Do You Leave Sonotube in the Ground? An In-Depth Guide for My Friend
Hey there! Lillie here, your home improvement buddy. You‘ve probably seen those big cardboard concrete tubes called Sonotube on construction sites before. They‘re used to make concrete columns, footings, and poles. But you may be wondering – once the concrete hardens, is it better to leave the Sonotube in the ground or take it out?
Well friend, that‘s a great question! Whether or not to remove Sonotube after pouring concrete depends on a few factors. Let‘s take an in-depth look at everything you need to know about working with these handy concrete forms. We‘ll cover:
What is Sonotube and How‘s it Used?
- Definition and purposes
- Typical applications on the jobsite
- How Sonotube shapes and supports wet concrete
Should You Leave Sonotube in the Ground?
- Potential pros and cons of leaving in place
- When it may or may not be recommended
- Differences for structural and non-structural uses
Full Process: Installing and Removing Tubes
- Step-by-step instructions from start to finish
- Pro tips for doing it right the first time
Great for Fence Posts Too!
- Sizing, spacing, and depth tips
- Making installation a breeze
Pouring Concrete Around Sonotube
- Integrating forms into foundations and slabs
- Techniques for keeping them plumb and stable
The Benefits of Using Sonotube
- Cost savings, ease of use, strength
- Why contractors love them!
Plus plenty more Sonotube wisdom to help you become a pro! Let‘s get to it…
What is Sonotube and How‘s it Used?
Sonotube is a heavy duty cardboard concrete forming tube that‘s used to create columns, pylons, piers, footings, and posts. It‘s made using thick spiral wound and laminated paper reinforced with a water-resistant exterior coating.
Here are some of the most popular uses for Sonotube on construction sites:
- Concrete footings and foundations – Pour a footing, place the Sonotube on top and fill with concrete to create piers or foundation elements.
- Columns and supports – Form structural columns for homes, decks, porches, and garages with Sonotube.
- Sign posts and light poles – Quickly set poles and posts by burying and backfilling Sonotube.
- Fence posts – Much easier than digging and pouring each posthole independently!
Sonotube provides a round concrete form that can be removed after the concrete fully cures. It‘s a cost-effective alternative to built-in-place formwork. These tubes have been a construction site staple for over 60 years!
So in a nutshell, it allows concrete to be poured and shaped without needing full wooden forms. Just bend, place, and fill with concrete. Once cured, remove the Sonotube and you‘ve got a formed column, pile, or footing!
Should You Leave Sonotube in the Ground?
Now that you know what Sonotube is, let‘s tackle the big question…
Should you leave the concrete form tubes in the ground after pouring? Or should they always be removed once the concrete has hardened?
Potential Pros of Leaving In Place:
- Saves time and labor removing forms
- May provide added stability and protection
- Less disturbance to surrounding soils
Potential Cons of Leaving In Place:
- Cardboard may deteriorate underground over time
- Can eventually provide access for pests/insects
- May be required by code to remove after concrete cures
- Could obstruct future excavations
The consensus among builders is that for most structural uses, Sonotube should be removed after the concrete fully cures.
That‘s because the cardboard material, even with its water-resistant coating, will eventually break down over time when buried. This could compromise the strength of the concrete if voids form.
However, there are some exceptions where you may want to leave Sonotube in place:
- On fence posts or sign posts, leaving a few inches exposed above ground can provide stability.
- For light poles and other freestanding structures, leaving in place maintains a uniform appearance.
So check your local building codes, but in general its best practice to remove Sonotube once concrete reaching full strength. No need to risk long term issues down the road!
Full Process: Installing and Removing Tubes
Let‘s go through the full process step-by-step so you know exactly how to work with Sonotube on your next project!
Installation Best Practices
- Excavate – Dig the footing or post holes to required depth and diameter.
- Add gravel base – Place 6-12 inches of gravel or crushed stone in the bottom for drainage.
- Insert tubes – Lower the Sonotube into the hole. It should rest on the gravel base.
- Backfill around tube – Shovel soil around the outside and compact well. Leave 12 inches clear at top.
- Brace – Use wood braces across the top to hold tubes plumb while pouring concrete.
- Pour concrete – Fill Sonotube with premixed concrete, vibrating occasionally to settle. Fill to just below rim.
- Finish and cure – Once concrete is poured, allow it to fully cure based on spec – usually a minimum of 28 days.
Removal Process
- Inspect – Visually inspect concrete top surface for any damage before removing forms.
- Excavate around tube – Clear backfilled soil around the Sonotube, exposing approx. 12 inches.
- Slice – Use a utility knife to cut down the side of the Sonotube from top to bottom.
- Remove – Slowly peel away cardboard tube from the cured concrete. Take care not to chip edges.
- Backfill hole – Once Sonotube is removed, backfill the hole with soil, compacting as you go.
And there you have it – a complete step-by-step guide to installing and removing Sonotubes like a pro!
Great for Fence Posts Too!
In addition to concrete columns and footings, Sonotube is also an easy and affordable way to make fence posts:
- For most wood privacy fences, use 6 to 8 inch diameter Sonotube. For heavy duty fences, go up to 10 or 12 inch.
- Bury the Sonotubes a minimum of 24-36 inches below grade based on fence height and soil type.
- Leave at least 6 inches exposed above ground to allow attaching fence rails.
- Backfill half way up the exposed portion to provide lateral stability.
- Space the Sonotube fence posts 6 to 8 feet apart depending on fencing type.
So don‘t bust your back digging post holes – let Sonotube do the hard work and make fence installation a breeze!
Pouring Concrete Around Sonotube
When working on foundations or slabs, you‘ll often need to integrate Sonotube forms within the larger concrete pour. Here are some tips:
- Brace forms very securely so they stay perfectly plumb when pouring around them.
- Apply form release oil to the outside of tubes so concrete won‘t stick to them.
- Pour footings first, then place Sonotubes according to layout plans before the slab pour.
- Leave at least 6 inches of clearance around the full perimeter of the tubes.
- When pouring the slab concrete, vibrate and consolidate well to avoid voids.
- After curing, remove Sonotube forms and backfill any gaps with fresh concrete.
With good bracing and preparation, you can easily incorporate Sonotube forms into foundation and slab pours.
The Many Benefits of Using Sonotube
After seeing all that Sonotube has to offer, it‘s clear why contractors love using these concrete forms:
Lower Cost
- Sonotube is around 1/3 the cost of wood forming in many cases
- Faster installation reduces labor time
Ease of Use
- Lightweight yet durable cardboard construction
- Easy to transport and install on site
Consistency
- Provides uniform, professional looking concrete elements
- Less chance of defects compared to job-built forms
Material Savings
- Requires less concrete than solid forms
- Exact diameter means no overpour waste
High Strength
- Heavy duty tubes rated for up to 4,000 PSF load capacity
- Can support structural columns and deep footings
Adaptability
- Forms footings, posts, pylons, columns, and more
- Available in sizes from 3 inch to 5 feet diameter!
So if you‘re looking to save time, money, and effort on your next concrete project, be sure to get your hands on some Sonotube! Give me a call if you need help finding the right size and quantity.
I hope this gives you a great overview of how to use Sonotube concrete forms. Let me know if you need any more tips – I‘m happy to help!
Your friend,
Lillie