I’m a DIYer building a 22’x9′ porch (and having a great time doing it too).  When I applied for my permit I was told my 3 sonotubes of concrete down to frost level just wouldn’t do.  I was told I needed to get a footing poured at 6′.  I’m in Ottawa, Canada where I think the frost level is about 4-5′.

After sending 6 faxes to concrete contractors asking for quotes to pour the footing and posts for my porch and not getting a single reply other than one guy who said he was booked for the next 2 months, I started to despair (and actually considered doing it myself – that would have been a nice DIY disaster story, I’m sure).

I then came across a company called Techno Metal Post (www.technometalpost.com).  It is a foundation system composed of a galvanized steel post with one or two plates at the bottom.  The plates are actually more like just one turn of a helix so that when the post is rotated it drives itself into the ground like a corkscew.  This plate also serves as a bearing surface (and as resistance to uplift).  The diameter of the plate depends on the weight of the structure being built.

The post is actually composed of aboout 3′ sections which are welded together as the joint comes gets close to the ground (like a oil well drill).  Once the post is driven to below the frost level the top is trimmed and a bracket is welded on to support a beam (a tripled 2×8 in my case).  The posts are sheathed in a plastic tube.  I’m guessing that this is to isolate them from frost heave.

Any deviation from planned location due to rocks encountered in the ground is dealt with by welding on the last section at an angle so that the bracket ends up where it should be.  Presumably the angle can’t be too large lest the downward force of the structure create too much lateral pressure on the now not plumb post so I don’t know how they deal with big hidden rock.  I guess they back out the post and call in the back hoe in this case.

I was very impressed with the system.  Job very fast (they called me at work and by the time I got there about 2 hours later, they were finishing up the last of 3 posts).  The brackets ended up exactly where planned and I was building my porch beams that evening.  A nice touch was the heavy duty (rated to at least 9,000 lbs) screw adjustment to the bracket.  I was able to fine tune the height to exactly what I wanted to get my porch beam super level.

For jobs where the HO has an existing lawn or garden that they don’t want trashed, I gotta believe that this system would be very attractive.  The machinery to ‘drive’ the posts is pretty unobtrusive – the size of a small lawn tractor mower so even a lawn would be minimally damaged.

Cost me $400 per post (Canadian) which I think is comparable to trenching to 6′, pouring a 20′ footing and 3 posts and backfilling again (but I wouldn’t know since I couldn’t get any quotes).  And given the convenience, I would be happy paying a premium anyways.

Just thought you guys would like to know about this system.  And, no, I don’t work for them – I’m just a happy customer!

P.S. I just had a look at their web site for the first time.  Boy, they need a professional webmaster to fix that up!