heard of frost lines before?
What is the minimum depth of footings for frost protection?
1303.1600 FOOTING DEPTH FOR FROST PROTECTION. Subpart 1. Minimum footing depth. In the absence of a determination by an engineer competent in soil mechanics, the minimum allowable footing depth in feet due to freezing is five feet in Zone I and 3-1/2 feet in Zone II.
What is the minimum depth for footings in Zone 2?
Minimum footing depth. In the absence of a determination by an engineer competent in soil mechanics, the minimum allowable footing depth in feet due to freezing is five feet in Zone I and 3-1/2 feet in Zone II.
How many decking devices do I need in Minnesota?
These devices have an allowable stress design capacity of not less than 750 lbs each, so at least four of these devices would need to be installed on every deck. These aren’t specifically approved by the Minnesota State Building Code*, but if it’s good enough for the 2015 IRC, it ought to be good enough for us.
How deep should footings for a deck be?
For most deck applications, in most jurisdictions, the width of a footing should be 20 inches round and a minimum of 24 inches deep. It is important that the base of the footings be solid, and in many cases you will need to keep digging until you reach undisturbed soil.
Do deck footings need to be below the frost line?
Footings typically must extend below the frost line to prevent shifting during freeze-thaw cycles. Dig footing holes about 6 inches deeper than required.
Do you need a permit to build a deck in Minnesota?
Building permits are required: When a deck or a platform is more than 30 inches above adjacent grade. When a deck or platform is attached to a structure with frost footings. When a deck or platform is part of an accessible route.
How deep do holes have to be for deck posts?
At each location, dig a hole, deep enough to pass your frost line by at least two inches and wide enough to accept the cardboard form and leave an inch or two on all sides. On the safe side, dig your footings at least 48 inches deep, or check with your local code enforcement.
How deep is the frost line in Minnesota?
80 inchesAdditionally, water and sewer pipes need to be placed below the frost lines as well. Here are the 10 states with the deepest frost lines: Alaska (100 inches) Minnesota (80 inches)...Frost Lines by State 2022.StateFrost Lines (Inches)Minnesota80North Dakota75Maine74Wisconsin6546 more rows
Do deck footings need rebar?
Plain concrete deck foundations without rebar are acceptable under the minimum standards of construction established in the International Residential Code. However, placing reinforcing steel within footings is a relatively easy and inexpensive practice that can provide increased performance.
Can I use deck pier blocks instead of footings?
Pier blocks can be used instead of footings for a ground-level deck not requiring permits. Piers blocks can also be used if the frost level depth is less then the height of the pier block. Allowing you to set the pier block below the frost level on stable ground.
How high can a deck be without a railing in Minnesota?
A guardrail is required on all decks or any portion of a deck more than 30 inches above grade or above a lower deck. Deck guardrails must be a minimum of 36 inches high.
How big does a ledger board need to be?
Ledger shall be a minimum of 2x8 nominal. Where guards are required, outside joists and rim joists shall be a minimum of 2x8 nominal.
Why deck posts should not be set in concrete?
Deck Posts Will Rot When Set in Concrete The concrete around the post is acting as a bowl holding water. Just like a concrete swimming pool holds water, so does concrete around a deck post. The rain falls and collects on top of the concrete with no place to go except into the post.
What size footings do I need for a 6x6 post?
FOOTINGS: - Poured concrete footings should be a minimum of 8” wider than the posts (4x4 post – 12” min. width, 6x6 post – 14” min. width), a two level deck or deck with roof – 24”x24”.
How deep should a 6x6 post be in the ground for a deck?
The general rule of thumb when setting a post is that the depth of the post's hole needs to be one-third to one-half of the actual above-ground height of the post. So, a six-foot-high finished post ideally needs to be buried three feet into the ground.
What happens when you bury a footing in the ground?
Once your footings are buried below the frost line the ground will act as a barrier to insulate the soil below the footing from freezing in the winter.
Do you have to dig a foundation deeper than a flat surface?
If you are building into the side of a steep hill or beside a retaining wall you will have to maintain the minimum distance to grade not only vertically but also laterally. In order to achieve a suitable lateral barrier you may need to dig your foundation much deeper than on a flat surface.
How deep should a footing be in Zone 1?
In the absence of a determination by an engineer competent in soil mechanics, the minimum allowable footing depth in feet due to freezing is five feet in Zone I and 3-1/2 feet in Zone II.
How much sand must pass through a sieve?
Sand must contain less than 70 percent material that will pass through a U.S. Standard No. 40 sieve and less than five percent material that will pass through a No. 200 sieve (five percent fines), or be approved by an engineer competent in soil mechanics.
What Is a Deck Footing?
Deck footings are a vital part of a deck’s foundation; they allow support posts to better hold weight, prevent them from sinking into the ground, and keep the decking level.
Determining the Number of Deck Footings
Ultimately the number of deck footings your deck needs varies and is determined by several factors:
Turn to UglyDeck.com for All Your Decking Materials
Choosing deck footing and decking supplies you can trust is a huge part of taking on a decking project.
What type of fastener is used for pressure-preservative wood?
Fasteners for pressure-preservative wood shall be hot dipped zinc coated galvanized steel (HDG), stainless steel, silicon bronze or copper. Ask your materials supplier for an approved fastener (R317.3.1). Screws cannot be used to attach joist hangers unless specifically approved for such application.
How many handrails are required for a stairway?
Stairways having 4 or more risers shall have at least 1 handrail. The top of the handrail shall not be less than 34 inches or more than 38 inches above the nosing of the treads (to the top of the gripping surface). Handrails shall be continuous for the full length of the stairs and shall protrude from the adjoining surface by at least 1½ inches, but no more than 4½ inches, and the ends shall be returned or terminated into posts. Handrails with a circular cross section shall have an outside diameter of not less than 1¼ inches or more than 2 inches. Other handrails may be acceptable. See the specific code language to be sure your handrail does comply R311.7.8.
How far apart should joists be on a 5/4 deck?
Joists shall be spaced 16” on center for perpendicular and 12” on center for diagonal 5/4” deck boards Joists shall be spaced 24” on center for perpendicular and 16” on center for diagonal 2X” deck boards Plastic composite deck boards to follow manufacturers specifications.
How deep should a tread be for a stair?
Minimum tread depth is 10 inches. Treads with a depth less than 11 inches must have compliant nosing. Largest tread depth or riser height shall not exceed the smallest by more than 3 / 8 inch across the run of the stairs. Treads shall be level with a slope no greater than 2%.
How many inspections are required for a home inspection?
The approved plan must be on site for all inspections. Typically, 3 inspections are required:
How many inspections do I need for a deck?
You will need two or three inspections, depending specifically on how your deck is configured, and those inspections need to be scheduled ahead of time on a weekday, so keep that in mind as you plan your project. You’ll find more details about inspections below and in the packet.
How deep should a deck footing be?
The minimum depth to the bottom of the footings is 60 inches. The footing bottom diameter shall be based upon the attached table R507.3.1.
What happens when you break a footing in half?
When expansive soils grab on to the walls of a footing and pull it up, the bell at the bottom will hold the footing in place until the pressure exerted by the frost exceeds the tensile strength of the concrete. Once that happens, the footing will simply break in half.
How do deck footings heave?
How Deck Footings Heave. When a deck is attached to a building, the part of the deck that gets supported by the earth needs to have proper frost footings. The most common deck footing is basically a big chunk of concrete poured in to a hole in the earth. The goal is to have this chunk of concrete go deep enough in to the ground ...
How to prevent heaved footings?
Another step to prevent heaved footings is to ‘bell’ out the bottom of the footing, as shown in the photo above. The ‘bell’ shape at the bottom prevents soils from pushing the footing up and out, but it can also lead to a fractured footing.
How deep should a footing be in Minnesota?
The Minnesota State Building Code requires footings to be a minimum of 42” deep in the southern part of the state, and a minimum of 60” deep in the northern part of the state. The diagram below shows the dividing line. While footings need to be deep enough in the soil to prevent frost heave, the depth of the footing is only one part of the equation.
What are the problems with decks in Minnesota?
One of the most common problems with decks in Minnesota is frost heave. Today I’ll explain how this works, why it matters, and what steps can be taken to help prevent frost hea ve when building a deck.
How to stop soil from pulling up on concrete?
One step that can be taken to help prevent soils from grabbing on to the footing is to use waxed cardboard tubes for the footings, often referred to as sonotubes.
Can pier footings break in half?
Once that happens, the footing will simply break in half. When you consider the relatively low tensile strength of concrete and the tremendous amount of force exerted by frost, it’s easy to understand how pier footings can break. One step that can be taken to help prevent this is to use rebar inside the footings.
