Drainage, Well, Underground Electrical...Done!

After insulating the foundation we immediately started work on the underground service, well water line, and the drainage tile around the foundation.  Wade's Excavating dug a 3' deep trench from the utility pole.  Local regulations require 6" of sand at the bottom of the excavated trench.  The trench contains conduits for both electrical and data (cable, internet, phone, etc).  Photo 1-1, 1-2  shows Trevor Leonard (709 Electrical) fitting conduit for the data conduit.  Photo 2-1, 2-2 shows the length of the trench back to the pole.  Once the conduits are installed and expansion joints are added at the utility pole to account for the PVC expanding/contracting with temperature, the whole trench is backfilled with another 6" of sand.  Regulations require that there be 2x6 pressure create board placed over the trench (Photo 3).  This is really just a safety measure to ensure that if anybody is digging they will presumably dig into the plank before tearing up the electrical conduit.  Newfoundland Power came and did their final inspection yesterday and gave us the thumbs up to backfill.

Running the water line for the well pump was fairly easy.  We bundled the 1.5" water line with the electrical TEC cable and the copper ground wire.  It was simple wrapped with electrical tape ever 3' and then ran from the well location, along the footing of the house, over the electrical service, and into a 4" piece of abs that was specifically placed under the footing before the footing was poured (Photo 4-1 through 4-4).  Since the location of the well water line was located on the foundation drawings, we simply added some 45's and a couple lengths of 4" abs to bring the abs pipe up to slab level at the location of the slab penetration marked on the drawings.  The 4" ABS stub can be seen on Photo 4-5.  Once the vapour barrier is in place, it will be tape sealed to the ABS before pouring the slab.  The ABS pipe will be filled with spray foam to provide an air tight seal.

Running the drainage tile was fairly simple....just uncoil and wrap around the foundation while using fairly large rocks to hold it in place around the footing (Photo 5-1 to 5-3).  I purchased the weeping tile that has a highly permeable sock over the whole length that will help prevent larger pieces of sand from clogging the weep holes in the drainage pipe.  At a couple of corners of the house i decided to add a coupe of tee-wyes (Photo 5-2) to add clean outs that will come up to ground level should I ever need to inspect or clean the drainage system.  Drainage stone will be delivered today and will be used to cover the drainage tile.

Its been a busy week.  We accomplished a lot if you take the weather into account.  The site work is almost complete (Photo 6).  The Flatrock Passive House foundation will change dramatically next week....Backfilling will commence on Monday!!!

Photo 1-1

Photo 1-2

Photo 2-1

Photo 2-2

Photo 3

Photo 4-1

Photo 4-2

Photo 4-3

 Photo 4-4

Photo 4-5

Photo 5-1

Photo 5-2

 Photo 5-3

Photo 6


  1. Hi David,
    Can you comment on the type of rigid foam used.....seems to be a variety of what is called styrofoam, used for packaging and foam cups etc, but for underground application, so some difference I assume. What is moisture absorption characteristics.......
    40 years ago such foam was available in 4x8 sheets and did not stand well and also absorbed moisture.
    I have used SM rigid with success underground that was in place 30 years, but when I used the same to insulated a cover of a dug well, over about 8 years it got soggy with absorbed water.......It was 2 in thick , attached underneath plywood cover, but then a black waterproof material was on top of the plywood , exposed to the summer sun. I assumed the extreme heat differential caused it to absorb water, as it is not supposed to. Water content will reduce the insulating value I suspect.
    Good workmanship. Nfld power discourages underground service in my opinion, as they gave me a hard time 5 years ago. A few years ago it was required to be 24 in to the top of your conduit, now 30 in plus plank.......would not a red plastic tape serve the same purpose as the plank. I believe this underground conduit will fill with water after a few years, from condensation, but should not hurt the lines.

  2. Hi Winston,

    The architect specified type II EPS (NL styro make it locally). EPS has good moisture properties. Long term studies show that it maintains R-value out 30 years+ even when buried. Even if it is water logged it doesn't change the R-value significantly. The big issue with SM is that although it has good subterranean properties, its global warming potential is huge compared to EPS if they use a non-CO2 expanding agent to extrude the foam. For that reason people often use EPS as it fits with making choices for Passive House related to minimizing GWP.

    I didn't have any problems with NL power in this case. They came, did the inspection and it was done. Funny but I expect they didn't like having to come and do the inspections. I agree that the conduit will probably fill with water. I know when I built my house, I ran an underground cable to my shed through a conduit. I plugged the conduit ends with a kind of plumbers putty to prevent this from happening. Not sure if it worked or not but for the sake of a couple of dollars...no big deal.

    They require the planks now probably because they will provide quite a bit of resistance when digging through them when they are anchored in the ground. Once the tape is sheared there would be no guarantee that the operator would see it but I am pretty sure he would know that the plank was there.

    BTW, net metering has been approved for the province....only 5 MW but its something......

  3. Your water line seems to be small, maybe only .75 in dia? Or just appears that way?

    1. It must be just the way it looks. The TEC cable is about 3/4" -7/8", the water line is about 1.5-2",



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