Pouring the Footings

The Video:

The Story:

These things usually start early in the morning…  This morning, we were all ready to get these footings poured without any of the usual last minute running around.  Three concrete mixing trucks were waiting at the bottom of the drive way as a dozen guys from Dysert Concrete arrived.  The concrete pump truck arrived and while it setup, the guys were walking around and scratching their heads about my strange layout.  Some were even taking pictures with their cell phones.

I showed some of the guys where the garage formwork had been done incorrectly and they started figuring out what to do.  I was nervous because the first few guys clearly had no idea how to mount the groove form…  But then a guy showed up who clearly knew what he was doing and took over organizing that work while some of the other guys got to filling the other forms with concrete.

The concrete mixer trucks dump their concrete into the back of the pump truck.  The pump truck comes equipped with powerful pumps that can push the heavy concrete thru its 135 ft boom.  The operator has a remote control box and walks around with a few of the of the concrete guys to control the movement of the boom and the flow rate of the concrete while they guide the end of the pipe along the form. It is quite something to hear that concrete falling down thru the pipe.   For a big job like this, the pump truck really is worth the money.  The alternative would have been trying to position the mix trucks around the site and push or wheelbarrow the concrete to the inner parts of the forms…

Initially, they overfilled the forms.  The thin lap siding formwork was not strong enough and started to give way and lean out.   I guess there were not enough stakes in the soft sand to hold back that much pressure.  And after that, they filled the forms only half way and gave it some time to stiffen up a bit before coming back for a second pass.  After the forms are filled up, they simply screed them off.  It was amazing how the weight of the concrete pushed out even the 2×12 boards.

2014-09-29_Footing

Meanwhile, the larger group were still working to properly finish the groove forms for the garage.

2014-09-29_FootingsGarage

By the time the form for the garage was ready, they had already finished pouring the footings for the rest of the house.  They started by filling the perimeter of the garage footing.  They gave that a little bit of time to stiffen up because this was 18 inches thick and even more likely to blow out.  While they waited, they pushed in vertical pieces of rebar along the middle of the floor to mark the floor slope.

Eventually, they started filling up the slab area, but quickly ran out of concrete.  Another whole truck arrived and they dumped it out, but it didn’t go too far either.  Along the way, they were screeding off the surface with long poles and leveling the concrete against the side of the forms and the rebar pegs in the middle.  On the right side of the below picture, you can see the power screed that they used.

2014-09-29_FootingsGaragePour1

I noticed a slight bulge were my radiant floor pex tubes went under the concrete.  I pointed it out and they said that it must be floating up.  They said I should have tied it down every 8 inches…  I thought that they (as experienced professionals) should probably have checked that before starting.  Anyway, since we were waiting for the next concrete delivery to come anyway, they just gave the concrete a little time to stiffen and then pushed the pipe under (using long sticks) and pulled concrete (screeded) over it.  I was still very nervous that it was still too close to the surface, but they told me it would be fine.  I didn’t think until later that I could have put a piece of that 6×6 inch welded Wire reinforcement over the pex pipe to make sure that it stayed down…

Another truck load of concrete arrived and was pumped out.  This time my concern was that the 6×6 WWR (Welded Wire Reinforcement) had been stamped down too much, especially at the front of the garage.  Like the rebar, this welded wire reinforcement needs to be fully encased within the concrete to do its job.  It doesn’t do much if it is trampled down under the concrete.  I had been pestering the guys to try to pull up WWR elsewhere, and they made some halfhearted attempts upon each request, but at the front of the garage, where the slab sloped to the full 18 inches thick, it was so trampled down that I concluded it would be hopeless to ask them to pull it up…  Instead, I waited until they got the got concrete in, and then I brought over two more big pieces of WWR and laid them on top before they guys had a chance to screed things over…  Hopefully,  these additional pieces stayed within a few inches of the surface where they could do their jobs.

With only one little corner left to go, they sent the pump truck home and we waited for the last concrete mixer truck.  Most of the crew left also, except for two guys who were going to hang around and do the finish work on the slab.

2014-09-29_PowerTrowel

After the last couple yards of concrete were in place, the senior guy used a power trowel to work the surface.  The younger guy got busy working on removing the wood that held the groove form in place.  Since things were now setting up quickly, my family and I rushed to press our hands into the stiffening concrete.

They took the power trowel over the surface 4 separate times and did a pretty good job there and on visible edges of the slab.

All in all, the footings and garage floor took 78 yards of concrete.  The guys put down about 1300 lbs of rebar in the footings and I added another 530 lbs in the slab floor.  That is just shy of a full ton, not including the fourteen 16×8 sheets of 6×6” WWR.

They came back the next day to remove the forms and cut grooves in the concrete…  However, they didn’t want to cut up in the area where the radiant pex tubing had floated near the surface.

Mistakes:

On the whole, the footings turned out pretty well, and I appreciate that Dysert concrete was even willing to take on this job (many other companies didn’t even call me back after seeing the plans).

However, as a first time General Contractor, I made some mistakes here (just like every other phase of construction).

  • I should have checked those forms better. As the rule of thumb goes, “put as many stakes as you think you need, and then add a couple more.”   We didn’t have enough stakes in many places, especially on the bedroom side where the sand is softest.  The bulges are a bit ugly, and they wasted concrete (more volume than needed).  In one spot where the form leaned out, it actually affected the surface level of the footing and may give me a bit of a headache later…  Oh well, at least these footings will be buried and never seen again.  They don’t need to be pretty to do their jobs well.
  • I did ask one or two guys if the pex tube that I placed looked right, and they just gave me a nod and a grunt… I should have got someone to check my work more closely.  Then they would have seen my mistake (not tying them often enough).  Things would have been more secure and I could have properly cut the slab to prevent cracks…  As it is, I have 3 long (thin) cracks across the uncut portion of my slab…
  • I should have complained about the level for the grove form.  I saw that the east side sagged a bit in the middle, but I thought it would float up or be taken care of some other way…  I didn’t say anything and now I need to deal with water pooling in that area.  It won’t matter when I am finished the Quonset and grout the groove, but in the meantime, it is annoying.  If that water freezes, it could cause damage.  It could also rust the bottom of the Quonset steel before it is grouted…

 

Generally speaking, you need to speak up about concerns and get them addressed before the concrete gets poured… It is too easy to get swept up in the frenzy when there are so many things happening on the site.

Prepping the garage slab

The Video:

My time-lapse camera is pretty basic and has a manual focus.  I had it set to 8ft instead of ∞.  Easy mistake ;^).  But here is the slightly out of focus video anyway.

The Story:

I was not able to be on site when the crew setup the formwork and rebar for the garage slab.  When I did see it, I realized it would need to be redone.  Engineering had been done by 2 different engineers…  The first was the engineer that I had hired to do the entire project.  He specified rebar every 24 inches across the slab.  The engineer from SteelMaster specified 6×6 WWR (welded wire reinforcement).  I decided to do both.  The guys who assembled the footings were only looking at one of the drawings, so they just put down the WWR. In addition to adding rebar, I wanted to add a vapor barrier, rigid insulation and radiant floor pex also…

First, I waited for the plumbers to come and do their work roughing in the garage bathroom.  While they were working, I removed the large sheets of welded wire reinforcing and bent 40 peices of repar to put into place.  After the plumbers were done their work, I tried laying it all out myself.  However, I soon realized that positioning 16×8 ft sheets of welded wire is really a two man job.  I decided to phone a friend.  Aaron was willing to give me a hand early Saturday morning.

We started by excavating away a couple inches of sand in the areas where we planned to place the rigid insulation.  At nearly 27$ per sheet, I didn’t want to insulate the whole slab, but I did want warmer feet in the bathroom and workshop areas.

We cut and laid the insulation carefully around the plumbing for the bathroom. And then in an “L” shape where my workbench would be…

Then we unrolled a 20ft wide sheet of 6mil poly to use as a vapor barrier under the slab and under the footing all the way around.  Here, we are lifting the rebar in the footing to get the plastic underneath it.

The poly sheet was 20’ wide, so we had to do this in two overlapping pieces… Which Aaron taped together.

Initially, we had rebar chairs down the middle, but they were too tall so we had to remove them later.

I measured out and marked the 24 inch intervals for the rebar using surveyors paint.

Then we laid the rebar, using small bits of insulation as spacers.  We put the 6×6 WWR on top of that.

Lastly, I brought out some pex pipe for future radiant floor heating…  The pex was much longer than I needed for the bathroom, so I made a last minute decision to swing a loop out past my workbench…  I secured it to the Welded Wire Reinforcement ever few feet.

The last thing that needed fixing was the wooden board that had been put in place as a keyway for the quonset hut.  It had been installed too shallow and had been put in the wrong place (even though I had clearly marked where it should go).  We decided to let the experts fix that mistake on the day of the pour.

The Mistakes

  • Perhaps I should have excavated a bit more before placing the rigid insulation. It seemed OK at the time, but after adding spacers, rebar, WWR and radiant tubing, I wished I had it an inch deeper.
  • I may regret adding the pex loop thru the shop… It may end up making it difficult for me to heat that bathroom adequately without also wasting heat in the shop.
  • I only tied off the pex every few feet. But later, when we added the concrete, many sections floated to the surface.  The crew pushed it back down again, but then later they didn’t want to cross cut the back half of the shop.  Of course, cracks formed along  where the PEX tube was too close to the surface.

Forming the main floor footings

The Video

You can find the video here:

The Story

The day started early, with the site mostly staked from the previous day (that video was not very interesting, so I won’t bother posting it)…

But we still needed to place a few more stakes, so as the morning fog cleared, Sherri and I finished what we had started.

We were in a rush, so our precision was not the best, but the footings are 2 ft wide and the wall is only 6 inches wide, so we just wanted to get things within an inch or so (further fudging happened when the forms were actually placed, I hope it all works out)…

The guys from Dysert Concrete arrived and started working on forming the garage while we finished up the stakes on the south side of the house.

The garage perimeter required about 200 linear feet of boards.  The plan is to pour the garage footing and floor at once (sometimes called a thickened edge slab).  The perimeter is 2 ft thick and 18 inches deep (shallow frost protected footings), but the middle is only a 4 inch thick slab.  So we would need to dig trenches around the perimeter and then also backfill and tamp down the middle.

2014-09-17_FootingsPrep

The rest of the house looks curvy, but actually it only needed 350 ft of curved boards and 400 ft of straight boards.  They used 2x12s for the straight boards and the flexible ones are half inch thick lap siding.  Actually, it seems like modern builders only use lap siding for curved forms, never for actual siding. The bedroom side of the house is mostly straight boards, with curves on the end and back (against the earth).

People assume the curves add to the cost, but actually, the lap siding costs much less than the 2x12s and the curved walls resist the earth loads better, allowing me to use 1/3rd the thickness and less reinforcement.

2014-09-18_CurvyForms

These are just the footings.  Basically, the walls will sit on them and it will help to distribute the loads so the house doesn’t sink into the sand.  They will end up one foot below the floor and will never be seen in the final house, so the exact angles and curves don’t really matter that much.  So, when the inside radius of the bedroom apse was just too tight to curve the lap siding board without breaking it, we just went with piecewise linear…

As they started leveling the tops of the footings, it became clear that we would need bring up the ground level a little, especially on the bedroom wing side of the house…  I used my skidsteer to dump some sand near the right places.

The next day, they continued with leveling the forms and moving sand around to meet it.  I actually needed to get a bit more sand for them.  They use a builders level to set the boards to the right height and then screw them to the stakes.  After the boards are screwed to the outside stakes, they can remove the inside ones.  Then they push sand up against the outside of the forms to help resist the lateral force of the concrete.  It worked in most areas, but it later became clear that they should have used more stakes in some areas to prevent the concrete from moving the boards.

After leveling, they ran the tamper thru the area to pack it all down so it won’t settle later…  Then they set the rebar chairs (that will keep the rebar out of the dirt).  At this point, we had an issue because they had brought 6 inch rebar chairs because they assumed I would want the rebar in the middle of the footing. But since most of the tension would be in bottom of the footing, I needed them to push those chairs half way into the ground.

Eventually, they cut, curved and placed about 2000 ft of rebar.  Actually, I had ordered much more rebar than I needed because I figured I would use it eventually.  I was very happy to be able to use my SkidSteer to unload the two large bundles from the top of the truck.  I am sure Doug’s guys were also happy that they didn’t have to unload it.

2014-09-24_FormswRebar

The Mistakes…

As per usual, I am sure I made a number of mistakes.  Many will become known as I move ahead with the project, but I know of at least a couple already.

  • I was busy working that day. I was short on vacation days and only took half the first day off and none of the second day.  This means I couldn’t guide the crew.  Instead, they relied on my stakes.  I had placed the stakes fairly carefully, hopefully within an inch or so of where they should end up, but the guys simply measured off the stakes and cut boards without concern about matching lengths or square angles.  If I had walked with them, I could have said “this board is 6’9” long and so is the one opposite…”   It would have resulted in a more accurate footing…    On the other hand, the footing will be buried and doesn’t need to be perfect to distribute the load adequately.   There was actually a 3rd day, but I couldn’t make it out to the property at all that day and they really didn’t understand what was needed for the garage footing, to the point that we had to redo it (fortunately, I did not have to pay by the hour).
  • My plans were changed by an outside force and I didn’t properly adjust my 3D model or work thru all the ramifications. The change started when the basement was dug and we excavated a wider area than I expected.  This caused the inspector to require that I added those pilasters to help support the footings that spanned the backfill.  We also made a change so that the garage floor and footings were poured at once, and therefore the top of the garage footing was the same level as the final floor.  And since I needed the footing to sit on top of the basement wall, I put the mud room footings at the higher level all the way across from the garage to where they sit on the pilasters.  I thought about how this would affect the concrete rib that will sit on that footing (I will need it to be a foot shorter than the others.) but forgot that it would also affect how the floor is poured and would also complicate how I insulate that footing.  Oh well, I will deal with that when I get to that point.

Septic Field

The Video

This is probably the shortest video I have made so far.  I didn’t need to be on site for most of this work, and only caught a bit of it on video.

The Story

After digging the trench and placing the septic tanks, we had some delay while the health department decided how we had to deal with our unofficial garbage dump and steep sandy terrain.  Basically, the Roe Brothers dealt with most of that, so I didn’t catch all the details.  It seems like there was a switch of health inspectors to deal with and the second guy didn’t like the way we implemented the first guys plan (or something like that).  There may also have been an additional inspection, but we were already way over budget, so the Roe brothers ate the cost of that one (several hundred dollars per inspection).

We were also waiting for gravel to be delivered.  My soft sand and large gravel order meant that only a certain kind of truck could manage the delivery without getting stuck.  Only a few gravel yards in the area had the right kind of truck and all were broken down or otherwise indisposed.  There was also a power outage in the area (due to a crazy storm) that prevented some of the gravel yards from loading up their trucks, so orders were backing up.

But eventually, after weeks of delay, 60 yards of gravel arrived and the Roe Brothers were able to finish the septic system.

Basically, the effluent will flow out of the 2nd septic tank and into a PVC Manifold that separates it into 7 parallel pipes… These pipes have little holes that will let it leech out, basically spreading it wide enough for nature to absorb it by natural processes.  On the other end, the 7 pipes are reconnected by a manifold (for some reason)…

Later, the pipes and gravel were all covered over by dirt, which Dick Roe had to sculpt for proper surface flow around the septic field.  That area should end up pretty fertile.

The 70 year old garbage dump magically disappeared, presumably its “antiques” (mostly old bottles) were reburied near by, but I forgot to ask where.

Then Sherri (with a little help from the boys) seeded tens of thousands of square feet with a rye/blue grass mixture and raked it all under.

In the end, we went about 8% over budget on the septic field.  I also had not properly factored in all the costs associated with back-filling the long trench and around the house, which added a couple thousand dollars extra and put us about 30% over budget on the total septic system.

Next: we get going on the main floor footings.

Waterproofing Test

Invisible

Yes, our waterproofing is invisible…  Not just clear like I expected from the description on the bucket, but actually imperceptible.   You can’t even feel it.   So we were not that surprised when our building inspector questioned it.

ProteShield-5-Gallon-REDUCEDWe had used ProtéShield made by New Look International.  Actually, we bought it from Home Depot. Our shotcrete walls are curved and not the smoothest in the world, so it was important that we use a waterproofing that we could spray on.  ProtéShield claimed to be, “a water-based inorganic elastomeric polymer sealer designed to penetrate, waterproof, seal, and protect various porous surfaces.”  The website said it was, “Recommended for sealing, waterproofing, winterizing and protecting most porous building materials such as concrete, pavers, concrete block, brick, precast concrete, plaster, drywall, GFRC, gypsum board, stone… [etc.]”  The brochure listed, “Ideal Interior and Exterior Applications: ” including, “basements and other below grade spaces.””Foundation walls (above grade and below), bridges, sound and barrier and retaining walls, fencing, towers, buildings.”  Their technical data sheet claimed ProtéShield would protect the concrete against, “ultra violet rays, ice, water, chlorinated water, salt water, rain, acid rain, salts and other chlorides, rust, mold, fungus, insects, chemicals, oil, fuel, stains, and excessive temperatures.”   The cost was about $270 per 5 gallon bucket and I would need 2 buckets to get the basement walls done.

So, when my building inspector questioned it, I brought out the empty bucket and showed him what we had used.  He said he had never heard of it and would need to see the official test results.  No problem, I emailed him the technical data sheets (Sherri found them with her new smartphone).  He gave us a partial approval on the waterproofing and said we could proceed with the back-fill at our own risk.  He would check out the data sheet, but if it had not been properly tested, we would need to fix it (dig it up) before proceeding with any other steps.  It was a tough decision, but I was sure it would pass and the excavators were due to arrive any moment to work on the back-filling.  We went ahead with it.

A couple weeks later, my building inspector emailed me that the correct tests had not been done and we were not approved for backfill…  I called New Look International and asked them about it.  They said they had never been asked for that test before but insisted that they test their product and it would work for me as described.   They called the building inspector to talk to him on my behalf.

Test and verify

The next day, the building inspector called and told me about this part of the building code…

R104.11.1 Tests. Whenever there is insufficient evidence of compliance with the provisions of this code, or evidence that a material or method does not conform to the requirements
of this code, or in order to substantiate claims for alternative materials or methods, the building official shall have the authority to require tests as evidence of compliance
to be made at no expense to the jurisdiction. Test methods shall be as specified in this code or by other recognized test standards. In the absence of recognized and accepted test methods, the building official shall approve the testing procedures. Tests shall be performed by an approved agency.  Reports of such tests shall be retained by the building official for the period required for retention of public records.

He said that he would allow me to conduct a test of the waterproofing to establish if it was acceptable or not.

I designed two tests.

My first test was based on other damp proof tests I found on YouTube.  These tests place the lower end of concrete samples in water and see if it is drawn up into the sample.   I used pieces of shotcrete that had ended up stuck to my bracing.  I waterproofed half the samples and made this video.  I think it worked well in this test. (no music because testing is serious ;^)

Then the second test was against gravity… I made two concrete bowls from ready mix with fiber reinforcement. I waterproofed one and then filled both with water. The hope was that the one would hold the water without letting it soak in or drain thru. Clearly, the waterproofed bowl did much better than the other bowl, but, perhaps due to the small bubble holes on the surface that did not get properly filled with waterproofing, water did leak into the bowl (the water level dropped). Here is the second test video.

Conclusion

I sent both videos to my building inspector and he approved the “damp proofing” on the vertical basement walls. That was a big relief because it would have been expensive to dig it up and reapply.  However, he didn’t feel comfortable calling it waterproofing for the horizontal roof of my earth sheltered building.  I agreed to use a more visible waterproofing for that.

On to the next challenge…