Helical Piles: A Mimimal Green Foundation
by Lloyd Alter, Toronto on 11.30.06
We spent the morning wandering about the huge Construct Canada exhibition hall, Following the green balloons marked "Green Products" and getting depressed by the proportion of obvious greenwashers but cheered by the few gems. One that had no balloon but should have is the Techno Metal Post, developed in Quebec as TechnoPieux. In northern US and Canada foundations have to go below the frost line, requiring basements or crawl spaces. If a building is on piers, a big hole is dug and a sonotube is put in and filled with concrete. Invariably there is landscape damage, piles of dirt and a big mess to be cleaned up. It is very permanent and requires concrete and redi-mix trucks. Then there is the techno-post.
low impact installation of a boardwalk in a wetland
It has a helical base of different dimensions, depending on bearing capacity needed; they bring in a little robotic machine (the R2Dpost) and just screw it into the ground. The surface is barely touched, a plastic jacket protects it from frost, and you have an instant foundation. When it is time to turn the land back to nature, you just do it in reverse and unscrew the foundation from the ground. Also effective for holdbacks and tiedowns where usually concrete is poured. What a great way to reduce our impact on the earth, get a solid foundation and idle one more concrete truck.
Googling helical pile, we found a few other manufacturers, but this is available in Canada, northeastern US and France. ::Techno Metal Post and more complete french website at ::TechnoPieux.
I'm not sure if this would work on all soil types, like gravel.
Also, I'm not convinced that it would be more efficient for most jobs. I think concrete still makes more sense if you're close to the ready-mix plant. This system might make more sense out in the boonies.
So, I hope more treehuggers who are considering different foundation options for their prefab second home out of the city take a good look at this product.
Interesting product Lloyd. Thanks for bringing it to our attention.
I don't think it'd work in a area with lots of rock or gravel very well though. Maybe a rubble trench (or hole??) with this product in the hole itself would be a good compromise for rocky areas.
Well I hope most tree huggers wouldn't use the energy and resources to build a 2nd home.
This looks like a good product and I can see many applications for it. That being said I wouldn't dismiss the value of a basement in a house as it gives more living, storage and workshop space. With out a basement the house would need a larger footprint or more materals would be needed to add an extra level.
If the ground has lots of rock and gravel, generally it is not suited for deep foundations and what pile is best suited for rock and gravel? Concrete is a mess no matter what the pile job.
The concept that the materials to build would be better suited the closer to the manufacter has merit, but it seems that the availability would be just as easy either way.
One has to consider this: To put in concrete, then a hole needs to be driven with a truck mounted auger and what do we do with the drill cuttings from the hole? They need to be incorporated in the site area or shipped out-so more fossil fuel (more equipment on site) is burned and what drives the dirt to where do you dump these dirt tailings?
So the idea of implementing one equipment group for helical pile to do the whole job sounds pretty economic and eco friendly to me.
I have seen these helical pile bore through gravel, boulders 1 to 2 feet in diameter! But be suspect of the pile, many helical pile boast big capacities, but fail to deliver on the energy it takes to install. When the nessicary energy is applied to get in these gravel layers it desroys most helical pile materials.
HEATanchors.com makes a pile that delivers an eco safe high capacity helical pile. Take a look at their website.
I am the franchisee in the GTA area. I would like to clarify that yes we can install in gravel rocky conditions. We have different techniques to get our piles to the necessary depth.
We have installed over 300 000 piles, We are the first helical pile to receive a CCMC#. Which means that our piles have been tested and are approved.
We have done work for ducks unlimited in Quebec as well.
Even if you want to use concrete and you hit rock you would need to excavate. Also when you use concrete its a big concrete truck that arrives.
I have installed in many different types of soil conditions including the Beaches area in Toronto where I needed to go 25' deep.
Someone also mentioned that we would be better suited in the boonies for install. I would like to say that our machine is only 29inches wide. It is very well suited for urban areas, it uses vegetable oil instead of conventional hydraulic fluid which is very toxic in bodies of water.
Feel free to contact me if you have any questions.
Thanks,
Roger
905-467-3172
info@tmpgta.com