De Basement

On Friday Jul 12, forms went up. Actually, first they went down, slid from truck to hole along one of the same 2x12s that were used to form up the footer.

The forms are a pretty clever thing – they have both holes in the top and bottom flanges to allow them to be stacked and linked (my walls took two 4′ courses) as well as holes through that allow for breakaway ties that connect them against the weight of the concrete pushing outward when they’re filled up.

Originally, they were planning to pour the same day, but between the availability of concrete trucks, the length of the process, and the heat, they wound up calling it off and rescheduling for Monday. Thus, on Saturday Jul 13, I had a chance to check the work, which seemed great overall. I also took a number of photos to provide to our local Code Enforcement Officer, since he was out during the week and wasn’t able to visit the site between the forming and the pour.

I verified a number of things like the distance from the lot lines, which all seemed OK. I did find a pair of pipes (for utilities) that were on the wrong end of the wall, but I was able to easily put in another pair. The two grey pipes are the ones I added.

However, by the time I was done my clothes were covered in the release oil that they had put onto the forms. Even though this was an “eco-friendly” release agent, it smelled so strongly that Raederle had a migraine within 15 minutes and I promptly tossed the clothes in a pile outside.

On Monday Jul 15, they came back in the morning to do the pour. As much of the work (which is a lot) is done by the concrete truck, the team still had to stir and push the concrete away from the chute and into the forms with long 2×4’s. It was a hot (80°F/27°C) and sunny day, but not yet the peak of the week.

For the end of the pour, they used the very clever “conveyor truck” which allows them to direct the concrete just by moving around a long tube. That let them focus their efforts on the finesse of getting it level so they could finish the top surface easily.

Then they installed the anchor bolts that will hold the house down to the foundation.

Here is what it looked like at 8pm, several hours after they finished, as the concrete was setting.

The next day, Tuesday Jul 16, they were back to take down the steel forms. Here is what it looked like partway through at a little after 10am.

Those steel forms that were easily slid down into the hole then all had to be lifted back out and loaded onto the trucks. A lot of hard, hot, and thirsty work, on a day that got up to 88°F (31°C) with bright sun all day. I brought them a gallon of ice water mid day when their own reserves were running low. And here at last, is the finished product. I now own (well, once they cash the check) a basement!

Set In Motion, Set In Stone

Today was a big day for the Little Rental House. Today was the day when it became rather more difficult to get cold feet and quit. What was just a hole in the ground yesterday is concrete in the ground today. The footers were poured. On Friday, they expect to return to build and pour the basement walls.

Today was perhaps the hottest day of the summer so far – something like 92 degrees Fahrenheit with high humidity, so I do not envy the team who came out to do the work, despite their bronzed skin and 6-pack abs.

A few interesting steps occurred along the way. First of all, as they were setting up the forms, they asked me to order a load of stone (“Crushed Number 2 Gravel” looks something like this, although I got it from H.L. Robinson which doesn’t have pretty pictures on their web site). They spread this on both the inside and outside of the forms to support the weight of the concrete. Second, I got the first formal building inspection from the Town of Danby, when they came to review the installation of the rebar inside the forms before the concrete was poured. They included the new NEC mandated ground connection to the rebar, where an extra piece of rebar was bent so that it protrudes out of the footer to provide a place to make a ground connection.

When the truck arrived to do the pour, they had to move around the chute of the truck, and an auxiliary chute that they used kind of a little “marble run” game to redirect the concrete to various areas. They would then push (with shovels) the concrete to get it spread out evenly from where it was being dumped.

One fellow generally worked with the concrete “float”¹ while the other was working with the truck and pushing the concrete level. They would also sometimes stir it up by rapidly inserting and removing the shovel, which helped to get it to flow and self-level. (It’s not clear to me whether they were taking their level more from the nails in the forms or from the concrete’s own natural flow.)

They were also going around inserting the vertical rebar which will tie the walls to the footers. They told me that with 3 people they could generally keep up with the truck’s pour, but with just 2 they were having to switch off jobs and had to stop the truck for several minutes at a time while they caught up. Nevertheless, the whole pour was only 1h40m of the whole footer project.

The last part of the pour they had to do with the wheelbarrow (I believe I counted 8 loads), because the reach of the truck’s chute wasn’t far enough, and their own extension chute had a broken chain so they couldn’t attach it to extend the fill the remaining distance. But pretty quickly, the pour was finished and smooth. Because of the heat, it was already starting to set up by the time they got around to making the two ends meet.

So, if I’d ever considered having second thoughts about embarking on this project, I think the time is now past. We’re building a house!

I searched google to try to figure out where that name comes from, but didn’t find any good answer. ↩

Making Plans – The Road Ahead

I’ve decided to upload a full copy of the plans for the Little Rental House, for those who might be interested in seeing more details. When I was first designing, I found that most house plans out there were behind a paywall. Since I drew these plans myself, there isn’t any reason I can’t share them with the world, but if you find them useful I’d be happy if you wanted to make a donation that you feel reflects the value you’ve gotten from them.

I’m including some notes below, and as I have time to write up more aspects of the project, I will try to update this page with links to more detailed posts.

E – 1: Elevations

The original design work was done in an extremely old 3D Home Architect (version 10) from Punch Software. While it has plenty of limitations and occasional crashes, the mere fact that it still loads and runs under Windows 10 is so gratifying that I’m willing to put up with a few glitches. This allowed me to trivially create the 3D renderings shown on the first page. They’re pretty, but they don’t necessarily communicate the technical details needed for construction.

F – 0: Basement

I’ve written about the choice to include a basement in this blog. The elevator speech I give people when they look at the big hole in the ground and say “oh, it’s going to have a basement?” is: Well, yes, but it’s really just for mechanicals. It turns out it’s about the same cost to build a basement where I can do the other work myself, as it is to build a slab and hire people to do all the work that has to get done perfectly the first time before concrete is poured. Plus, it allows me to add some features like waste water energy recovery that I wouldn’t have room for otherwise.

On the technical side, I’ve elected to go with cast-in-place walls for cost, making them 8″ thick so there is plenty of “bearing space” for the I-beams that constitute my floor supports. These will run underneath the SIP flooring to provide a relatively low cost and low labor support structure that will prevent floor sagging. I may at some point share some of the details of the engineering calculations for the beam strength here, but the short form is that spanning 24′ with wood would require huge timbers or manufactured wood beams that are much more expensive and not much more renewable than iron, and splitting the distance with a single 27′ beam and 12′ joists would have more susceptibility to the kind of “droop” that I’m experiencing in my own home, where doors need to periodically be adjusted so they latch properly. It seems like steel beams are rarely used in residential construction, but I’m not entirely sure why not.

I explored the use of precast stairs, but found out that the maximum opening they would allow is 39″ wide, which would significantly limit the size of tanks and other items I might want to move into the basement. It would also potentially need to be longer than the 6’4″ shown on the plans, which would make the stairs at risk of coming too close to the lot line. Bilco’s standard “Size C” door will allow for a full 4′ wide staircase, which I’ll then have to build.

F – 1: First Floor

Because I’m building an accessible home, all the living areas are on the first floor. Two bedrooms of 100 sq feet take up the east; an accessible bathroom is centered on the north wall; a large living/dining room area is at the southwest, and a small galley kitchen begins just after the front entrance at the northwest.

The layout optimizes the appliances that need water and drains (kitchen sink, bathtub, bath basin, toilet, and clothes washer) within a very small area, which will reduce the heat losses for hot water and the overall plumbing materials cost. The stove is at the outside edge to allow it to be directly plumbed with an external propane tank.¹

F – 2: Second Floor

This floor represents an L-shaped area of extra floor space. It won’t be accessed by stairs, but rather by a ladder of some sort. Some might choose to use it for storage, others as a play area for kids (it will have a railing around it), and others as an office. Because it’s not accessible like the first floor, I didn’t want it to have any necessary functions, but getting a good roof slope for solar more or less automatically produces a space here and I thought many would find it useful. There’s a small area at the southeast that is so low (below head height even for kids) that it’s not useful floor space, but some mechanicals (such as a heat-recovery ventilator) could conveniently be installed here.

M – 1: Electrical

This sheet shows the placement of various electrical fixtures on the first floor. It includes the placement of various low voltage LED lights, low voltage (24VDC) electrical outlets, and the conventional 120V outlets and switches as required by code. What it does not specifically cover is how the outlets and switches are wired to two different service panel – a primary 150A service panel and an auxiliary smaller (probably 60A) subpanel for “critical loads” which can be supplied from a solar battery bank inverter. I’ll write about these details in a separate blog post.

S – 1: Sections

These fun little details show cross-sections of three portions of the design: the roof, the basement wall and first floor, and the slab/footer. The roof details show how the different layers of insulation (which together add up to approximately R-53) are installed, which prevents condensation within the cellulose insulation. The basement wall details show the relationship between the footer, footer drain, basement slab, wall, backfill, I-beams, SIP flooring, and SIP walls. These details help identify how the structural components work together and also identify particular elements which need to be purchased and installed such as the “mud sill” and “rim joist” boards. Finally the slab/footer NEC detail reflects the (relatively new) requirement that portions of the foundation which are in electrical contact with the ground must now have their own ground connections, in addition to the normal requirements for grounding rods.

W – 1: Schedules

This shows the window and door “schedules” that list the particulars of the windows and doors to be installed in each location. Although I’ve listed preferred manufacturers here, this piece of the design isn’t 100% set in stone as the availability of different windows from different companies seems to vary a lot over time. One of the key elements is the fact that the bedrooms must have “egressible” windows with a significant clear area (5.7 ft²) through which residents can evacuate and/or firefighters can enter. In addition to the mandatory egressible window in each bedroom, I’ve also included one “E1” window in each bedroom, which meets the requirements only on the first floor (clear area 5.0 ft²).

N – 1: Notes

This page covers a lot of technical details which are better stated in text than in drawings, ranging from the general “do the work according to code” to details like the structural lumber stress values and the requirements for smoke and carbon monoxide detectors.

I’m not thrilled with the use of propane, but it provides a backup in case electric energy winds up being in short supply. At present, propane is produced in surplus as a side effect of oil drilling, and when there isn’t a market for it, it is often flared off. So by using it I’m choosing to put that heat somewhere useful instead of making it a waste disposal process. ↩