What are those giant tubes at Kelowna construction sites?

They look like giant steel tubes dug deep into the ground — a common sight in downtown Kelowna which is going through a construction boom.

The giant tubes are called friction pipe piles. But what exactly do they do and why so many?

For starters, the tubes are 36 inches in diameter and they’re driven way into the ground to a depth of 150 feet.

They’re called friction pipes for a reason. The friction between the pipe and the ground supports the entire building. That’s why they have to go 150 feet — to generate enough friction.

The method has been around for ages but isn’t used at every construction site but required when building in downtown Kelowna because the ground is too soft.

“They act as a footing,” Dan Martynov said. He’s in charge of the Mission Group’s 20-storey building called Ella, currently under construction at the corner of Ellis Street and Lawrence Avenue in downtown Kelowna.

“In typical construction you would dig out soil and you would put in strip footings or pad footings that are made out of concrete but because this soil is so loose and granular you can’t do that. You actually have to use the piles. That’s what holds the building up,” he said.

Ella will require 148 pilings. In comparison, the One Water Street highrise project in Kelowna’s north end will require more than 200 pilings. That’s because the building is going to be 36 storeys – making it the tallest structure in Kelowna. The last pile went in Tuesday.