Radiant Hydronic Slab: Home Construction Photos for our energy efficient home in Deep Creek Lake, MD

Construction Timeline: (Floor)
Follow the progress of our new home construction. (7/22/2002 - 9/17/2002)

NOTE: Newest pictures at the top.
Click on any image for an enlargement.

Sep 17, 2002 The final pour commences.

Despite getting up at the crack of dawn (for us) and driving for 3 1/2 hours to see the slab being poured, we arrived just as the pumper was leaving. This is how the slab looked just after being hand leveled.	We are using an acid etch and sealant on our floors to provide an "Art" finish with excellent durability and heat transfer, so the surface needs to be very smooth to begin with. These "Power Screeds" are used to provide a smooth surface.
While two guys work on keeping the edges smooth and flat, two other guys manhandle the power-screeds over the surface. We had glass fibers included in the concrete to resist cracking, so the screeding process also helps to keep them below the surface.	Click on this image to get a close look at the final surface quality. It's a far cry from the initial wet surface.
A quick photo-break before the "Welding Rod" crew head off into the distance. They had two projects going today, a foundation pour off Garrett Hwy, and our slab.	Here are the radiant heat pipes protruding from the concrete. It's already hard to remember all those loops below the floor. I noticed that the pressure gauge read zero when I arrived. I hope that's OK :(
A final panorama from the back corner of the rear wall. When we left the site at about 4:00pm, it was cool and overcast, but the slab was HOT to the touch. I see what they mean about concrete heating up as it cures.

Sep 11, 2002 The Radiant Heat pipes are laid.
So many clips, so little time :).

The Knisely crew arrived right on time at 8:00am to start installation of the PEX piping. Gary and Dan did all the hard work.	Eric supervises the setup. A spool of pipe is placed in the utility room where all the loops will terminate. Knisely has a program that takes the room sizes and heat loads and determines the pipe spacing.
The pipes are fixed in place with these COOL clips that screw into the foam board. Then the tubing is just snapped into the clips.	The guys snap chalk lines at the prescribed spacing in each zone, and then the clips are inserted.
Each zone is fed by a series of loops. Each loop is 250' long. This ensures that each loop gets a balanced flow of water. The start and end of each loop is fed back to the utility room.	The 4 zones are visible here. The garage (4) is the rectangle to the far left, the guest zone (3) is the pie slice in the center-left, and the Living zone (2) is in the center, and the Master Zone (1) is to the right

Sep 9, 2002 Laying the slab insulation.
The slab is insulated from the ground using 2" of extruded foam block.
This provides an insulation value of R10.

First we laid down a roll of 16' wide vapor barrier. Then we started in the back corner and started laying the 4'x8' sheets of foam. We staggered the blocks on each row.	Holes were cut in the foam for pipes and forms. Cutting was performed with a regular hand saw (wood), and a keyhole saw that used a hack-saw blade. Having a relatively flat gravel bed made laying the foam "sub-floor" pretty easy.
Lisa got into the act (after fixing some car troubles). Here she is doing her "I can be macho too" act.	The blocks of foam were all joined together using Duct Tape. Lisa joked that you could hear the hammers being used at the other home sites, but at ours, all you could hear was duct tape ripping.

Aug 22, 2002 The floor begins by marking out the locations for plumbing rough-ins.
These photos are courtesy of Gary and Connie again.

Here you can see that Gary has laid out some of the wall positions (red lines) to enable him to mark the rough-ins for plumbing drains etc (red circles). Gary has also marked the positions for the concrete pads (red boxes) that will provide the structural support for the upper level Gazebo. Also note that the large piles of dirt in front of the house have been moved, and used as backfill.

The plumbing contractor (Heilig's) has laid out the sewer line run in white chalk. It leads down to the main penetration in the 6" knee wall.
In addition to the feeders to the normal sewer line, we have 4 floor drains in the slab to deal with water run-off in the sunroom, laundry, utility room and wheel-in guest shower. We also need a conduit in the slab to bring power to the kitchen island.

This site is all about building a cool, energy efficient house, that makes maximum use of earth sheltered design, passive solar heating and cooling, geothermal exchange energy management, and right sizing of the house for it's designated use. The home's placement is on a south-facing hillside in Deep Creek Lake, Maryland. This site describes the design process, the technologies used and the expected results. We also have a comprehensive Links Page for anyone who is also interested in designing a similar project.