3 May 2012
The next great modern project has finally broken ground (hurrah!) and it’s a good thing because despite how busy we have been, I needed something major to spend my time on.
I thought I would include a few images from the SketchUp model I made (probably a year ago) as an introduction to the project because these project are pretty boring in the beginning. This house sits on a 5 acre piece of property and is covered in trees – way more than I have shown here. I originally introduced this project as the last post I wrote in December last year (here) and I included wall sections, 3d images of all the elevations, and for fun – a breakdown of the drawing set and project features. Ever wonder how many doors are in this house or how many pages are in the construction drawings? Go read that initial post and find out – I think it’s pretty interesting what goes into these projects from a documentation standpoint.
This house should be really interesting to watch come together and as much as I really like to design, I also really like construction administration. There are times when I think I missed my true calling as a contractor. Well, that’s not really true – I just like being on the job site, seeing things get built, and hearing (and telling) tall tales. If you’ve never had the good fortune of spending time on a job site, you don’t know what sort of stories your missing.
This is a picture of the job site … pretty pastoral for being in the city. The project site is fairly unique in that this stretch of residential lots are all 5 acres in size and lead downhill to a creek (or as FEMA calls it, a “Flood Plain”). The horses belong to the neighbor but that doesn’t mean we can’t look at them. Another feature to this area is that unlike most residential communities (at least where I live) nobody puts up privacy fences so when you stand out on your back porch, not only to you get to look out on your impressive property, you get to see everyone else’s land. It really does make for a wide open, rural feeling.
As I mentioned before, the project started off in earnest just a few weeks ago and right off the bat we had a problem. Despite the fact that we had drilled test boring and had a geotechnical report prepared, that all happened last year when we were in the middle of a terrible drought. Now, when we drill our piers, we are hitting water … and that’s not good. The two guys in the picture above are overseeing the drilling process. The guy in orange is Bruce – he’s the project superintendent. The other guy is a 3rd party engineer required by the city to be on hand to observe the drilling.
Talk about a boring job. That poor guy has to stand around all day for the next 3-4 weeks watching 4 or 5 other guys drill piers. Every now and then he marks down the depth on a piece of paper but he literally does 15 seconds of work out of every 30 minutes.
This is what it means to drill a cased pier. If there was no water, you would drill down to bedrock (in our case – 15′ – 20′ deep), pull the drill bit out, put some steel rebar in the hole, fill the hole with concrete. Simple right? When things go right, a good crew can drill between 60 and 80 piers a day. When things go wrong and you hit water, things literally and figuratively get messy.
(ps – look at all those trees on our site! Want to know how many we cut down to build this house? None)
To drill a 12″ diameter cased pier this is how the process goes:
- Drill a 16″ hole down to the prescribed depth
- The hole starts to fill up with water or collapses( (imagine digging a hole in the sand the beach when your close to the water)
- Stick a 13″ diameter steel pipe down the hole to help keep the water in check and stop the hole from collapsing
- Swap out drill bits on the drilling rig – put on a 12″ drill bit and re-drill the hole within the steel pipe
- insert steel rebar
- pour concrete into the hole but as the concrete rises, pull the steel pipe out at the same rate. The concrete will keep the hole from collapsing
See why the process slows down A-LOT when you have to case the piers? Oh yeah … it costs a lot more so make sure you have some contingency money in your budget.
Ugh is right.
The length of the pipe is spray painted on the side of the steel pipe - in this case it’s 22′.
This guy gets to shovel dirt out-of-the-way as the initial 16″ hole is drilled. He doesn’t have to shovel it all, just the bits that would fall back down into the hole. It is as bad as it sounds. On a side note, every time I’ve seen someone who has a backbreaking job to do – one that would have me weeping in a matter of minutes – the guy is always super small and skinny. I don’t know how they do it without hulking out.
This is the site superintendent Bruce (in the orange) and Barry Buford from Buford Builders saying to one another “yep, put a hole right here”…
Probably not. I will say that when I took this picture, I had zoomed in from across the lot so they wouldn’t know I was taking it. I would have gotten away with it except the 3rd party engineer dude started laughing and told them that the “architect took their picture”. He might have said it more colorfully, even added a particularly emphatic verb in there but I’ll let you figure out which one for yourself.
For those of you who haven’t bailed on this post yet, you might have wondered how do the get the steel pipe in the hole if the hole collapses when the drill bit get removed? Well, the hole doesn’t implode and the dirt that is collapsing in from the walls isn’t compacted. As a result, they are able to put the pipe in and then bang it into place the final few feet. I just didn’t know this was how they did it. I swear to you there was a few times that this guy almost flipped over.
Too bad … it would have made a great picture.