Roll-Up Curtain Direction and Vertical Guide Pipe Installation
When a rollup curtain opens, the horizontal roll bar can be set to turn in one of two directions: rolling toward the outside of the greenhouse or rolling toward the inside. The vertical guide pipe can also either hang freely or be fixed into the ground. Installers and distributors differ on both points. After more than 20 years of installing and supporting rollup curtain systems, we recommend that the roll bar roll toward the outside, away from the house, and that the vertical guide pipe hang freely.
Roll Direction
When the roll bar rolls toward the inside, it can catch plants growing along the sidewall and pull them into the roll, damaging both the crop and the structure. Rolling toward the outside keeps the crop out of the curtain’s path. Weeds and other vegetation along the outside of the house can still be caught, so outside growth should be kept trimmed as part of regular maintenance. This is far easier to manage than protecting plants on the inside of the house.
Rolling toward the outside also extends the life of the poly. Most greenhouses have sidewall posts on the inside of the house, and when the bar rolls inward, the roll presses against those posts more as it grows larger. Over time, the tension and rubbing will wear through the poly. The outside of the house typically has only straps or wind rope, which do not cause the same damage. If your greenhouse has posts on the outside, contact us to discuss the best setup.
When a Roll-Lock is used, the bar must roll toward the outside. The poly needs to roll down around the Roll-Lock bar and then come back up, which is only possible in this direction.
The most common reason given for rolling inward is so rain runs off the edge of the poly instead of collecting in the roll. The concern is that when the bar rolls toward the outside, water will get caught and puddle behind the roll bar. In our experience, this is not the case. When the curtain is installed properly and there are no wrinkles in the poly, it rolls up evenly and water does not collect in the roll. Taking the time to remove wrinkles before attaching the poly to the roll bar is the most important step in getting an even roll.
Vertical Guide Pipe
The vertical guide pipe should hang freely from a guide pipe extender at the top rather than being fixed into the ground. The extender can be made with pipe from a hardware store. A hanging guide pipe gives the motor room to shift slightly left and right as it travels, which helps prevent the rollers from binding. A fixed guide pipe does not allow for this movement.
Other Installation Methods
Growers may choose to install their system differently, and some will receive other instructions from their distributor. The recommendations in this article reflect what we have found to work best over time, and our troubleshooting is based on this setup.