Roll Top Greenhouse Bench

Tool Concept


In the winter and early spring, seedlings in the greenhouse need extra protection from frost. Bench heating systems can provide the necessary bottom heat but without covering the bench, much of the heat is lost. Farmers typically cover their benches with agricultural fabric, plastic, or both but putting this plastic on and taking it off daily is cumbersome and takes time. This roll top system enables one person to quickly cover or uncover the heated bench.
Documentation Wiki: 
Roll Up Bench Cover Problem Statement/functional need

We needed a quick and easy way to cover and uncover our heated bench in our propagation house. Previously, we had manually covered and uncovered a PVC frame with a sheet of plastic. This was cumbersome, time consuming, and took two people. This system can be operated by one person in a matter of minutes. Because the system is easier to manage, we're more likely to control the temperature of our delicate seedlings better.

Functional Description/approach

The roll-top system consists of two roll up sides. One which goes horizontally over the table, then all the way to the ground. The other covers the vertical side, all the way to the ground. We store trays underneath our seeding table so we wanted to have easy access to this space but we also wanted to have the option to close both sides all the way to the ground for better heating efficiency, especially for cold nights. So, we installed cleats which can catch the roll-up pipe at table height on both sides of the table. Essentially, each side has three positions: fully open, open to table top height, and closed to ground level.

Each side consists of 1 5/8" chain link fence top rail (this material comes swaged so that the end of one piece fits inside of the next). The pieces of top rail are held together by a single 1" tek (self-tapping sheet metal) screw. Plastic is held onto the top rail by PVC washers (we used 1 1/2" PVC which we cut lengthwise on the table saw into thirds, then to 8" lengths on the chop saw). The washers are tek screwed to the pipe. We found that one screw per washer was sufficient. Washers are spaced every 6' down the top rail.

The frame consists of wood uprights with two 1x4 boards along the top. The plastic is sandwiched between the 1x4s and is one continuous piece. 1/2" conduit forms the bows. We bent the conduit on a home-made pipe bender (see photos).

How to use the tool

Use this tool to control the temperature of your greenhouse bench. This could be useful for either heated or unheated benches for seed starting, sprout and microgreen production, etc. On warm, sunny days, roll up the sides to allow the space to vent.

Bill of materials and Sourcing

We built this mainly with scrap material we had on the farm.

Construction/how to build
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