If you are planning to build a hot tub room, large deck, sun room or an addition that will not have a foundation to support it, then you should think about using the footing tube instead of the typically used sauna tube.
What’s the difference you ask? One concrete pier is the same as the other, right? Wrong.
A sauna tube is cylinder that is made from a paper product that is the same diameter throughout the entire length of the form. To install them you dig or auger a hole larger than the diameter of the tube that you are going to install. You then place the sauna tube in the hole and slowly and carefully backfill around it. You have to be careful not to back fill with any large rocks or thick chunks of clay, the reason for this is that sauna tubes are made from a paper product and it makes them prone to collapsing. If it collapses then you have to start again by digging it out. You also have to fill it full of concrete before it gets to wet or the ground around it becomes heavy from water. If they get wet they collapse in on themselves without any concrete to hold them. If the sauna tube collapses and has to be dugout it cannot be used again, you have to prepare another piece.
Footing tubes have a large belle on the bottom of them. You cannot use an auger to install them; you must use a machine (mini excavator) to dig a hole large enough so that the belle that is on the bottom will sit level at the bottom of the hole. Once the footing tube is installed you backfill around it. You don’t have to worry about what you are backfilling with; rocks and large clumps of clay will not collapse the sides of it. Big foots are made from a hardened plastic, this helps them maintain there bell shape. You don’t have to worry about pouring concrete in them right away, water and wet ground will not collapse them. They are stiff enough that once they are in place you can adjust them with the mini excavator by pushing on them to straighten them before pouring the concrete inside.
The bell shape acts as not only a pier but also as a footing as well. In many municipalities when they require you to have a footing at the bottom of your pier a footing tube qualifies as both. If you where to use a sauna tube then you would have to first frame a footing on the bottom of the hole, pour it, let it cure and then install your sauna tube the next day.
A footing tube is a one step process of installation; a sauna tube can be as many as 3 steps depending on the needs of your pier. You also get the luxury of being able to pour your concrete whenever you want instead of immediately. The footing tube has a sealed plastic top on it that stops water and snow from filling up the inside; you have to cut the top off to pour the concrete inside.
Footing tubes do have their limitations, they are made in certain lengths and as long as you don’t need anything longer then what they make you will be fine, if you require a pier that is 10 feet long then you will need to use a sauna tube. Depending on the installation sometimes a footing tube is just too short. Most times you only have to be below the frost line which is 4 feet in most areas. Footing tubes do come up to 7 feet in length, there are depth marks on the sides of the tube so that to find out how deep they are in the ground you don’t have to cut the top off and measure down.
Next time you are thinking about a project that requires piers take your time and give a footing tube a look, you won’t be disappointed.
Village Builders Inc.