Ready to pour the floor

The last week since my last post we've worked really hard to get ready to pour our basement floor.  Not many pictures but some really interesting stuff and a lot of money out the door.

Last week our GeoStar Mechanical finished drilling the loop for our geothermal system and brought the main lines into the basement. Our flatwork contractor wanted that done before he finished compacting.  The drilling process is actually quite interesting.  The shape of the bit allows them to essentially drive it fairly accurately to a given end point.   They have a locator that operates something like a stud sensor so they can follow the tip.  When they were describing it to me my programmer's brain was picturing a little robot with a drill head on it but the mechanism is actually much simpler.  The tip is shaped something like a duck bill, flat and angled in one direction.  So when it moves forward it will go in the direction the point is facing.  To make it go straight they simply start it spinning.  The tip is connected to a steel pipe that can bend to a certain extent over long distances.  When the tip comes out of the ground, they simply attach some pressure cuffs to it(think Chinese finger puzzles) and pull the tip back, thus pulling the pipes for the ground loop back through the hole and up to the drilling rig.  With this mechanism they were able to drill all 6 loops in less than 8 hours through ground that we probably couldn't have gotten excavation equipment into anyway.

So why not just use traditional excavation and slinky coils?  There are a few reasons we decided against that.  First, the horizontal boring allows us to put the pipe down 10' or more.  The deeper the pipe the more consistent the temperature of the ground and thus the better they can calculate the loads required to heat a house.  If you do a geothermal loop wrong it's a pretty big mess and you won't get sufficient performance.  I think anyone would be pretty disappointed to spend $30k on a heating and cooling system that didn't heat and cool the house.  So depth was one reason.

Jamie from Geostar Mechanical drilling the ground loop.

Another reason is the ground composition.  We have what could be politely referred to as some pretty soft ground.  In the spring we won't be able to drive a lawn mower in there and a 4 wheel ATV may even have difficulty.  In a drier summer the surface is usually fairly dry but still soft.  This summer the ground just dried out the standing water before they started drilling.  Bottom line, if you take excavation equipment in there its likely you'll get stuck at least once.  Along with that is the fact that the trench would be full of water almost as soon as you start digging.  The fact that the excavator wouldn't be able to see the bottom means he wouldn't be able to get it smooth enough to prevent the kinds of uneven-ness that could cause the lines to break and create a huge mess.  Can you imagine total failure of your system because the pipes broke as they were being covered up?

But the wetness that causes the problems is the very reason I wanted to put the loop out there.  You get the best of both worlds between a closed pond loop and a ground loop.  The greater the conductivity of the ground, the greater the ability to both heat and cool.  I have heard great things about the kinds of efficiency you get out of geothermal, I am excited to see how mine performs given the choices we made so far.

The next thing we did this week was lay radiant floor.  Never done it before and I have to say that it was harder than I thought it would be.  It wasn't terribly physical in nature, and maybe I made it harder than it should be, but I put a lot of thought into how to lay out the pipes and a) I miscalculated the square ft and b) I blew the layout anyway. 

Side note... and this bit me both in materials both for insulation and radiant floor, when you buy materials make sure you calculate the sq ft on inside dimensions for the area you are actually going to do something with.  I had outside dimensions on my print and figured, "eh, how different could it be."  This is why I did very poorly in math.  Think about it, 8" walls on both sides is 16" multiplied by the length of the wall and you start getting some fairly significant dimensions if your walls are long.  By the time you over-order to make sure you have enough materials you end up with more than you can use.  It's alright, we can still use it, but now we're going to have radiant flooring in the kitchen and main bathrooms too.  I would be a lot more disappointed but I got a great deal on the materials going through Geostar so I'm not so horribly disappointed.

Our first try we failed our inspection but it's not really fair to say it's our fault.  My dad who's 80 years old and can still work way harder than I can... who worked tirelessly with me all day until about 10pm on Sunday and late into the night on Monday getting all the pipes connected to the manifold... who worked on it by himself while I had to go to work the last couple days was unable to get the system sealed up.  For those who don't know how this works, the system has to be able to hold air pressure in order to pass inspection.  Our system kept leaking air and he was unable to figure out where it was coming from.  He thought he had it sealed up but when the inspector came all the dials were at 0.  The problem is, he can barely hear and turns off his hearing aids because they whir in his ears whenever he bends over.  It just so happens that the pressure release valve in the test gauge was loose when it came from the factory(think the pin inside a tire stem) so it was leaking air.  Well, leaking is a bit of an understatement.  With his hearing aids off he couldn't hear the air gushing from the valve and thus it didn't hold any air for the inspector to see.  Fail.  So this morning I stopped down to the site before work and we got that all fixed up and, 24 hours(and $45 in penalties later), we passed our inspection and are now ready to pour. 

Special thanks to the crew from Hunt & Nieboer Concrete for prepping the surface and laying the slab insulation.  They should be out here pouring our floor by the end of this week or early next week.  Once the floor is down, it's time to backfill and then we finally get to the framing.

End of Month 1

I realized how long it's been since I updated the blog on progress.  The last couple weeks were kind of slow, a lot more work by me than other people.  The weekend after they pulled the forms I was able to get footing drains in but I realized that my plan for where I wanted my basement bathroom wasn't going to work.  So I went back to the drawing board on that, modified design and placement and finished the plumbing for that last weekend.  We also got some insulation on the frost walls, completed the radon system, and got our inspections on the rest of the foundation and the underground plumbing.  I have to say, I got a lot of satisfaction out of that green sticker for the plumbing knowing that I did all that myself with some helpful advice from my brother-in-law and the book Code Check from Taunton Press.

Just as an aside, I got the Code Check book in the mail on Saturday morning on my way out to work on the plumbing and within 10 minutes of going through the plumbing section I noticed a problem with my plan and made a small adjustment.  I would have failed my inspection without it.  Given what is in this one and how much it helped me I'll probably purchase the larger version to help me through the rest of the process.  So thanks to the folks at Taunton Press for producing such a helpful resource.

Anyway, that aside, there have been some less than positive results.  While it's not a huge deal, I learned some stuff about concrete.  Yes, I know, it cracks.  Luckily, even if it cracks, as long as they put a sufficient amount of rebar in it, it's not a huge deal.  The other thing I learned about is what I've heard called a "freeze-off" line.  That is what happens when they change out trucks and the stuff they have already put into the form hardens to the point where it doesn't mix quite right with the rest of it.  I have some pics of what ours look like. I've had a few people look at them and they say they are not too bad, but it can be a concerning sight to see in your brand new concrete wall.

Edit: I followed up with Terry McKinney who poured my walls and he said they actually used a different concrete mix between those lines so the color change is attributed to the difference in concrete mix.  Like any good contractor he is going to follow up by coming out to take a look but he was confident that was the problem. 

Tomorrow our geothermal contractor, Geostar Mechanical, will be drilling our loop, which should be an interesting thing to watch.  Jamie uses a horizontal boring rig to drill the loop which allows him to make sure they are in a nice straight line, no kinking or bending the pipe.  Plus, he can get the loop a little deeper than traditional excavation so the ground temperature is a little more predictable.

Thursday we should have our slab insulation delivered from Williams Insulation in Adrian, MI.  I'm hoping our pex gets here for the radiant floor by next Monday or sooner so we can get that down and the floor poured early next week.  Once that is done, we hand it over to our shell contractor.

Also done this week was to get a quote back from Great Lakes Insulation for Icynene spray foam insulation.  Icynene is quite an interesting product.  Check out the videos from their website because the expansion factor for this stuff is really incredible.  It goes on like paint and expands to the point that you have to cut it off in order to put the drywall on.  The R-value is around 3.6, which is not spectacular in and of itself.  However, it's strength is in its ability to seal the space with the high R value and not settle.

Here are some pics that round out the work done in August.