As you would expect, a greenhouse will only last as long as its frame. It is an obvious statement maybe, but nonetheless crucial to choosing a greenhouse. Selecting a frame is one of the most important aspects to consider when buying a greenhouse. The frame determines the stability of the greenhouse in all types of weather conditions and it is, in fact, the basic skeleton of the greenhouse.
Wooden greenhouses, typically cedar greenhouses are the traditional greenhouses. They were built and used long before aluminium and plastic greenhouses came into vogue. A wooden greenhouse blends very naturally with gardens and landscapes. Wood is also regarded as the best material for greenhouses. Wooden greenhouses are more expensive than aluminium or plastic greenhouses but are preferred by most experienced gardeners due to their natural look, better heat retention properties, strength and durability. Gardeners also favour a wood frame also because it is easier to fix and install shelves, hooks and other accessories.
Wood frames are generally larger and heavier than aluminium or plastic frames and therefore once constructed greenhouse expansion is difficult and expensive. Because wood frames are larger in size, increase the amount of shadow in the greenhouse, which means a decrease in the amount of sunlight that plants falling in the shadows receive.
Two types of timber are used for greenhouse frames-cedar and softwood. Cedar is widely used for its stability and effective resistance to rot and decay. Cedar wood also has better insulation properties than aluminium and it helps maintain a constant temperature in the greenhouse, which is very beneficial for the plants. During severe cold conditions cedar frames can also be fixed with plastic bubble sheeting for that extra layer of insulation. Softwood frames are cheaper than cedar but need very frequent maintenance.
Wood is most commonly used in homemade greenhouses. Its cost of maintenance is quite high due to which frames made of aluminium and plastics are now gaining popularity.
Wooden greenhouses are an expensive investment but they generally come with a ten-year guarantee. However, they have a limited life in the damp greenhouse atmosphere. It is advisable to coat the frames with preservatives every three years or so to protect them and increase their life.