Using Simple Math to Build Your Greenhouse Foundation
Building a solid foundation for your DIY greenhouse isn’t hard as long as you pay attention to several important dimensions. Your finished foundation needs to be square and level in its construction. Since most greenhouses have square corners, you must be sure that whatever foundation you build will follow these corners perfectly to avoid creating gaps where water and small animals can enter the finished DIY greenhouse. The good news is that a bit of simple math can help you keep these corners in order and make building the perfect foundation a snap.
Check Your Greenhouse Plans for Specific Dimensions
Most greenhouse plans will list the outside dimensions of the finished greenhouse. This measurement is critical in the design of your foundation and helps you understand how long each side needs to be. For proper support and weatherproofing you want the foundation to be about an inch wider than these outside dimensions to provide a good seal. This allows you to create a tight mounting point between the sill plate and the base of the DIY greenhouse for support. By anchoring the DIY Greenhouse to the foundation securely you can prevent leaks in harsh weather and tightly anchor the structure to avoid damage from high winds.
Make Sure Your Foundation Is Square
One of the hardest things to do with any foundation is keeping the structure square. Because the sides can be somewhat longer, you’ll need to have an easy way to check that everything is aligned before securing your lumber or pouring the concrete. One of the simplest ways of doing this is by using a little math. Since the corners on most DIY greenhouses are always 90 degrees you can simply measure the distance between the corners diagonally and compare the two measurements to make sure they are the same. You can also calculate what this distance should be by using the formula A2 + B2 = C2. You simply plug in the length of the two sides as A and B to calculate how long the measurement along the diagonal should be. This will give you the exact length required to make sure the foundation is square and will match up perfectly with the finished DIY greenhouse.
Know Your Setbacks
Another important consideration is the location of your greenhouse. Many areas have building codes that specify how far a structure like a DIY greenhouse has to be from your property line. You’ll need to know this and incorporate it into your greenhouse plans to avoid problems later on. If you have a smaller yard, you’ll want to locate your greenhouse as close to this setback as possible to allow you to build a larger building. Be sure to carefully measure this distance before setting up your foundation flags so you know you have the required setbacks.
The final critical measurement has to do with the height of the foundation. With any building like a greenhouse you need to make sure that the structure is raised high enough to avoid being flooded with rainwater. This requires a careful inspection of the surrounding area that can help you determine the proper height for the walls of your foundation. You’ll want these walls to be a minimum of 6 inches above the highest area near the greenhouse to ensure that any water that collects near the foundation runs away from the building. This will provide adequate drainage for the building and help your foundation last longer.
All of this math may be provided with your greenhouse plans. These will usually detail the specific measurements you need for the foundation, but it’s always good to understand how to measure them on your own. This way you can use these formulas to double-check the measurements supplied with the greenhouse plans and possibly avoid costly errors with the construction.