42″42″ is the standard requirement for footing depth, Many times people like to go up to 48″ for good measure.
How deep should my footing be for my deck?
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.
What is the minimum depth below grade for the footings?
The minimum depth of footings below the surface of undisturbed soil, compacted fill material or controlled low strength material (CLSM) shall be 12 inches (305 mm). Where applicable, the requirements of CBC Section 1809.5 shall also be satisfied. The minimum width of footings shall be 12 inches (305 mm).
What is the standard footing depth?
Depth of Footings
Footings should extend to a minimum depth of 12 inches below previously undisturbed soil. Footings also must extend at least 12 inches below the frost line (the depth to which the ground freezes in winter) or must be frost-protected.
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. Fill the bottom of the hole with 6 inches of gravel and compact the gravel with a 2×4 or wood post.
How deep is the frost line in Connecticut?
The CT frost line is said to be 36″ but rarely gets that deep. 42″ is the standard requirement for footing depth, Many times people like to go up to 48″ for good measure.
What size footings do I need for a 6×6 post?
FOOTINGS: – Poured concrete footings should be a minimum of 8” wider than the posts (4×4 post – 12” min. width, 6×6 post – 14” min. width), a two level deck or deck with roof – 24”x24”. – The bottom of the footings must be a minimum of 36” below finish grade level.
How do you calculate footing depth?
Measure from where the concrete foundation starts above ground to where it meets the footer using a tape measure. This will give the measurement of the depth of the building’s foundation.
What is minimum footing size?
Minimum Thickness of Concrete Footing
| Type of Footing | Minimum Thickness |
|---|---|
| Masonry | 250 mm; twice the maximum projection from the face of the wall |
| Plain concrete | 200 mm, or twice the maximum offset in a stepped footing |
| Reinforced concrete (depth above bottom reinforcement) | 150mm 300mm |
How deep should footings be for a 6 foot wall?
All footings should be a minimum of 150mm (6″) in depth, with the bottom 350 – 400mm (14-16″) below ground level on most soils. For clay soil however, thicker and deeper footings should be used.
How deep should deck posts be buried?
Set footers a minimum of 6” below the frost line for your area to prevent movement during freezing temperatures. Pour about 6 inches of all-purpose gravel into postholes and pack the gravel tight by using the end of a wooden post.
What kind of concrete is used for deck footings?
Decks and other permanent structures require deck supports and footings made from structure strength concrete mix. QUIKRETE 5000 is recommended for footing applications because of its heavy duty, 5000 PSI strength. Add the QUIKRETE 5000 concrete mix to the form.
Should deck posts be set in concrete?
A deck post should always be placed on top of footing, not inside concrete because it can break. The photo on the left shows a post set in a bracket that has been mounted to the top of a footer. The photo on the right shows a post that has concrete poured around it, which can lead to a crack like you see here.
How deep should 4×4 deck posts be?
Dig post hole so diameter of the hole is 3 times the width of the post (i.e., the hole for a 4” wood post should be about 12 inches wide). The depth of the hole should be 1/3-1/2 the post height above ground (i.e., a 6-foot tall fence would require a hole depth of at least 2 feet).
Should you use 4×4 or 6×6 deck posts?
Deck posts must be a minimum of 4×4 according to the IRC but many jurisdictions require a 6×6 post as a standard. To avoid code violations, many deck builders choose the 6×6 even if the 4×4 is acceptable.
Is it OK to put pressure treated wood in concrete?
Pressure-treated wood is required whenever you attach framing lumber or furring strips directly to concrete or other exterior masonry walls below grade. Note that this requirement is only for exterior walls, as these may wick moisture onto the lumber.
How long will a 6×6 treated post last in concrete?
A PT post will last a long time in concrete, maybe 5 to 10 years in soil alone. I suggest you embed the post in concrete, trowel a peak around the post so water runs off, and don’t let the PT post come in contact with the ground.
How long will a treated 4×4 post last in the ground?
A treated 4×4 will last 20 to 25 years in the ground if the conditions in the soil and climate are favorable. That number could increase to 40 to 75 years if you install the treated 4×4 in a cement ring rather than the soil. There are a few factors that influence how long the 4×4 can last in the ground.
What should I put between wood and concrete?
Anyplace where wood meets the ground or concrete, the lumber must be pressure treated. For additional moisture protection, a gasket or strip of closed-cell foam can be installed between the concrete foundation and the sill plate.
Can you put pressure-treated wood directly on the ground?
Pressure-treated wood is softwood lumber, typically southern yellow pine, that’s been chemically treated to resist rot, decay and termites. Lumber treated to “Ground Contact” has a high chemical retention level and can be placed directly on or in the ground with better protection against rot or decay.
How do you keep wood from rotting in concrete?
Consider Adding Posts to Concrete
From here, you should fill the hole with about 6 inches of gravel. This will prevent rotting by ensuring that the post is kept dry when water makes its way into the soil. Place the post in the gravel, then fill it with a batch of cement until it reaches the top of the hole.
