Week 5 – Foundation Floor and Radiant Heat Installation

Day 35 – The weather is not cooperating but we are managing to make progress on the foundation.  Most people don’t ever realize how import the foundation is to the home—once you have a bad foundation and leaks in the basement, you realize all too quickly its role and importance in the overall home build.

This week we completed the pour for the foundation walls which we had originally planned for last week, but the weather held and we were able to do this work on Monday …. 6 cement truck deliveries and I thought it would never end—Ralph (remember the pumper guys) kept the big rig moving right along and the forms kept eating concrete.  We finally got to the end of the forms … phew; it was 3 hours of hard work for the foundation team.  They walked along the top of the wall like monkeys!

Here are some sample photos of the concrete pour and the results!

(Double Click Images to enlarge)

So now what – the basement floor is not poured yet and will be the last keystone in the foundation phase of the project.  Remember when I told you about the excavation dig and they had made an error and dug too deep?  Well this is where I meet my maker and we have to fill the basement floor back up with compacted material (the material we removed cannot be returned to the site unless certified by a soils engineer to a precise compactness—forget it, it’s cheaper to just buy dirt unfortunately L ). 

Nine truckloads of sand later the site was filled and tamped/compacted—this took a full day.  Matt the excavator guy was a key player on this task also.  He went to the Camano quarry and picked up the sand in his large dump truck (he also said he picked up a little more and he told me he could be fined an put in jail for driving an oversize load—so don’t say anything to anybody about him driving 5 miles back to my house with an overloaded truck—we could have had to make 13 trips for all I know).

Now that the sand was all in, we had to prep for the radiant flooring.  The diagram below shows how this will work; the layering goes like this:  compacted sand, vapor barrier, polystyrene insulation, wire mesh,  PEX pipe is attached to the mesh and finally the concrete will be poured to a level of 4”.

Dave Turner one of my longtime friends and former professional triathlete offered to come up to the hacienda this weekend and assist with the layout and installation of the PEX.  The layout was designed into 4 zones; each zone was connected to a manifold; the manifold will be connected to the boiler via a series of tubing /pumps back in the mechanical room.  Below is the rough in design as given by my supplier Janes Infloor Co.

CAD Diagram Basement Radiant Flooring

Even though I had studied this part extensively, it definitely underestimated the effort it took to install the PEX pipe on the wire mesh.  I thought it would take 3-4 hours (1 hour per zone) and in reality we started at 11am and completed at 7pm!

The layout starts with the ¾” tubes which come from the mechanical room (boiler) to the 4-port zone manifold.  We basically free formed the route from the boiler and laid the manifold pipe to the zone manifold; the route would take us to the future location under the basement stairs.  We also spent about 45 minutes before we started by outlining surveyers paint outlining each zone (bright orange paint in the pictures).  Bear in mind the CAD drawing and the "as built" plans could possibility be different and as we learned it was going to test us later in the “red zone”.

We started with zone A-2 (green) first and it was the furthest away from the manifold.  You're inclination is to just string a pipe from point A to B; however, in reality you need to follow the computer selected algorithmic path to ensure that you do not overlay pipe from another zone.  Try locating the manifold on the CAD drawing (hint:  it’s the red bar under the stairs) and then follow the green line from the manifold to zone A-2 using the arrows and then trace it all the way back to the manifold.  Each zone was layed out that way.

Installation of the pipe consists of uncoiling a 300 foot section pipe—each foot of pipe is marked by the manufacturer with the length relative to zero so you can understand how much you have used (or how much pipe you have left).  No zone can exceed the 300’ level—the payoff idea is that warm water from the boiler will cool as it loops through the pipe; if it’s longer than 300’ then you diminish the heat and therefore render the loop useless in the latter length of pipe.

As we were completing the installation of zone A-2 we realized that the CAD diagram and the actual install were not matching up—we were ending up with less loops than the engineered diagram.  This was the beginning of the customized install where we had to make up the zone area as we went along—it sounds complicated but really not.

The order we laid the pipe was zone A-2, A-4, A-1 and finally A-3 the red zone!  As it turned out the red zone actually extended all the way to the wall on the south; zone A-4 did not extend all the way to the wall on the east.  Since the red zone was only 140’, we averaged the zones and most zones ended up being around 250-275’ in length.

Once the zones were installed we had to pressure test the system before we laid the concrete--if there was a leak in the system we wanted to know now rather than wait until the concrete had cured.  This process involves hooking up the supply and return manifolds, using a "shark byte" fitting to connect the boiler supply/return pipes, and all of that was then connected to a compressor via a plain old brass valve (picture bike inner tube valve) and then filling the system to 50 PSI … this test for leaks will be successful if the system retains the 50 psi pressure and does not drop over a period of time.

Here are the photos:

2" Polystyrene Insulation

Wire Mesh over the Polystyrene

Two zones installed with 1/2" PEX pipe (Note:  look closely on the far wall, the 3/4" pipe will ultimately attach to the future boiler)

Four Zone Manifold

Final Test at 54 psi maintained for 24 hrs (notice the rain, it was a nasty early evening)

Zone A-2

The "Red Zone"

I’m happy to say we passed the first time and the system was still holding 54 PSI the next morning, that’s a big Yippy Skippy! J

Next week; we’ll try to see if the weather cooperates and we will pour the slab and have a few miscellaneous tasks before Dave (contractor) orders the wood from Cascade Lumber for the basement section of the house.  Wish us luck for good weather—we need two days without rain for the slab!!

Adios and have a great week.

(Special thanks to DT for a big help, job well done!)