Installing Wire Insert on Multiple Layers of Plastic

In response to a few questions about increased difficulty of installing the wire insert on 3 layers of 7.2 mil plastic. I have done my experiment with zero added degree of difficulty.

I don’t want to leave it just like that. I would like to add a few points.

First of all, the temperature was about 18C when I did this. It will progressively get more difficult because the plastic is less pliable as the temperature gets colder.

I should follow this up with the same experiment when the temperature is below freezing.

For my experiment I put extra screws into the channel simply to increase the chances of interference between wire insert and screws.

I had one instance where it was a little more tricky and had to push a little harder.

I could see that there could be a possibility where you might need to take out the wire insert and start 1 centimeter over.

There are a few things which I wish to point out on logistics and technique. There is a critical thing to remember for the helper who is pulling on the loose plastic.

He/she must be pulling at least 30 cm ahead of where the wire is going into the channel to allow the necessary slack to get the wire into the channel.

The same applies for the person inside the structure who is pulling on the end wall cover.

Inserting the wire insert is very much a wrist action and proper technique is probably even more important when doing 3 layers of 7.2 mil

Your thumb should be on the next equal bump (either up or down) so that you can apply some twisting action to the insert.

Never simply slide the insert up and down as this can abraid the cover.

I hope this helps

Norm

The Benefits & Drawbacks of Roll-up Sides

The main attraction of roll-up sides, as a method of ventilation, is that it is economical. There is not a significant investment and can be added to virtually any structure. Regardless of structure length, nowhere is very far from open air.

It is only by properly understanding the limitations and drawbacks that one can maximize the benefit. Just because something is inexpensive does not mean that it won’t end up being costly if it does not fulfil its purpose.

Roll-up sides should always be done in pairs (both sides). Even if you have a really high percentage of prevailing wind from one direction, there will be times when you need to ventilate into the prevailing wind.

Any time you have wind going in without opportunity of escaping,
there can be damage to the building.

The average vertical opening of roll-up sides is usually about 4’. If your greenhouse is in an extremely exposed area without any protection or wind breaks, quite often 2’ of vertical opening will be sufficient.

On the contrary, if the building is extremely sheltered, 6’ of vertical opening will be required.

One thing to remember on the height of opening is that if you have a low profile structure with a high opening, a sizeable area could get wet inside when it rains.

Regardless of the size of opening, if there is not a breeze, you will not have air movement.

It is based on this potential problem, that we recommend having end wall openings as high as possible. These openings will trigger a “chimney effect” air movement that will get rid of hot air that is trapped in the greenhouse. These openings will double as your first stage of ventilation since they would be opened when it is too cold outside to start rolling up the sides.

A drawback of roll-up sides is the amount of exposure they create for airborne weed seeds and pests. It is important to remember that when you use shade cloth to minimize this drawback, you are also significantly restricting incoming air.

The biggest drawback of roll-up sides is that there is no practical way to automate them. In other words, you have to be there to open and close them. This can be challenging on the cool, sunny days that have sporadic cloud cover. The sun goes behind a cloud and the temperature plummets and then soars when the sun reappears.

The best way to minimize this challenge is to add a small exhaust fan to the set up. This way you will have something to handle the borderline situations and then open the roll up sides once there is a more predictable need.

In the next article we will explore forced ventilation in greater detail. We also have many resources on our website, as well as videos if you want to explore the topic of roll-up sides further.

roll-up side videos

roll up side considerations

roll-up side Q&A

February Features! *Winter and Your Structures*

We have a number of resources on our website to help you with taking care of our structure over winter. We have compiled a list of “Greatest Hits” below, that you can review at your leisure and please don’t hesitate to contact us with any questions if you are unsure or can’t find what you’re looking for. We are always happy to help.

The best place to start is the Winter Care Pages in our instruction manual.

We also have: Winter FAQs

Video: Norm explains the situations where you would need to remove snow from a Greenhouse or Storage Building and how to do it safely

Winter Care & Maintenance
Important notes for various situations
Our structures are designed in a gothic shape with a slippery cover to be lightweight and snow resistant. This encourages the snow to slide off quickly. This is not an industrial high snow load building….

Weather Cautions
These buildings are not industrial grade shelters and, as such, some caution must be exercised under some winter storm conditions….

Winter Storm & Your Structures
Many areas have been hit with freezing rain today and even though it has generally not been enough to warrant concern for the structures, it is a good time to recap some common things when dealing with ice on buildings….

Retightening a Loose Structure Cover
Re-tightening a cover does not have to be done in one day. Taking a short cut will leave you with more wrinkles. Areas with wrinkles will flutter more and cause stress points.
This will also cause the cover to deteriorate quicker……

Temporary Fix for a Loose Cover
There are a number of instances where a cover will need to be installed in less than ideal conditions. This can be either be on a windy day or in the cold (-10C or worse) and the job simply can not wait.

Season Extension: Hanley Caterpillar Tunnels
The real lure of these buildings is their low cost and simplicity to move. Generally the area is prepared in advance and then the tunnel is moved over the area when the planting is to be done…..

Happy Valentine’s Day and Family Day! We hope you and your family are staying warm, and getting excited for the upcoming spring and growing season! We look forward to working with you on your projects in 2021!

Season Extension: Moving Your Structure

A significant part of season extension involves moving an intact structure.

This basically allows you to get two (or possibly three) plots of production from one investment.

The idea is to start a relatively cold tolerant crop very early in the season (the timing will be different in different locations).

  1. Once the crop is firmly established in location A, (and it has warmed up) you will move the structure to location B and start another crop.
  2. You will harvest the crop in location A and then after working the soil, plant another crop in location A which is intended for fall harvesting.
  3. After location B is harvested and before frost you will move the structure back to A.
  4. Instead of doing twice in location A you could also choose location C.

A structure can be equipped with wheels which will run over the soil. There is quite a bit of flexibility where you go and the terrain you navigate.

The structure can be equipped with rollers on a track. This will determine where you go and this is usually intended for moving a bigger structure with fewer people.

The most common method of moving is sliding the structure on the soil. The base rail can be wood or steel.

It is critically import to understand the logistics of moving on a structure before you start. It is not hard to move a structure but it is also not hard to do damage.

Having a plan for proper anchoring is very important for a moveable structure. Your structure is at a vulnerable state when you release the anchors. Once you start, the job must be completed quickly. You have to be aware that the anchors may not come out or go back in easily so you may need to give yourself some extra time.

One other area of consideration on a moveable structure is the ends. There must be some sort of a flap or vent along the bottom so that when a structure is being moved, the ends will not uproot plant material. Generally speaking to have this ability in the ends takes away from the structural integrity, so some extra anchoring may be required.

You can see more information and photos on our movable information page. Please don’t hesitate to call us with ANY questions you may have. This can be a very useful addition to your structure, but must be understood correctly.

Stay tuned for part two and three of our season extension series later this week!

Season Extension: Ventilating & Heating

To make your greenhouse more of a year round functioning entity, there are two main areas in which you have to make the structure more efficient-Heating and Ventilation.

1. Heating is your biggest expense for the winter so retaining heat is a priority.

The easiest way to retain heat in your greenhouse is to install a double poly cover with air in between. A small squirrel cage blower attached to the inside layer of plastic aids in maintaining air between layers.

The more dead air space between these layers you can create, the closer you will be to achieving a 30% reduction in heat loss. Holes will result in air movement and therefore less efficiency. 3″-5″ consistent space is ideal. It is a given that you would have less then that around the edges and over the ridge.

Double plastic will have a considerably longer life span. It is important to realize that as plastic gets older, the light transmission will be reduced which will reduce production.

Infrared plastic (IR poly) does further reduce heat loss and increase light diffusion so it can also be a consideration when looking for ways to reduce heating costs.

2. Ventilation is also one of your biggest considerations for the warmer times of the year. Ventilation can be done through forced or mechanical methods or passive through vents or roll up sides.

Vents are extremely effective since they can be placed higher up where the heat needs to be expelled. Mechanical ventilation is more costly both up front and to operate but it is easier to control since it is attached to a thermostat. For mechanical ventilation to be effective, it needs to be sized and located properly.

Roll up sides are less costly and simpler to install but are restricted by the fact that you have to be there to open and to close.

Climate control is especially challenging in the spring and the fall since most days you will have the need for both ventilating and heating.

One area that you need to be especially aware of is stagnant air. Without proper air movement, circulation and exchanging, stagnant air can cause many different types of diseases. It is important to understand what your plants require

Stay tuned for the third and final installment of our series about Season Extension and Your Greenhouse coming soon!

Modified Hanley Tunnel

One of our most popular structures is the hanley tunnel because it is the cheapest way of covering an area for season extension.

As a way of addressing some of the challenges and limiting factors with the tunnels, we have come up with a modified hanley.

The two areas where it significantly improves on the regular tunnel are the side clearance and the peak for snow shedding. Instead of using 24’ of steel to make 17’ wide and 7’6” high, we are using 26’ of material to make 16’ wide and 9’ high. It still uses 28’ wide plastic with extra at the ends to make the same kind of “tails”.

Sliding the plastic up on the sides is still the way that the tunnel is ventilated and you will still have the same challenges as far as creating access.

The re-bar anchors, base plates, clasps and rope are the same on the modified hanley as they are for the regular tunnel. We supply 5’ more of extra plastic for the tails since the building is taller.

The peak on the end hoops are very hard on the plastic, so we have designed a more rounded hoop at each end. It is strongly recommended to have 3 guides ropes at each end to brace back to the anchoring posts of the plastic.

Any structure with ends is not considered a Hanley Tunnel. We are more than willing to discuss the differences and benefits/drawbacks between tunnels and cold frames should you wish to know more.

The main thing which is critical to understand before going with a modified hanley is the extra wind load which the structure will be subjected to. Going from 7’6” to 9’ high, results in a 40% increase in the wind load. This issue is what makes the correct tightness of the ropes an even more critical consideration.

It is also the reason why we strongly urge customers who
do not have any tunnel experience to start with a regular tunnel.