There are two may factor that impact a deck footing cost, material and labour. The style of footing greatly impacting the amount of time required for installation. Material costs vary little between design but do impact the footing cost but less than labour. Different footing designs also limits code compliance varying by jurisdiction, of the five-footing, compared only two are code compliant in Calgary for decks over 24” high or attached to your house but are an option for ground-level decks. Check local footing requirements in your jurisdiction. Here are the quick numbers for footings cost.
|Type of Deck Footing||Cost of Deck Footing||Code Compliant in most Jurisdictions|
|8”x8” Deck blocks||$40-65||No|
|Pylex Screw Piles||$61-119||No|
|10”x48” diameter concrete column||$150-170||Depending on Soil bearing/frost level|
|Precast Stackable Cement Footings||$285-354||No|
|Engineered Torqued Screw Piles||$250-450||Yes, with engineer letter|
Number only tells part of the story of footing cost. Let’s go through each footing cost to see which will work best for your house and deck.
But before we do that, let’s discuss Code compliance. I am in no way saying a particular footing style or material will not support a deck. What I am saying is that every local government has a standard of which they deem acceptable for footings. These are often blanket regulations base on standard assumptions of the region.
For example, in Calgary, our frost level on average is 3’ (0.9m), so the city requires all footings to be below 4’ (1.2m) to ensure that a deck’s footings are below the frost level. Will a 3’ (0.9m) footing support a deck in some yards? Possibly but they need a standard for the entire city which varies in land as it does in people. There are steps you can take to minimize the impact of frost on a deck footing, but the rule is depth not drainage or any other possible solution.
The city of Calgary also has a blanket requirement for soil bearing. Of which I am very thankful for, for it allows one to plan deck footing throughout Calgary without being a geologist or hiring an engineer. But some yards in Calgary are firm enough to support a deck with a smaller footing then 10” (250mm) but this standard ensures that all decks in Calgary can be built efficiently without needless forms and studies.
So, for three of these footings, they can be used for ground-level, unattached decks, less than 24” (0.6m) high which doesn’t require permits and code compliance. But these standards exist to assist in building lasting decks. I think as much as possible, even without permits, should be complied with constructing a durable deck.
One last caution, a deck attached to a house, has a structural impact on the house structure, in particular the foundation. Ineffective footing will put undue stress on your house. Which can cause either the house or deck to be damaged or worse both! With a low deck, if you want to use non-complaint footings, not attaching it to the house will minimize risk.
Now enough of that. Let’s talk money and break down the cost of deck footings.
Deck Block footing Costs Break
Deck Blocks Footing Material Costs
It is hard to beat deck blocks on cost. For around $16-20, you can buy an 8”x 8” (200mmx200mm) concrete deck block and a bag of gravel for drainage. Load them onto your truck or even the trunk of your car, and you are ready to go.
If you have many deck blocks or you’re going to put landscape fabric and 2” (50mm) of gravel down underneath your deck. Order a one-yard bag of gravel that can be delivered for around $150 plus the deck blocks. Borrowing a few shovels of gravel for under each block will save you from paying for individual bags of gravel.
Deck Blocks Footing Labour Costs
As with all deck footing labour costs, how hard the ground is, will greatly impact labour. Deck blocks labour will be least affected by the ground. As you will barely be digging. Dig down a foot or so for you can put some gravel down and set the block below the beam. Digging a small hole, compacting gravel and placing the deck block should take less than 30 minutes each.
Deck Blocks Installations
It’s best to dig deck blocks down below the loam (topsoil) as it has very little load-bearing capacity. Deck blocks sitting on loam will quickly sink with the weight of the deck.
On top of that, loam has a high-water holding capacity. Loam can consist of up to 48% water. Practically speaking, a deck block sitting on loam is floating on water. Not only does it have a low bearing capacity, rocks sink in water and so do decks. But will be constantly rising and falling with every frost. Rarely returning to is original height.
Digging down a few inches and compacting gravel under the deck block, gives your deck a firmer foundation. Allowing water to drain away minimizing frost heaves in winter. The gravel also is easier to level providing a better footing base.
Screw/Helical Piles Footing Costs
Climbing a little in price than deck blocks additional stability and uplift. Not a new technology but rapidly increasing in popularity with ease of installation. The single biggest advantage, disturbance or lack of it. Screw piles can be installed without messy and dirty concrete. Without having piles of dirt to dispose of after digging in concrete columns. Clean and easy, that’s what screw piles are.
Screw Piles Material Costs
The length and strength of the screw make all the difference in price. At Rona, you can buy a 50” Foundation Screw – Steel from Pylex without an adjustable head for about $20. Or on Amazon, you can order a 5 pack 32” Pylex foundation Screw for around $340 including shipping. That’s roughly $67 each but the biggest advantage is the adjustable head. Torque the screw down to the correct depth and freely adjust the head to support the beam. Depending on soil strength, additional height may need to be added. A 24” (0.6m) extension will cost less than $20 each.
At Home Depot and Lowes, a Pylex Commercial 66 Foundation Screw supporting up to 5 000 lbs (2268 kg) per screw pile. Digging down over 4’ (1.2m), below the frost lines in many areas for a little over $80 but with no adjustable head.
Additionally, a ¾” (15mm) 4’ (1.2m) piece of rebar will assist with installation. Costing around $10 but will assist in screwing the screw straight and help to avoid movement and hitting roots and stones.
Screw Piles Labour Costs
Reduced labour is one of the biggest benefits of Screw Piles. They are easy to install. In good soil will take about 15 minutes but can be done in seven. The biggest challenge stones. Besides the pilot rebar spike, you are drilling blind. Who knows what is four feet down? The auger bit can bind on a stone or root slowing down installation. But way less time them digging a similar depth hole.
Screw Pile Installation
Best practise, is to hammer in a 4’ (1.2m) ¾” (15mm) rebar straight into the ground. Flush with the ground as a guide for the screw pile. This will both guide the screw-down straight but also alert you of any rocks or roots in the way. Turn the screw in place using a 2×4, start with a shorter one, increasing length as extra torque is needed. With 1’ (0.3m) remaining, give it a few good hits with the sledgehammer to compact the ground. Continue screwing till only 6” is left and then drive down again with the sledgehammer to ensure it’s in tight. If still easy to pound down, add 2’ (0.6m) extension and continue to twist in the ground increasing resistance.
For a full complete step by step guide, here is a link to Pylex.
Unfortunately, as DYI installation, these are not accepted in most areas as deck piles but in practicality, they are quick, strong and durable deck footings. With the advantages over deck blocks in their bearing below frost level. With the added benefits of uplift and lateral support. A really good footing option for decks not requiring permits. But the best thing is no dirt to dig and remove. That in itself is worth spinning around a pole for a few minutes like a tethered mule.
Poured Concrete Footings Costs
The traditional deck footing and by far the one I have installed the most. Basic in installation, solid, durable and bearing below the frost. Not rocket science but expect to spend some time in backbreaking work.
Poured Concrete Footing Labour Costs
Borrow a truck or have it delivered this one going to be heavy and cost a little. Six bags of concrete at $6 each, a 4’ (1.2m) sono tube to form the concrete for about $7 and galvanized saddle close to $10. For a total material cost of around $150 plus a truck to move 330 lbs (150kg) of premixed concrete per pile.
Poured Concrete Footing Labour Costs
Labour cost and time are very soil dependent, tools and most of all determination. If the soil is loose, it will not bear well but can be dug in 15 minutes, with about the same amount of time to mix the concrete. If the soil is hard, rocky or both, this is going to take awhile. You will burn through the 2 hours allotted time and your determination very quickly. Plan for two hours per concrete pile and hope to be pleasantly surprised. Digging all holes before mixing concrete will help with efficiency of time.
Poured Concrete Footing Installation
Grab a shovel, posthole digger, long pry bar and a bucket of determination. The first foot or so will be fun, but after that, you will need to grit your teeth and keep digging. A very little rock will be a challenge but that’s what you have the pry bar for. To pry them out of the hole. If the soil is hard and compact, that will be good for your deck but every inch will be hard to dig.
Yes, you can borrow a friend and rent an auger but all the problems with the hand digging exist with a power auger. The only difference is now you have company and a heavy machine to hold and control while drilling. Yes, not push but hold up. The auger is more likely to bind and stall going to fast with pressure then dry spin lacking pressure.
If you have a large enough gate or can take down a portion of your fence, you can also hire a skid steer to drill the holes. This is super slick, but it requires space for the skid steer and will increase labour costs considerably.
Drying fitting the tube a few times into the hole will help in determining what part of the hole needs to be shaved off to fit the sono tube. Once the sono tube is at the correct depth and height. Mix concrete in a wheelbarrow and pour it into the tube till full. Scrape off excess concrete with a block and install post saddles.
You can also install post saddles after the concrete is set, but that will require a hammer drill to attach the concrete bolts. Either way, the concrete needs a day or two to cure before starting the construction of the deck. This is one distinct difference from the other four footing options, curing time. Don’t worry. Your sore muscles will enjoy the time off.
Precast Stackable Cement Footings Costs
To be frank, I don’t understand the value of these, but it is a footing option. Requiring all or more work than poured concrete footings except without the mess of mixing concrete on site. Along with no wait time for concrete curing as the blocks come precast and ready to go.
Precast Stackable Cement Footing Material Costs
Consisting of a precast concrete base, stackable cylinders and an anchor rod. Height is determined by how many cylinders you add to the system. I have only been able to find American sources Ezee Tube for retail sales online. This may be due to Canada’s highly regulated construction industry, making it harder for a new product to gain approval from government bureaucrats. But in the United States Home Depot sells two sizes, for 3’ and 4’ frost line. The conversion is roughly $180 CDN or $140 US. But as I said its currently only available in the United States. So, I guess the conversion rate doesn’t really matter.
Precast Stackable Cement Footing Labour Costs
The same challenges as digging for a poured concrete deck footing. Dirt will need to be removed and a level surface created on the bottom. Two big differences to sono tube and mixing concrete. First, you will need to dig a larger hole both to fit the 22” (560mm) diameter base and large enough to work around as the cylinders will need to be carefully stacked, not to crack them by dropping. Concrete is strong, but dried concrete dropped from heights can crack with sudden impact and should be avoided.
Here is where my estimation of two hours to dig and install may fall short. The base is 100 lbs (45kg) and the cylinders 60 lbs (27 kg) each. An individual could carry alone, but assistance is highly recommended. Especially moving and setting the base. The cylinders would also be challenging as they will need to be lifted above the anchor rod and then lowered into place. No small feat with a 60 lbs (27kg) block. Doubling the hands involved will double the labour costs.
Precast Stable Footing Installation
Similar as already described but dig the appropriate size hole, large enough to work in. Compact gravel at the bottom before setting the base. Similar to screw piles a steel rod needs to be set in the middle except here it both guides and holds the precast blocks together. And the rod is set from the bottom of the hole not pounded in from the top. Then one at a time each the cylinders need to be lifted over the rod and lowered down to firmly resting on the precast. All while avoiding mixing concrete. Especially helpful on a site with limited water.
Ezee Tube has a pamphlet of each step and pictures of construction. Click the link here to read. As an added bonus, the final product can support 135 000 lbs (61 234kg). That is one heavy deck!
Engineered Screw Piles Deck Footings Costs
Saving the best for last. Engineered Deck screw piles are the best quality deck piles money can buy. In my humble opinion. The screw piles providing lateral and uplift support along with a solid soil bearing support. Anchored way below the frost level. In Calgary, with a frost level of 3’ (0.9m) most engineered screws piles professionally driven 7’ (2.13m) or more.
Involving engineering along with critical testing during installation. Are installed not to some theoretical strength but torqued till sufficient soil bearing is achieved. Many companies are offering a 10-year warranty on the pile strength. If that’s not enough to convince you. Many bridges and buildings around the city are underpinned using similar technology. And if a foundation fails on a building, often the solution is screw piles to underpin the sinking foundation.
Engineered Screw Piles Labour and Material Costs
Well, you will not be breaking a sweat here. Professionals all the way. From engineers to operator of specialized equipment, it will all need to be hired. The good news is often companies will include all these together. From site consultation, engineer specification and letter along with machinery and installer one phone call will do it all.
This is why I have not broken out the cost of labour and material. You cannot shop around for material or install it yourself. The company will use specific screws, engineered according to the engineered specifics. Installation must be done by an experienced installer familiar with the required torque and soil bearing capacity.
All without breaking a sweat or damaging your yard. The one drawback is machinery size. Some companies utilize smaller skids steer, but most companies to get sufficient torque use larger machinery. Providing incredible driving power to meet all engineer specifications but requiring 6’ (1.8m) access to the deck site. Making it unrealistic with many homes now only having 4’ (1.2m) side yards without any rear access. But if you have rear access and a large enough opening in your fence. Engineered screw piles are the best deck piles you can buy.