Yep, I'm a glutton for punishment and this project confirms it.

The fence project was a haul and it was not easy, but it did challenge me and help me learn some new skills.

The same client asked for a creative solution for a greenhouse, but NOT your standard greenhouse. No kits, nothing plain jane, it needed to tie into the aesthetic of the fence along with the typical functionality of good greenhouses.

OPTIONS

running water

gas heat

automatic louvered ventilation

automatic electric ventilation

30A electrical, dedicated with GFI

heating cable in the ground for bedding in plants or seeds

This is the process for getting this project completed.

LOCATION

The placement of a structure like this is very important. If the greenhouse is exposed in an area where light is in abundance, you will have a ton of solar energy to utilize or to contend with (Remove) in certain situations. If you have poor lighting, then you need to consider increasing insulation components to trap and hold heat (thermal mass) or other energy-consuming methods to retain heat.

Finding a mix or balance of sunlight and shade through the growing season is an ideal situation to be in. Let me explain a bit more. If you do bonsai and the greenhouse is for extending the growing season, overwintering trees &/or getting a jump start on spring with repotting etc., then the situation needs to be treated like this (at least in Idaho)…. Keeping the greenhouse cool is going to be the biggest challenge. I know this seems odd, but think about this scenario… it's January, the outside temp is 25 degrees in the morning and by mid day will be 35 deg. It’s a clear day and the greenhouse is sitting in mostly sun throughout the day. The doors and vents are closed, and trees are hanging out inside. Let's say 60% of the surface area of the greenhouse is comprised of clear panels (any type - poly hoop or double/triple wall flat panels) the inside temp by 10 am will most likely be 60deg or higher and by noon will be pushing 80 to 90 deg. In Idaho, we typically have about 300 days of sunshine annually. Keeping the greenhouse ventilated becomes a HUGE concern when trees "TYPICALLY" start to metabolize around 42 deg when paired with daylight length and a few other factors. SO, what happens to many hobbyist is they get a kit and then their trees start pushing new foliage or getting fleshy growing tips in Dec for the coming year and they have to then go into PANIC mode trying to keep the temps up during the coming coldest months (Jan/Feb).

To combat this, I have learned that in IDAHO, fewer clear panels are required to properly light a greenhouse and more solid panels help provide a more consistent environment for overwintering and gently raising the temperature in the spring. Avoiding dramatic spikes and drops in temps is important for our plants.

FUNCTION

Here is my list of important functions of a proper greenhouse

Solid construction with the ability to withstand seasonal winds/storms

Proper size for the application - height as well as footprint

Ventilation - ability to move air or cycle fresh/stagnant air as needed

Access - appropriate sized entry/exit

Utilities - water, power, heat, cooling

Aesthetics - needs to look the part it is playing in your environment

DESIGN

There are fifty ways to Rome. Some greenhouses are utilitarian and designed for pure functionality. Some are ornate and made with premium finishes for a display piece. Some for blending into an environment or neighborhood garden. We all know they come in infinite sizes and can be made out of thousands of materials, your imagination is your only limit here.

This greenhouse was designed to mirror the look of the house or at least elements of the house. The client's home has an English Tudor meets mid-century modern-ish feel to it. I redesigned this structure ten times for the client, yep… ten times… That’s patience.

The greenhouse would be positioned under a very large maple tree on the east side of the property. The design incorporates a 12-foot tall scillion roof with a low slope on a 12x16 footprint. The peak of the roofline is off-center showing a larger section of roof towards the east and allowing the louvers and angles to face the house. There are two thoughts about this decision, the first is that the owner can see if the louvers are open and gauge temp with a quick look and see their positions. The second, is the angles have a more impactful appeal to them from the house in this orientation.

The ends of the structure on the north and south walls are flat without an overhang. This simplifies the design and also the engineering of the roof. The bottom panels are 10/20 steel that echoes the fence tops. This acts as sheeting reinforcing the structure and integrity of the bldg. For added fun the steel is a durable material (obviously) and it feels industrial, it looks great and pulls in the colors around the property well. The rust gives a feel of age or patina, this pairs well with bonsai and offers another piece of canvas to build on if the owner decided to use the structure as a backdrop for displaying trees or planting things around it.

In addition to the framing, steel roofline and footprint I opted to go with 8mm double-wall poly panels with "H" and "L" panels for the expansion joints. This was something I chose to do as an improvement out of my own profit (and it was substantially more than the recommended 4mm or 6mm options). I did this because, if it was my greenhouse that's what I would do. When quoting the project, I didn’t have this price nor did I understand the value of increasing the thickness up from the other options. It was the right call and I would do it over again without hesitation.

The interior of the greenhouse would be exposed framing, allowing the owner to attach shelves, hang hardware or adjust anything without the headache of navigating sheeting, Durock or other materials. One thing I will tell anyone building a greenhouse is that you think you have it all dialed in, but things ALWAYS change when you start using the structure. You can add items to the building as needed, and the most simple solution is typically the best to start with.

Additionally I wanted to give the owner the option to have running water available inside. However, plumbing water can be a challenge for a few reasons. In Idaho our winters can get very cold so protecting pipes even inside the structure can be a challenge. Draining pipes is difficult and if you forget to drain and it freezes, you have a major issue to content with. My solution is this…. Trench in a 2in conduit and leave it empty. Snake a small flexible garden hose through it and attach it to the house spigot. Bring the male end up inside the greenhouse and attach it to a manifold that distributes the water as needed, where needed. Then when you're done you can disconnect the hose and it will drain enough to not burst if it freezes. The Manifold will also drain and alleviate the issues inside the greenhouse.

Next is power, I plumbed in conduit and power. I tied it to a sub-panel at the owners hot tub since there was capacity there to do so. This came up inside the GH and was protected by GFI.

The power drove the hi CFM fans, lights and gives the owner the ability to add devices as needed (i.e. monitoring, cameras, fans, sensors etc.).

Lastly was gas. This was so the owner could add a thermostat and heat the GH if they wanted to. They may get into tropicals or need to start waking up plants early for a show or event. They may just want to work in there and need a bit of heat to do so. This came by way of a gas heater. I mounted Durock on a panel allowing the unit to be safely installed and protect the structure from heat.

CONSTRUCTION

The construction of this project starts with laying out the footprint, then moves onto taking in the variables I discussed earlier, sun/shade, obstructions, visual weight, and the design. Once this was final, dig-line and approvals were completed.

I cleared the footing locations marked and triple-checked measurements etc.

One of the toughest parts of this job was the TRENCHING. Navigating the roots, data lines, sprinklers, hard-pan soil and dinosaur egg rocks…. NOT fun…..! I moved several sprinklers, tons of rocks and even with a heavy-duty trencher had to break up roots and hard-pan by hand or with a saw….. Crazy tough….

Once the trench was in, gas was prepared, the conduit for power was in and the water line was good to go, the inspection happened and we passed w/o issue.

The next thing was the footers and j-hooks for the framing. I had to move several sprinkler lines, cap off a few that were no longer needed and then work around the gnarly root system of the maple. After laying out the perimeter with stakes and string lines the piers could be measured and holes punched into the ground for the sono-tubes.

The piers were then poured and the j-hooks were set. Drying was 2 days and then the framing began.

I framed each wall and braced them to each other as the sections were stood vertical. This portion of the job was quick and painless. The roof was next.

The roof trusses were fairly straightforward. I made a jig to replicate each truss and speed up the framing process. Once that was done, I worked on the blocking and then sheathing.

Since this customer wanted this to have a similar look to the fence, the design incorporated 10/20 cold rolled steel around the base perimeter. This would provide the necessary structural rigidity to support the structure and prevent racking. The process of procuring, cutting and installing the steel was very labor-intensive, costly and time-consuming. I do like the way the pieces turned out. I would do this process again without hesitation.

Now I started working on the poly walls. Since I made the call to add the bracketing and connection joints this was pretty easy for most of the panels. I took measurements and placed panels and rails together making cuts simple, joints clean and install as simple as possible. The only pieces that were challenging were roof edges and where the walls joined the roofline. Since there were no overhangs on the south and north walls these joints needed to be very clean and precise.

After the poly was trimmed, the customer opted not to spray or seal the cedar on the greenhouse so that it would patina and match the fence over time. The cedar does need some protection in areas where water makes frequent contact or can soak into the end-grain of the wood causing swelling and making the wood deform. I also protected the end-grain with sealant. For an added touch I cut and welded 10/20 steel end-caps for each corner joint on the roof. This too will rust and match the base as well as the fence.

The remaining work was to finish off the electrical, trim out the door, install insulation, paint the insulation, and then in the corner of the greenhouse where the sink and gas heater were installed I needed to place Durock so that the heat wouldn’t be an issue and water was less likely to be a problem if water was left on etc.

OHHHH I also forgot about the drain for the sink, I used a sump basin. I dug a decent-sized hole and plumbed the water to that, filling the exteriorarea supporting the basin with gravel and making perforations so the water could seep back into the ground. SIMPLE. All of these items came together pretty smoothly, I then finished off the work with a load of gravel that matched the existing landscape, leveled everything off and I was finished.

WHEWWWHHH it was a PROJECT.

Thanks for reading and let me know if you have any questions!

THE CHALLENGE - A CUSTOM GREENHOUSE