porch and deck footings. anyone that has used one of these post hole diggers for digging holes for porch, deck or pier footings can tell you that its a miserable experience. not only is it usually impossible to dig the hole unless youre digging in beach sand but it gets very hard to get down to 4 ft below grade in a small hole because you cant
footings typically must extend below the frost line to prevent shifting during freeze-thaw cycles. step 2 dig footing holes about 6 inches deeper than required. step 3 fill the bottom of the hole with 6 inches of gravel and compact the gravel with a 2x4 or wood post. step 4
a strht concrete pier with a wider flat footing. a good size for a common backyard deck is a 10' or 12' diameter for the sonotube and a 20' base diameter. of course, you can get a 24' base size and it will spread weight over an even greater surface area. the one down side to this is the extra digging involved.
if you're building a simple deck, footings and posts should be placed less than 8 feet apart. however, if your deck will include a hot tub or roof, you must support that weight with additional footings. or, if your deck has many angles, additional footings are necessary.
as i mentioned in my blog post on frost heave and deck footings last week, frost heave can be a serious problem with decks here in thanks for visiting this is a blog about home inspections and home related topics in the minneapolis / saint paul areas.
up vote 2 down vote favorite. i am building a deck. how about setting 6x6 p.t. posts down on a concrete footing at 4 feet deep the frost line here and fill with gravel and soil, and then let the posts run high for the railings? this is instead of doing concrete piers and setting posts on them above ground.
how install concrete deck footings. pound a nail in at the point where your post must align, then run some string to the post install corner. use a square to determine 90 degrees. pound in a stake that corresponds perfectly to your 90-degree string, and tie the string taut onto the stake.
but even if footings are deep enough, ice lenses can latch onto the rough surfaces of wood and concrete and lift footings and posts from the side. that's why concrete piers poured in waxed cardboard tubes and smooth wooden installing deck posts work well for below-grade support. how to get a solid, frost-proof footing:
this puts the post-base connector at risk of corrosion and the post itself at greater risk of decay. pour the footing at least 4 in. higher than grade. uneven tops: its hard to plumb and secure a post base properly on top of a footing with a sloped top.
the deck code here says that the concrete footing must be 30 in below ground level and have a thickness of at least 8 inches i.e. to 22 inches below ground level . this which means the wood post is in the ground.
this video shows you how to build the base of a deck foundation or concrete deck footing, using quikrete quik-tube building forms. how to attach a beam to a post for a deck - duration: 2:06
deck footings. the size and depth of footings vary depending on your location and soil composition. for example, in northern virginia, a deck's footing needs to be at a depth of 24' below the ground. in more southern locations, many concrete footing details indicate that the footing can be placed much closer to the surface.
the hole for the footings should be below the frost line, as large as required by code typically 16 inches in diameter and 8 inches deep for 8-inch-wide piers , and flared. shovel or pour concrete into the hole until it reaches the top of the flared section. take care not to disturb dirt on the sides of the hole.
how to dig holes for post footings. correct deck construction starts with preparing the foundations. firm foundations will help to create a stable and long lasting deck of value. digging holes for post footings is the messiest and most unpleasant of tasks when you start a deck design, it is often the job that makes people look for short-cuts or even delay deck building altogether.
how deep to dig in posts. dig posts or footings to local code requirements or at least six inches below the frost line. always backfill under posts or footings with gravel for proper drainage. in warmer climates you can use premade footings. check with your local code enforcement agency for specifics. wood vs. steel and other footing options
digging your footings. your deck will not pass inspection with inadequate footings and the posts can be forced up by frost when the ground freezes, known as heaving which can destroy it. dig each footing 48 inches deep and 10 to 12 inches across, centered on the location you marked when laying out your deck.
a footing helps support the deck by spreading out the loads created by each post over a wider area. the wider base also helps prevent frost heave from lifting the deck. footings for porches are important in supporting and maintaining the integrity of the structure above.
you will likely need a structural engineers analysis to determine how deep the footings will need to be and the support beams structure as well. soil type for piers and footings. one cost factor for deck and porch footings is the equipment needed to excavate the holes and how much each hole will cost to drill/dig.
for example, the size of the deck plus whether it has a roof will change the depth of the footing. also, the soil type will alter the width of the deck footing. for example, say a deck footing is required to be 450mm diameter in stiff soil the footing will likely be increased to 600mm in diameter with soft soils.
deck piers and footings. in your case, the soil under each deck post may be called upon to support 3,000 or more pounds without flinching. the diameter of the hole will probably be no larger than 24 inches in diameter and may be as small as 12 inches. larger diameter holes spread the weight out over more soil area.
move the form out of the way and dig the footing hole down to the frost line or 4 feet deep. 5. repeat steps 2 through 4 to create the second footing hole. 6. set the footing forms into the holes. check that they're centered below the plumb bob, then backfill around the footing forms with dirt.