What is and isn’t “proper ventilation”?

Proper ventilation, in a nutshell, equals adequate air changes and movement while maintaining adequate light levels and humidity in a given area. Proper ventilation is about proper balance.

The challenging part of achieving this balance is that there is such a wide range of requirements for different plants. It is important to identify what is ideal for each variety that you are growing. It will not be feasible to have a perfect climate for each variety of plant, but you really should avoid grouping together plants with a wide difference in requirements. That would simply ensure that you are not doing very little properly.

Putting shade cloth over a greenhouse may lower the temperature to an acceptable level for your plants but that does not equal good ventilation. You may be depriving the plants of their critical light requirement plus you are not doing anything to enhance air movement.

Turning on an exhaust fan may create the required amount of air changes or movement, but with a temperature far below the plant optimum, your plants still will not achieve their potential. Fans also draw air in a straight line from intake to exhaust. This does not address “stagnant corners”.

Many times, light equals heat. They go up together and go down together. It is important to understand how and why they are controlled differently and where the overlap on that control is.

Generally speaking, proper air changes equals one air change per minute. Some plants require more and some can get by with less. For this, you will need to know what the air volume is for your building. It is a little trickier to calculate this on a gothic or quonset shaped structure. Using the length x width x 80% of peak height will give you a close enough number in either cubic feet or cubic metres.

With the next 4 posts we hope to create a more thorough understanding of how to achieve a good environment for your plants. This information will be helpful as to research options so that you can balance costs with benefits and return. Especially in the area of ventilation, many times expenses associated with proper ventilation will be offset by exponentially higher returns.

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 movable 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 movable 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.

Season Extension: Hanley Caterpillar Tunnels

The first area to discuss regarding season extension are those structures that are simple enough to disassemble and relocate to another spot-primarily referring to 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.

Since the original design specified 6′ hoop spacing, the intent was always to remove the cover before risk of heavier snow fall. More often now, growers are going to 5′ spacing (and sometimes 4′) to allow the covers to remain on longer or even permanently.

By having a smaller hoop spacing, it allows the cover to stay on permanently, which allows for a much earlier start in the spring.

The key to the concept of the Hanley working is in the rope.

  • The back and forth pattern of the rope resembles the way a person would lace up a boot.
  • Typically there is a spring loaded clip at the base where the rope passes through.
  • Once the rope is fully installed, it is important to tighten it through three passes from end to end.
  • If the rope is not tight enough, the wind will create wiggle and movement sideways.
  • When the plastic is tight enough, it also allows the grower to slide the plastic up the hoop to allow ventilation.

Generally the plastic is about 25′ longer then the tunnel.
This allows the installer to bunch up (pig tail style) the extra poly at both ends between a pair of posts.
It is important to get the plastic as tight as possible lengthwise first.
There must also be a rope from the top of the last hoop to the tie off post.

There are a couple of challenges to consider with the hanley tunnels.

  1. One of these challenges is to create a proper entrance. Typically entrance is achieved by slightly lifting the plastic and ducking underneath.
  2. The other are of challenge is the low shoulder height of the structure. This restricts the use to a couple rows of taller items in the middle and a couple rows of shorter plants along the side. The width of the tunnel does lend itself to three regular size beds.

Once you have learned about the nuances of the hanley tunnels, and asked any questions that come up, you will be better prepared to have these efficient season extenders work for you and your application.

Feel free to look at our Hanley Application page for more information and photos, and give us a call with anything else you require.

We are pleased to have many happy customers these structures are working for, and look forward to you being next!

Check out our book if you want to know more “So You Want to Buy a Greenhouse…Your Guide to Planning a Greenhouse Purchase”

Why the Instruction Manual and Pick List are Important Partners in Your Structure Construction

click to watch video:

Every customer that gets a structure order from us will get one or more boxes of hardware. In these boxes are some important items that you must review before you get into the excitement of the actual building.

One of the boxes will be clearly marked that it contains the instructions. The instruction manual is a generic guide to building most of our buildings. The pick list you receive is specific to your building.

By using these together, you will make sure that your materials are properly accounted for and used in the proper sequence and manner.

This box will also have your name, a tag of coloured duct tape, and the number of boxes pertaining to that order. If there are 2 boxes, one will be marked as 1/2 and the other as 2/2.

The coloured tag will also be present on the bundles of your bigger hardware (hoops, purlins, etc). This is our way of colour coding parts of the order for our driver’s benefit to make sure you get a complete order.

The instructions consist of an installation manual and a pick list. You will get 2 pick lists. A “blank” one is inside the installation manual. The other one is marked and included in the pouch with your copy of the invoice.

The pick list must be used in combination with the installation manual. The pick list verifies the quantities and names of the different items you have received.

We would like to take this opportunity to remind you that you have 30 days to report any shortages. If you know in advance that you will not be putting the building up for an extended period, please call us to let us know and we can provide that leeway.

If there are terms on the list that you are not familiar with, please reference the glossary near the front of the manual. Many of the items on the pick list will have an associated part behind them. i.e. what bolt goes with what bracket.

There will likely be some parts of the manual that do not apply to your order. It is important to go through the whole manual to familiarize yourself with the background information we have provided to ensure you have a long structure life since it has been properly installed.

We are here to help you with the process. We are better able and more willing to help those customers who have clearly taken the time to review the manual vs ones who have not. We urge you to call to clarify things if there is a question. Many customers will take a picture of the question item and then email it. This generally speeds up the process.

As mentioned, the second picklist is in the pouch with the invoice. The markings on this are the double and triple checks that we have done to make sure we have included everything you need.

We appreciate your business and look forward to seeing pictures of your finished projects. We do offer a referral thank you program for those who have the opportunity to share about our products. Call or email the office if you’d like to know more about it.

How to Manage Structures in Extremely Windy Locations

Click to watch the video

How to Manage Structures in Extremely Windy Locations

One of the things which frequently comes up in the conversation with new customers is that they are in a very windy location. This is important to take into consideration when making suggestions for a building.

Occasionally we are faced with an intensely windy location. The question becomes, “Can I build a greenhouse in such a spot?” The short answer is “yes”. There are five potential suggestions which we make to improve the building so it is better able to withstand regularly brutal winds.

-Go with a lower profile shape since it catches less wind. Normally we recommend high profile since it sheds snow better but in super windy locations, snow is not an issue.

-Go with narrower hoop spacing. Going from 4’ to 3’ spacing increases the strength by 33%. Sometimes it is even worth going to 2’ spacing.

-Put in more anchors. There simply is no such thing as too many anchors! In super windy locations it is worth doubling up on the anchors. It is also important to double up on the fastener between the base beam and the anchor.

-Install cross ties. Cross ties tie the left and right sides of the building together. This means that when there is added pressure on one side, the other side is assisting by holding things back.

-Go with a double plastic cover with air between. It is amazing how the cushion of air acts like a shock absorber and stiffens the building.

Depending on the severity of your situation, adding a few of these to your building may help achieve the peace of mind you are looking for. We have had situations where a customer has added all five suggestions and been extremely grateful for the rigidity which has been gained.

As much as you, we want this building to serve your needs for many years with peace of mind.

Reporting and Discussing Structure damage

One thing that greenhouse operators don’t want to discuss is damage to their structure. With the increasingly regular occurrence of severe weather, it is something you need to be aware of to ensure a long structure life and service.

Being proactive is the best defense against the changes in our environment, controlling the variables we can.

At Multi Shelter Solutions we make every effort to make a superior and rugged product. We also inform our customers of everything required for the sturdy construction of these buildings.

Despite this, we strongly suggest a careful inspection after each major weather event, again, being proactive.

There is a level of satisfaction that comes after a structure comes through each storm. This is important, but if the structure has been severely stressed, this needs to be identified.

It will take less of a storm to do twice as much damage the next time.

A major warning sign would be things just not lining up the way that they used to. By sending us pictures, our experience will guide you to the areas that could be potentially damaged. To us, there may be flags which warrant investigation, that an untrained eye may not notice as an issue.

In worst case scenarios when there has been a structure failure, it is important to get us the pictures as soon as possible. It is important that details of circumstances are fresh in your mind.

When we ask questions, we are not trying to point any blame; we are simply trying to ensure, or at least significantly minimize, the chance of a repeat problem, when you do the rebuild.

We don’t sell you a structure, we help you buy one, and want to see your continued future success. Thank you for trusting MSS with your structure purchase and allowing us to share tips to increase your success and profitability