A Guide to Building a Greenhouse on a Stem Wall: What You Need to Know

A sturdy greenhouse foundation is critically important to ensure its safety and effectiveness. Sometimes, strong winds, heavy rainfall, and other environmental conditions can damage a greenhouse, especially if it doesn’t have a strong foundation.

A greenhouse with a structurally integral base will last longer and help you make the most of its benefits. This is where a stem wall comes into play. Many greenhouse gardeners, particularly beginners, don’t understand the importance of stem walls.

In simple words, stem walls are an outer structural wall that holds a greenhouse above the ground to protect it from surface-led moisture.

We have discussed everything about building a greenhouse with a stem wall in this blog. So let’s delve deeper right away!

Stem Wall—A Brief Definition

Stem walls are like a building wall that keeps a greenhouse anchored to the ground. It increases the strength of the greenhouse foundation that holds the entire structure in place. So do all greenhouses require a stem wall foundation? Yes, they do, except portable and cold frame greenhouses that are mobile and flexible.

So when should you consider adding a stem wall to your greenhouse foundation? A stem wall becomes necessary when building a wooden or concrete greenhouse foundation. It creates a pillar-y support for the structure. And the best part is, with stem walls, you can install a greenhouse on any surface.

Stem Walls are More Effective than Foundation Walls

When building a greenhouse foundation, stem walls can be created using building blocks at low-level footers. It’s more stable and well-elevated than foundation walls. While some may argue that creating stem walls is a laborious process, they offer versatility and strength. Whether you live in a flood-prone region or a hilly area, stem walls can help you install a greenhouse without worrying about the ground conditions.

A greenhouse built on a stem wall

Expert Tips for Building Stem Walls for Greenhouses

Here are some expert tips to increase the effectiveness of stem walls for your greenhouse:

  • While most greenhouse manufacturer manuals recommend installers to use concrete slabs, you can opt for stem wall for improved sturdiness
  • Leveling a concrete slab foundation can be a challenge. Instead, go for a stem wall for an easy and smooth process
  • Locate a spot where your greenhouse can receive at least six hours of sunlight
  • Your stem wall should not cause a hurdle in the irrigation and drainage process
  • Marking the footing levelis essential before you start building a stem wall foundation
  • Take help from ACI-318 design equations to determine the adequate level and thickness of stem walls for your greenhouse

What to Consider When Building a Greenhouse on a Stem Wall

Stem walls can significantly reduce the risk of erosion, moisture traps, and moving water damage for greenhouses. Some of the main factors to consider when building one should be lateral support, the height of the greenhouse, grade elevation level, and type of ground conditions.

The embedment height for stem walls is recommended to be at least eight inches above design flood elevation. Since stem walls aren’t made of concrete or any other kind of slabs, it’s important to measure correct height and width along with the code compliance.

Since it lifts the greenhouse, a drop-down door kit will be needed in order to let a gardener inside the greenhouse without using a step. 

How Mulberry Greenhouses Can Help

Mulberry Greenhouses is a leading greenhouse kits and greenhouse accessories distributor in the US. From Solexx and Riga to Monticello and Exaco, you can find all brands on our website.

You can also find the best quality greenhouse watering systems, greenhouse solar power system, flooring, and tie-down kits at Mulberry Greenhouses. We’re currently offering up to 70% off this winter season. So shop now or contact us today!

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