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C

Cyanide

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1/4. This will be a long story. Just warning you.

I have a lakehouse on Sylvan Lake, Alberta. It is at the top of a large slope. Thinking about it as I write this, I would put this at 30 degrees, I think that's roughly a 50% slope. It has infloor heating (propylene, water 50:50, attached to a boiler, all the mechanical room equipment is new as of 2016, the tubes in the concrete floor slab are original). Alberta goes from 30C in the summer to -40C in the winter. Its usually pretty dry, but is getting wetter these last couple of years, but not by much.

In September the boiler starts making sporadic, loud 1-second-long groan sounds. Then everything is normal. Because of its nature it takes a long time to get a chance to observe this directly. But as the weather cools towards winter, this becomes more frequent. Soon, I am able to observe this and realize its the pump in the reservoir container (propylene/water). So, the boiler goes down to 10 PSI (from 19 PSI is its usual), then the reservoir pump starts to increase volume in the boiler-infloor heating loop and shuts off. So, I am thinking there is a leak in the in floor heating. I get boiler people in to see this twice and both times, despite hours of observation (coincidently both on days when we had unforecasted warming outside), they can't find any leak when pressure testing. Frustrated, I start a week-long pressure test , turning each zone off for 18-24 hours then re-opening it. I am able to find the leak. This leak seems to correspond to the wall that is facing the slope down to the lake (based on temperature tests on the floor, its the section that cools down when the loop is off). With the questionable loop turned off the boiler maintains pressure and no more reservoir drop. Keep in mind, during this time (longer than a month in total), I have gone through 125-150 L (30-35 gallons) of liquid (50:50 pro/water), which itself has gone somewhere.
 
2/4.

So, having isolated the leak, I walk around the foundation to see if I can get some hints. I find a large moisture stain right at the middle of the east foundation wall (facing the lake, facing down the slope). This stain starts to evapourate over the next couple of days, now that the in-floor loop is turned off. However, it is at this time that I also notice that there is a gap between the footer of the lumber wall sitting on the foundation, and the actual top of the foundation. This gap is about 1 inch at its widest, and tapers to nothing over the length of 6 feet. You can see the lighting in the house through this crack outside. The moisture stain extends right up to this gap, the top of the concrete foundation.

Looking inside I see cracks over the windows above this gap. But the many windows are level, open easily. In fact, during the winter all the doors in this house open/close much better than in the summer. Coming back to the windows for a second; the only window that is slightly off, is the window above the floor gap, and that window seems to be slightly higher to the corner where the floor gap is wider. Further, when these cracks are observed, it would seem that the section of wall that is above the gap, this section seems to be higher than the adjacent wall sections (these cracks seem to have that section of wall rise 1/16 inch [1-2mm]) based on matching irregularities in the crack's two edges.

So, to summarize so far: 1) we have a ruptured in-floor heating loop (inside a concrete floor slab that is not the foundation wall), 2) we have a wall that has gapped away from the foundation, over a 6 foot span, but this wall seems to have risen instead of sinking and 3) we have cracks in the walls near this gap, with the walls above the gap seeming to have shifted upwards.

Taking a step back we look at the construction of this place. The original home-owner and the neighbour had a feud over the boathouse that was built first on this property. Its a monster of a structure that looks like a grain silo. Great for storage, right on the water, but is an eyesore to the neighbour. Next structure on the property is the house. The homeowner was a single male and didn't need alot of "homey" comforts. So the main house is going to be a long box (short side of this rectangle facing the lake), with too much garage/shop and not enough living space. The neighbour sees his opportunity, tries to stop the construction as this "too much garage/not enough house" issue is against zoning laws. The solution: the homeowner adds a living room, turning this rectangle into an "L" shaped house. Legal battle avoided. But, this ends up being two separate, juxtaposed foundation pours. These meet up inside the house as a step down into the living room, this is all open concept floorplan (on one level, there is no basement, the foundation's only job is to hold up the house, the living room floor is concrete slab with flooring on top). The meeting of these two foundations corresponds exactly with the 1 inch end of that wall gap. This is also probably exactly where the infloor heating loop ruptured.
 
3/4.

I told you this would get long. We continue. In a panic I get a foundation guy in to see the house. He does some rough measurements (I end up doing them better later in the story). He declares the foundation is sinking, which was the fear I was already having. The distal corner (the tip of the bottom of the "L", away from the wall-gap corner/step-down from dining room to living room) is 3 inches lower than everything else. But, we look at the area under the deck where the two foundations meet and they definitely are moved in relation to each other (the second slab is shifted towards the lake 1 inch, and maybe down 1-2 inches, once again by matching up irregularities on the walls). We then measure the floor slab in the living room and find that the section of floor corresponding to the lakefront (the bottom of the "L") is level. But this section is lower by an inch than the living room floor that is away from the lake slope (thus the floor is uniformly sloped 1 inch towards lake). When we look outside there is a eavestroph downspout that travels through the deck before traversing away from the house. This seems to have broken open and is draining water to close proximity to the seam between these two foundations. But, there is ground cloth on the ground here, and this is not disrupted, nor is the profile of the soil. There is no signs of erotion at all.


At that time we conclude that the second foundation settled, rather quickly after construction. Then the walls went up and the windows went in. And all was good. But then later some water got somewhere and settled the ground, leading to this second shift in foundation. So the repair job will now include a foundation repair. So this jumps from a few thousand dollars, to hundreds of thousands of dollars. And, the insurance people are defensively declaring they believe they will not cover this.


Here we get to the final chapter. I start thinking about this foundation-expert's measuring techniques and they are not up to the standard that I would do (I used to work in a lab where everything was about standard approaches, disciplined measurements, replication, precision etc). So I get a laser level, make a sight-pole (a pole that stands upright without support, with a measuring stick glued to it and a level to ensure it is always level), put painter's tape along a section of every vertical windowframe and wall corner, standardize and calibrate my laser level so I can place it exactly on the same spot of floor in the dining room (outside the living room, on the first section of foundation). I also make a heavy duty aluminum hanger that can slip under siding, and fit firmly on the foundation top at any section of foundation outside that I want to measure, along with a measuring stick with level taped to it.
 
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4/4

Now, the measurements I get is that the floor slab is lower along lake slope facing wall, but instead of level along the lakefront wall, it is slightly dipped towards where that gap in the wall is, where the infloor heating is likely ruptured. Further, and this is the kicker....that whole lake facing wall of the foundation is not out 3 inches, its out only 2 mm (1/6 inch) and this has the area where the wall is gapped, the moisture stain was, the infloor heating ruptured, as the actual HIGH POINT of the foundation (along that wall). Now, my repeat measurements were done at -21C outside temperature, while the original measurements were at +5C.

So, it would seem that there was some shifting in the foundation (evidence: the matching irregularities when looking under the deck), this may have been before final construction (the windows are essentially level). Then over time the floor slab settled, to the point where it ruptured the in floor heating. Either that, or maybe a stray nail slowly corroded over time and somehow disrupted the infloor heating line (this was offered by one of the plumbers). Either way, the increasing leak in the in floor heating caused the floor to settle more. Meanwhile, the liquid from this leak found a way up between the slab and foundation, and started flowing/pouring/dripping between the foundation top and the lumbar wall footer.

Still, I don't know yet how this happened. My measurements are ongoing. Both so I can understand what the actual damage is before I start throwing life-changing funds at this, and to see if I can plausibly come up with a causation that insurance will cover (I have the most comprehensive coverage possible, except earthquake I think, apparently I am covered for bear attack). Is it possible that the in floor heating gave way, sunk the slab a bit to worsen the leak worse, this leak got between the wall lumber and foundation top and softened their attachment so that the wall could relieve some stress by RISING off the foundation? Could this all be just seasonal change and as I watch and measure I might see this ebb and floe but stay stable over time (afterall I have always noticed the doors are hard to close in the summer and always easy to close in the winter)?

Any wisdom or super-sleuthing suggestions you can offer are greatly appreciated and warmly welcomed.

John
 
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You need to abandon that section of in floor heating.
You can re-pipe that zone into radiant flat panels, with a blower if needed, which I would.
Blower is very quiet, panels are very low profile and classy, no ugly baseboard rads.

Then hire a structural engineer to figure out what is lifting, settling, or sliding.

Maybe underpinning can hold your house up on that slope?

And repair any gutter or drainage issues first, that stray water is just lubricating the slide down the hill.

https://www.archtoolbox.com/representation/geometry/slope.html
 
Thanks Jeff. I really appreciate your input.

For clarity, the house is at the top of the slope so only a small portion of the house is actually "on the slope". That said, the evestrophe downspouts got all replaced today. I just got back from the house, where I revised my measurements again. I am planning on running a series of measurements to see how this all varies with time and temperature. As for the infloor heating, my wife and I were thinking of replacing the faux-wood with real wood anyhow. Having run a jack-hammer in the past and did alot of manual chisel breaking of concrete in the past, I might still have an opportunity to get into that floor and repair the loop. The plumber/boiler people are going to bring in an infra-red camera that apparently will show the pool around the leak when we open it for testing. Hopefully that will really limit the portion of the floor that needs to be accessed.

But, regarding the measurements: it seems the low point in the foundation is also right where the foundation moisture was. This low-point actually forms a bow in the foundation wall. I am starting to wonder if the in floor heating liquid softened the lumbar so it could pull off the foundation to relieve stress in the material, causing to it to pop up. If that's the case, it might be just a situation of shimming up the wall for support, cosmetics (crack fill, repaint), reach a final solution on the in-floor heating (repair or isolate) and hopefully Bob's my uncle.

Of course, I recognize that this is me starting to sound like I am in an echo-chamber. But, like I said, I will keep on measuring and assessing, before I decide what needs to be done.

Continued input is greatly appreciated.
 
Unless you are building on a flat plane, any slope under or next to your house will influence gradual earth movement.
And the structures above or near that slope will react.

Slopes want to slide or slip until they are level.

Water helps that process along.
 
I think you have the right approach in weighting and measuring over time. If you can prove it has stopped moving the you just open the wall and add support in one way or another to the lower foundation issue.
The floor can be brought up to level with foam jacking, you would need to have the heat in the floor mapped but that can be done with the IR camera.
Under-Floor-Heating.jpg
 
Ah, the plot thickens. It turns out that we had an earthquake in the region while I was gone in the summer on holiday that did cause damage to some properties. Then, when we got back is when I started noticing the odd behaviour with the boiler/in floor heating. So, this chain of events was quite possibly set in motion by changes in the floor slab position with the ground shake. At least now I have a legitimate causative event. From this all other things can fall into place.
 
Unfortunately I know my insurance won’t cover earthquake damage. At this point I think I am going to spend the winter sighting levels and measuring everything, again, and again, and again. I am going to also spend that time learning what I can about all of this stuff. If I notice little changes I will continue to observe and learn. If I notice big changes I will panic and spend lots of money LOL. Over the Black Friday weekend I was able to get a great deal on a flir infrared camera. Better than bringing in the boiler people to do the readings. I have strong suspicions where the infloor heating is popped. If my camera confirms this and I see no other leaks (and really there should be only one leak as this stuff had propylene in it and the place has never froze)...then I will pull out my diamond blade grinder and diamond blade circular saw, cut the trough, repair the line, pressure test it, get the boiler people to come in and confirm my work, then patch the concrete. During that time I will drill (something like 1/4 to 1/2 inch bit) straight through the slab and put an inspection camera under it. I guess I will learn what happens after that. Hopefully it will be “just patch the hole”. If I see a big space there then I guess I am talking to people about pumping concrete in there? Or is there some other hard setting expandable foam that has been invented for this?

Then after the winter, continuing my measurements into the thaw, I will see what is happening. If the foundation is stable then I am not going to touch it. I suspect I might still want to confirm the integrity of the lumber at the foot of the walls though (cut out the drywall that is usually hidden by the baseboards and get an inspection camera in there).

I am still struggling with why that wall seems to have lifted in one spot, where one would have initially expected the foundation to drop (but it didn’t). I am starting to think I might have to slightly lift the walls where they “haven’t lifted” to match the walls where they “have lifted”. But this will be strongly dependent on what my inspection camera tells me. Also, lots of learning there. I can probably pick up 4 bottle jacks, 8 tonnes each, for a hundred bucks. The trick is to learn what I am doing first, go slow (like lift it a 1/2 - 1 inch over a month, completely dependent on how the walls/house respond) and be 100 percent certain of what I am doing before I go and collapse the house or break all the glass.

Of course I am writing this largely to see reactions, to help guide my path of learning and discovery on this. Please know that I have no intention of jacking any walls until I am certain I have mitigated every risk and faulty thinking that could happen before then.

Cheers

John
 
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