The design of a pergola depends on the geographical location. Depending on the area, the grade or the direction of the sun, a pergola may be a gazebo, an extension of a building, an open terrace or a veranda that has grapevines criss-crossing a latticed roof. One of the most important considerations when designing a pergola is the roofing structure and shape
The roof design on a pergola depends on the availability of direct sunlight as well as the geography and natural features of the region. Although, in earlier times, pergolas were constructed using brick and stone pillars, modern designs employ weather resistant woods such as western red cedar or coast redwood. Pergola roofs may range from simple, flat, traditional roof, elaborately curved roof, pitched roof, gabled roof or a gazebo style roof.
There is a variety of materials that may be used to roof a pergola. The choice of roofing materials depend on the size, shape and style of the structure. The durability and robustness of the construction depends on the materials that are selected for this purpose. Currently the materials that are used for roofing include metals, plastic, fibreglass, polycarbonate, fabric, etc.
The advantage of a metal roof is that it can be adjusted to the exact size and shape of the structure. A choice of metals such as copper, aluminium or tin also helps to make an easy decision. Metals not only easy to cut and shape, they also provide excellent protection from the weather conditions. However, they also have some disadvantages such as disallowing light to enter the area or enabling the temperature to get too hot inside the area.
Plastic and Fibreglass
Another variation of roofing for pergolas includes using plastic or fibreglass. The advantage of these options is that they are lightweight and inexpensive. They may also be easily cut to size and allows the light to filter in depending on the colour of the roof. They also protect the pergola from the harsher elements of the weather including the rain and snow. Also, ultraviolet radiation may be reduced when using these two options. Although plastic may not be a green choice, Fibreglass can be manufactured from recycled materials.
Polycarbonates are thermoplastic polymers which can be easily moulded and has a high impact resistance along with other advantages such as heat resistance, ease of shaping, flame retardancy and toughness. They are available for varying needs of heat transmission and transparency. Polycarbonates are also highly reputed for their protection from ultraviolet radiation. Along with a wonderful combination of colours to choose from, Polycarbonate can be manufactured to resist very specific and harsh environmental conditions in Australia. The two popular brands that are in use are Astrolite and Laserlite.
Everyone loves a colourful and pleasing roof that can uplift our spirits and enable us to enjoy the day. For this reason, fabric pergola covers which are also highly insulating may be an amazing choice. Depending on the type of fabric used, these pergolas may avoid the transmission of heat which could cause fading or damages to the roof. A tough and durable fabric that may usually be used in the making of the sails of a boat can also be used to filter ultraviolet rays and other harmful natural elements such as sunlight and heavy rain so that people can enjoy their investment for a long time.
Comparative Study of Roofing Materials for a Pergola
Permanent structures like metal roofs are difficult to change but they can be repainted. Fibreglass and clean plastic materials may change colour after a period but they can be discarded and new ones can be installed easily. The choice of materials to cover or roof the pergola depends on the buyer’s instincts as to the choices for durability, permanency and availability. In tropical Australia, zinc-galvanized corrugated sheets do not reflect infrared or ultraviolet much. White roofs reflect better. White or soft shades are better colors for a cool roof. As the Earth seeks to get greener, the best choice, of course is to enjoy traditional, open roofed pergolas.
Painting your Pergola
Anything that is exposed to the harsh elements of nature will eventually need protection. Painting is one of the best ways to provide this protection. It gives colour to the wood and also conceals some of the natural defects and characteristics that may stand out obscuring the real beauty of the wood. Paint is also beneficial because they prevent moisture damage and rust. Acrylic paints are the best choice for painting pergolas as they provide the best protection.
The durability of pergola depends on the materials chosen for its construction. As the roofs are permanently exposed to the elements of nature, the paint chose may fade easily. Also, materials such as fabric may fray or fade and plastic or fibreglass roofs may get warped or change colour.
To paint a pergola for lasting protection, it is important to follow the traditional procedures such as preparing the surface which include removing old paint, using sandpaper to permit absorption and applying preservative towards the end of the painting. Preparation of the surface is very important before painting as it decides how much time the effect of painting will last. Any remnants of oil or dirt on the surface of the wood should be removed thoroughly. Using sand paper with 50-60 grit, create an appropriate surface for good absorption of paint. If the wood is more than two weeks old or if it had been lying outside in rain, sanding, brushing and cleaning becomes essential. Application of a water repellent preservative with fungicide is an excellent idea before painting because it prevents absorption of water by wood which may cause decay.
Here are the steps to paint a Pergola:
- Remove the furniture and any decorations you may already have.
- If there are growing and climbing vines, protect them with plastic sheets and tie them up so that they will not be in the way. Also remember to water them if the painting takes more than a few days.
- Wear a mask, a head cover and protect your eyes with safety glasses. Also wear an apron or old clothes to protect from paint splashes.
- Using sand paper, remove all paint until the surface is completely prepared.
- Apply a water-repellent and fungicide if necessary.
- Using a paint-sprayer, spread evenly from the farthest end to the back. High Volume Low Pressure (HVLP) sprayer is more efficient and smooth.
- Use a paint roller to get a smooth finish.
- Give a light coating on the roof of the Pergola.
- Fill in the gaps and allow the paint to dry for up to four hours.
- Apply a second coat of paint on the roof of the pergola.
- Allow the paint to dry overnight.
Causes of Discoloration of Pergola roofs
Over time, Pergola roofs may get discoloration due to dirt, fungus, mildew or moisture. Also, any iron fittings may rust and cause red stains which may react with other pigments or stains. To prevent this, stainless steel nails may be used and a constant vigil kept to encourage the Pergola to stay dry. A commercial mildew remover or other multi-purpose cleaners and help keep the roof spotless. Stains that are caused by the reaction of water deposits on the wood may also be removed by washing it with cleaners. Chalking is another form of discoloration which is caused by weathering of paint or disintegrating of pigment particles, which appear as a powder. Restoration painting necessitates cleaning by paint strippers, bleachers and oxalic acid based solvents to remove stains.