Magnum 128 12x8 double-door model
A superb greenhouse offering over 9m2 of growing space. A strong aluminium frame, using cast iron joints, ensures this spacious and stylish structure is completely safe. It is fully inclusive of integral gutters, smooth action sliding double doors and 4 roof vents. The Halls Magnum Double Door Greenhouse range is a stylish addition to any garden.
Length: 12 '7"
Width: 8' 5"
Ridge Height: 8' 0"
Eaves Height: 4' 6"
Roof Vents: 4
Growing Area 100 sq. ft.
Heights do not include base which adds 5"
1 meter = 3.2808399 feet and 1 mm = 0.0393700787 inch
|Growing area ||9.3 square metres |
|Door opening width ||1200 mm |
|No. of vents ||4 |
|Internal height to ridge ||2.390 metres |
|Internal height to eaves ||1.360 metres |
|External width ||2.570 metres |
|External length ||3.830 metres |
|Addition of base to height ||128 mm |
Freight: YOU MUST SELECT THE LTL SHIPPING METHOD WHEN CHECKING OUT. All orders will ship from Grants Pass, Oregon USA. Kits and bases will be shipped via the LTL common carrier Oak Harbor Freight -- as such we will be able to ship only within the continental United States, Canada, and Mexico. Shipping at checkout may not be accurate -- actual shipping charges will be collected separately if there is a difference in price and over charges will be refunded. Most accessories can be shipped via UPS.
All About Halls Greenhouses
English-made quality aluminum frame carries a manufacturer’s 15-year warranty, and will not corrode, rot, or rust.
Sliding door won’t slam in the wind; doubles as an adjustable vent in warm weather.
Simple cushioned snap-in glazing system holds glazing panels securely in place, and allows for easy removal if needed.
Choice of glazing options:
Extra-thick eighth-inch double-strength glass (NOT AVAILABLE ONLINE) provides a traditional English look (tempered glass available as an upgrade).
High-impact resistant 4mm twin wall polycarbonate panels are available on most models for increased safety and insulation value. Panels are UV stabilized and carry a limited 10-year warranty.
Complete weather-stripping minimizes heat loss.
Large roof vents with adjustable openers allow for easy cooling. Automatic openers are available (no electricity or batteries needed).
Choosing a Site for your Greenhouse
Choose a level, clean site in a low-traffic area, with easy access to power and water. Your greenhouse should receive the maximum amount of winter sunlight available. Be sure to consider the following:
The change in angle of the sun between summer and winter
Shadows cast by existing structures and/or trees
Growing evergreen trees or shrubs: Will they shade the greenhouse in the future?
If possible, align your greenhouse with one long side facing south or southwest, for two reasons:
The angle of the roof is engineered for catching the maximum amount of the sun’s rays in the winter with the least amount of loss by reflection (like a solar panel)
If you end up using shade cloth during warm days in spring and summer, you will only need to shade one side, instead of both sides.
Tips on Installation
Your greenhouse must be installed on a firm, strong base. The optional steel base is
perfect, and includes anchor pegs which should be set in concrete (very important in
windy areas). Or you may use a 4x6 (on edge) pressure-treated lumber base, or even a
brick or poured concrete footing. Make sure the base is both level and square before
continuing with the frame assembly to ensure the glazing panels will fit properly.
Small gravel or stepping stones are recommended for flooring material.
If your kit comes with only one or two roof vents, installing them on the north side will
prevent interference with the shade cloth, which will be installed on the south side.
Installation of most models can usually be accomplished by 2 people in a week-end.
Basic tool list for installation: level, 10mm nut driver or 3/8” ratchet with 10mm socket, 10mm or adjustable wrench, pocketknife, pliers, measuring tape, screwdrivers, gloves, stepladder.
Cooling Your Greenhouse
Even on a cool day, a greenhouse in full sun that is closed up tight can get quite hot Roof vents are used to allow hot air to escape, to be replaced by cooler air from the outside. But during the early part of the season, you want to trap as much of the warm air inside to last into the night, to save on heating costs.
This fine balance can best be achieved by the use of optional automatic openers for the vents. These openers can be adjusted to begin operating at different temperatures, depending on the plants’ needs. As the temperature inside the greenhouse increases, the vent automatically begins to open. If the temperature continues to rise, it opens more. As it cools off later in the day, the vent automatically closes in the same manner. These openers require no electricity or batteries to operate.
In the heat of summer, the vents will often remain open both day and night Additional ventilation can be achieved by adding one or more louver windows, usually installed opposite the door or on one side, down low to allow for the entry of cool air. If needed, one or more glazing panels can be removed for the summer. Remember to use the door as a vent also when needed. (In the winter, the automatic openers can be disconnected.)
Shadecloth will be needed to prevent damage to tender plants during warm weather. Usually 50% shade is adequate, though 70% may be preferred for sensitive plants.
Heating Your Greenhouse
If you intend to start bedding plants early or overwinter tender plants, supplemental heat will be needed. For the smaller greenhouses, a fan-forced electric heater with an output of approx. 1750 watts (or about 5000 BTU) should be adequate. Be sure it has a grounded (3-prong) plug. The larger models will need a correspondingly larger heater—15,000-20,000 BTU. Electric heaters this size are expensive to run—you will save on heating costs by using a propane or natural gas heater instead. (If you live in an unusually cold area, you may need a correspondingly larger heater.) Be sure you get a heater with a built-in thermostat, or purchase a separate thermostat into which you can plug the heater cord. Remember to have a GFI (Ground-Fault Interrupter) circuit installed on the outlet in the greenhouse by a qualified electrician. A suitable heater can be obtained from many hardware/electrical supply stores, or a natural gas company.
If you choose to purchase a glass model (NOT SOLD ONLINE): Double-strength glass is quite strong and impact- resistant A few cautions will prevent most mishaps:
Always wear gloves when handling glass.
Always store glass on edge. Never lay it flat
When choosing a site for your greenhouse, beware of falling limbs, cones, etc.
Stay away from high-traffic areas if possible.
In many areas of the United States, building permits are not required for ‘portable’ structures, including greenhouses and sheds, under 120 sq. ft (All Hall’s greenhouses except the 14x8 models are under this size.) Planning permits will normally be required, however. Building permits required for lean-to models, and are the homeowner’s responsibility to obtain. Please check with your local building or planning department for more information.
— LTL Shipping Required.
— Ships via LTL from Grants Pass, Oregon USA.
For more information, please visit the manufacturer Halls' website.