Choosing a Greenhouse
If cost is not an issue, the growing space you require is likely to determine the size and style for your new greenhouse. Without space or budget constraints the options available are vast! However as the majority of us have a limited amount of space in our garden; it is this factor you should look at first.
Ideally the first thing to do is a quick survey of your garden by doing this first you’ll identify all of the options available for the best position for your new greenhouse. There are several important factors to bear in mind:
Shelter from the wind
If your garden is in an exposed position then consider the proximity of hedges or fences that will provide some shelter from the direction of the prevailing wind.
All greenhouses can be vulnerable to strong winds so it is important to consider the proximity of hedges or fences that will provide some shelter from the prevailing Wind. It is also a good idea not to position the greenhouse under any trees as storm damage to the tree can result in damage to the greenhouse from falling branches etc.
The greenhouse should ideally be positioned so that the longest side of the greenhouse will be fully exposed to the sun from the south. However this is more important with long narrow greenhouses as the most common sizes of greenhouse, such as the 6′ by 8′ are almost square so an east to west orientation makes hardly any difference
A level site is important for your greenhouse to give stability and strength. The most common method of foundation is to lay flag stones or slabs with an overlap of around 6 inches outside the dimensions of the greenhouse base. Fixing your greenhouse directly into the soil is not nearly as secure or as strong as bolting the base of the frame to a hard surface. Most greenhouses are supplied with an aluminium base or concrete base kerbs on which to mount the greenhouse frame.
Water and Electricity
The chances are you will want water and electricity in your greenhouse for things like heaters, propagators and automatic watering systems so it is important to think about this when choosing the site for your greenhouse.
What size of greenhouse do I need?
If space is not an issue it largely depends on how much growing you plan to do and how much storage space you want inside the greenhouse. We‘d advise you to choose the largest greenhouse you can accommodate in your garden within your budget as the most common complaint about greenhouses is that they are too small!. For example if you were thinking of buying a 6′ by 6′ but have the space and budget, we’d recommend going for a 6′by 8′.
Measure the site
The most important measurement is the width – traditional greenhouse styles offer a choice of nominal widths, in 2′ increments e.g. 4′, 6′, 8’10′, 12′ etc. The length of the greenhouse can then be specified to fit into your site.
Traditionally, greenhouses always used to sit on a little brick plinth. Now however, most greenhouses are supplied with a metal base. This means that you can fix the greenhouse straight onto either a concrete footing or a base made up of concrete slabs. Alton Greenhouses come with concrete base kerbs that do the same job.
Do I need a base?
You do need a metal base on most greenhouses; the only exception to this is the Robinsons range of greenhouses. The greenhouse would traditionally sit onto a small brick wall so that the bottom sill of the greenhouse frame would overlap the edge of the brick. Having a metal base removes the need to build a small brick wall because the greenhouse can overlap the metal base. Another benefit of using a metal base is that it gives you an extra few inches of height inside your greenhouse.
Greenhouses can now be supplied in a variety of colours including Black, White and Green.
Powder coating provides a vastly superior finish when applied to metals and is guaranteed for 10 years and usually has a life of 15-25 years.
Standard horticultural glass
This is the standard window glass and most commonly the panes measure 2′by 2′ and these overlap by about half an inch where they join. Horticultural glass breaks easily into large and dangerous shards and is difficult to clean making it unsuitable if there are young children or pets running round the garden.
Toughened Safety Glass
Toughened safety glass is far stronger than horticultural glass leading to fewer breakages. If it does break it doesn’t crack, it shatters in to small glass crystals making it safer as the glass will disintegrate into hundreds of small pieces that will not usually cause serious injury. It is also usually supplied in larger panes meaning less overlaps and so less cleaning is needed!
On some greenhouses, twin wall polycarbonate is available instead of glass. It does have certain advantages over glass, it doesn’t break like glass so it’s considered safer for children and has better insulation properties.
However, we would advise you not to specify polycarbonate glazing for the following reasons: –
Over time, the cavity between the twin walls can fill with condensation that can turn green with algae making it unsightly and it is impossible to clean.
It is Opaque
It is very lightweight, and flexible and therefore very vulnerable to wind damage
It is Expensive