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Home » How To Pour Concrete Footings Underneath an Current Concrete Patio

How To Pour Concrete Footings Underneath an Current Concrete Patio

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Concrete footings are an essential a part of a construction like a pergola or a deck, and so they present the stable basis and assist for the remainder of the construction. Get set up ideas and recommendation on pouring concrete footings for a pergola or deck underneath an present patio from the consultants right here.

Must pour a brand new concrete slab? Learn to DIY your individual concrete patio right here.

In case your patio simply wants an improve, listed here are 9 methods to replace your concrete slab (and sure, you may paint it!)

You don’t must tear up your present concrete for a sturdy basis to your subsequent patio venture. 

If you’re prepared so as to add a pergola or a deck to your concrete patio, you may preserve the concrete slab AND pour new footings! I’m displaying you ways — and you may see the attractive pergola I construct on high of those footings right here.

This submit accommodates affiliate hyperlinks. Study extra and skim our full disclosure coverage right here.

What’s a Concrete Footing?

A concrete footing is the underside a part of a basis. For outside tasks like a pergola or a deck, footings are used to anchor the posts securely to the bottom. Footings are crucial to make sure that the construction has a robust basis and might maintain as much as common use and inclement climate.

Deck and pergola footings are usually set deep into the bottom for added stability. There are alternatives to put in a pergola with out footings, however for a big venture like this, I at all times suggest the longevity and security of in-ground footings.

Sorts of Put up Footings

For a deck or pergola, there are various choices for laying the footings and putting in the posts. Right here’s a short overview of the three customary deck and pergola footing choices — and keep in mind to verify together with your native council or workplace to make sure that your footings will meet constructing code.

In-ground footings with buried submit

This can be a quite common footing set up, and could be finished with or with no concrete block on the backside. Lauren and Brett used a buried submit footing for the viral hearth pit pergola with swings.

For this footing set up, a deep gap is dug and the submit is positioned within the gap, leveled and plumbed, after which the outlet is crammed with concrete or soil.

For added safety (and to fulfill code in lots of areas), the sort of footing usually features a concrete block (both pre-made or recent poured) on the backside of the footing gap.

Buried footing like this requires lumber handled for floor contact (pressure-treated).

This additionally limits the peak of the pergola or deck posts (or will increase the price of a tall pergola, to purchase longer posts) since a part of the posts are buried within the floor.

Premade deck footing blocks

Premade deck footings blocks (pier blocks) is usually a good choice for a small deck that’s not connected to the home, like our outside pool deck. Deck blocks are NOT advisable to be used as pergola footings.

A poured footing will probably be stronger and last more than utilizing deck blocks, particularly in areas with extreme climate, so I usually suggest going that route. Some codes don’t permit utilizing pier blocks for sure tasks, so once more, remember to verify your native rules.

To make use of pre-poured deck blocks (piers), the soil is compacted and leveled to supply a basis for the block. Then the block is positioned and leveled and the submit is positioned within the block, the place it’s held in place by the form of the concrete block (and gravity/the burden of the deck).

Deck blocks don’t require lumber handled for soil contact, however they’re restricted within the sizes of lumber you should use and the power of the footing.

Poured concrete footings

For a professional-level set up and the very best sturdiness, go along with poured concrete pier footings!

In a poured concrete footing set up, a gap is dug to regulation dimension, which is able to relying on the scale of the submit, the soil content material, and the depth of the frost line within the space. Then, concrete is poured within the gap, both straight within the gap or by utilizing a concrete tube type, to type the footing pier.

A submit bracket could be both set within the moist concrete earlier than it cures, or connected to the concrete pier utilizing bolts after the footing has cured (like I did with this huge stunning pergola.)

Poured concrete footings are the very best methodology of including concrete footings to an present concrete pad.

When to get a allow for a deck or pergola

Native constructing codes range, so remember to verify together with your native council, metropolis workplace, or owners affiliation for particular rules. Generally, you’ll NOT want a allow when:

  • The deck is lower than 30″ above grade (above the bottom).
  • The deck or pergola just isn’t connected to the home.
  • The deck or pergola is beneath 200 sq. ft.
  • The deck or pergola is in a personal yard and never close to the property line.

Due to the scale of the pergola (simply over 200 sq. ft), I had the native constructing division approve the design and utilized for a constructing allow earlier than I bought a began.

What’s your native Frost Depth?

Frost line depth is the depth to which the bottom freezes throughout the winter. Footings ought to usually be no less than 12″ beneath the frost depth to forestall heaving (transferring up) throughout the coldest months.

Footing Dimensions

The size of your submit footings will range based mostly on the construction dimensions, native frost depth, and native soil situations.

For this venture, the footings are going to be 8″ large and greater than 30″ deep.  The scale would range relying on the sort of construction you’d be constructing.

You would wish to first seek the advice of with an engineer and have plans authorized earlier than putting in your footings to verify they’re sufficiently big to your venture.

BEFORE YOU DIG: Name 811 to have the utilities marked. Don’t dig till the place the traces are!

Web site Preparation

When you’re pouring in-ground submit footings, you need to make it possible for the bottom is steady and well-compacted previous to digging the footing holes.

For pouring concrete footings in an present concrete patio — that work is already finished for the patio basis, so that you simply must clear the patio.

Supplies and Instruments to Pour Concrete Footings for a Pergola or Deck

When you’ve determined the format of your pergola or deck posts (and consulted an engineer about correct placement, depth, and reinforcement), you’ll want these supplies and touls to pour the concrete footings beneath the present concrete slab.



Do you know? You may lease instruments like an auger, angle grinder, hammer drill, and cement mixer out of your native Dwelling Depot.

Step by Step: How To Pour Concrete Footings Underneath an Current Concrete Patio

Step 1: Lay Out The Footing Areas

Primarily based in your design, find the location of footings and mark the middle of every footing with an X.

I like to make use of white tape caught on the concrete as a result of it makes the marks simpler to see and is a greater writing floor. Then, use an axe and hammer to mark the middle of the of X.

Preserve the format sq. with the three – 4 – 5 Rule. Use your tape measure to measure out 3 ft from the nook a method (x-axis) and 4 ft from the nook the opposite approach (y-axis), and, if it’s sq., once you measure the 2 markings at a diagonal the space will probably be 5 ft. (Bear in mind the Pythagorean theorem? 🤓)

Step 2: Lower Holes within the Current Concrete

There are 2 choices for chopping holes in a concrete slab: an angle grinder and hammer drill, or a concrete gap press (bore press).

Angle Grinder and Hammer Drill

Reducing a gap in concrete utilizing an angle grinder and hammer drill takes a while, however prices lower than renting a concrete gap drill.

You’ll rating the sides of the sq. gap with the grinder, after which use the hammer drill to interrupt up the concrete into items to take away it.

This can be a good choice for chopping a 10-12 sq. inch large gap.

Concrete Gap Drill (Bore Press)

A concrete gap drill will lower a pleasant clear round gap within the concrete slab. I choose this once I can as a result of it saves time and offers a really clear lower edge.

Renting a concrete gap drill usually additionally means hiring the skilled who runs the drill. Native costs will range, and in my space of central Utah, I paid $100 per gap. Positively value it for the time and mess saved!

After the core was lower, I used a hammer drill to interrupt up the core to take away it from the outlet.

Observe that the concrete gap drill does require one further gap to anchor the massive drill, however that’s simply patched after.

BEFORE YOU DIG: Name 811 to have the utilities marked. Don’t dig till the place the traces are!

Step 3: Dig the Holes Beneath the Concrete Patio

Use a submit gap digger and/or auger to take away the dust to dig the holes.

I deliberate to lease an auger, however the soil beneath the patio was a great soil: loamy clay soil and simple to dig by hand. So I dug the holes manually with the submit gap digger. It took me about half-hour per gap to dig my 30-inch deep holes.

If the soil had been rocky, prefer it usually is in my space, I might have wanted to lease an auger.

If the soil had been sandy and fewer steady, I might have additionally wanted so as to add a concrete tube (sonotube) for added stability for the footing.

Step 4: Droop Rebar Earlier than the Pour

This pergola required footings with 28 inch #4 rebar within the middle, 3 inches above the underside of the outlet for added tensile power. (Bear in mind, seek the advice of an expert engineer and your native code to know what rebar is required to your footings.)

The simplest technique to place the rebar is to put a bit of scrap wooden throughout the outlet and droop the rebar utilizing baling wire. This holds it in place for the pour and is simple to take away.

BONUS: Add Watering System

This consumer knew they wished to have hanging planters on the pergola, so earlier than we poured the footings, the landscaper stopped by to run some pipe from the primary sprinkler system up by way of the footing gap. This made it simple for them to tie a drip system for hanging planters into their common watering automation.

Step 5: Move Inspection Earlier than Pouring

As soon as all of the items of rebar the place suspended, I used to be in a position to name and have the inspector come and approve the holes.

Relying in your venture dimension and native space codes, you might or could not want the holes inspected. Due to the scale of this pergola, I did.

I dug my holes barely greater than required to be on the secure facet, and, after clearing some particles from a beforehand buried railroad tie, handed inspection.

Once more, soil situations (akin to sand) could require a sonotube (concrete tube) to create a extra uniform concrete footing, if soil is much less steady or sandy.

Step 6: Shield the Concrete Pad

Earlier than you combine and pour the concrete within the gap, remember to defend the present concrete pad! This preserve your patio clear and can make the distinction between your completed footings trying like an inexperienced DIY job and looking out like a professional.

In a bit of plywood, lower a gap the identical dimension as your concrete gap, and place the plywood straight over the outlet. Then pour the concrete by way of the plywood gap into your footing.

Step 7: Combine and Pour Concrete

You may lease a concrete mixer or combine by hand like we did in a wheelbarrow.

I used an internet concrete calculator to determine what number of complete baggage we wanted. We ended up utilizing about 2.5 80# baggage of concrete per gap, and every gap took about half-hour to combine and pour.

Simply observe the directions on the bag so as to add the water to the proper consistency. Then pour and scoop the concrete into the outlet. The plywood will preserve the splashback from getting on the patio!

Because the concrete will get to the highest of the footing gap, take away the plywood and punctiliously clean out the highest of the footing.

Tip: Pouring concrete into dry soil could pull the moisture from the concrete and lead to a weakened treatment. If the soil in your footing gap may be very dry, take into account dampening it (however not sufficient to create standing water within the gap), or utilizing a concrete tube. Correctly moistened soil (or a ready concrete tube) will preserve cracks to a minimal and provides the strongest pour.

Step 8: Stage the Concrete

After the concrete has cured a bit, you need to stage and clean the highest of your poured footing, to match the concrete patio stage and end.

Use a small trowel to stage the highest of the footing with the concrete patio and convey the “cream” to the highest. Clean out the highest of the footing.

Concrete “cream” is high layer of concrete that’s major smoother cement with no gravel combination seen. Bringing it to the highest provides you a very nice trying end and helps the floor power.

Step 9: Connect Put up Bases

Now you’re prepared to connect submit bases to your deck, gazebo, or pergola to your DIY concrete pier footings. For this pergola, I used these Simpson Sturdy Tie Hid Put up Bases — see the remainder of the pergola construct particulars right here.


Pouring concrete footings beneath your present patio is an effective way to have the foundational stability it’s essential to add a pergola or deck and make your patio an incredible household hangout!

Concrete Footing FAQ  

How deep ought to concrete footings be?

Concrete footings want to increase beneath the frost line. See the map and hyperlinks above to find out the frost depth to your space.

Do I want rebar in footings?

Most footings require no less than some rebar reinforcement. Test your native constructing codes and seek the advice of with a structural engineer to your venture.

How do I calculate concrete footings?

Figuring out the quantity and placement of concrete footings for a pergola or deck will depend upon the scale and format of the deck and width of your posts.

Seek the advice of an engineer and your native constructing code workplace to make sure you have ample assist to your construction.

Is a footer vital on a concrete slab?

To construct on high of a concrete slab, you should use a bracket designed for that function to anchor your pergola, gazebo, or deck straight to the present concrete slab, if you happen to choose that over a footer. The slab will usually should be crack-free and no less than 4″ thick with a advisable 12″ complete depth on the skin edge.

A concrete footer like we confirmed above offers you far more power and sturdiness, since it’s dug a lot deeper into the bottom than the concrete slab is poured.

Pouring a concrete slab? For a patio, driveway or sidewalk, no footer is required. For a basis of a house, storage, or shed, YES you will want a footer for the muse. That’s not what this tutorial covers 🙂

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I’m the husband of the superb Cassity of Remodelaholic. I like to downside resolve and to design and construct issues inside and outdoors the home to make life higher. I’m an expert Panorama Architect by commerce and love the outside.

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