Pergola / August 27, 2018 / JulietteHughes
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.
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. Polycarbonate 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.
So while buying wooden pergolas ask their manufacturers if they are partially notched or fully notched. Buyers should be aware that notching creates interlocking joints and this fortifies the structure. Also notching insures that all your timbers stay straight and true over the decades because they cannot move. Most manufacturers skimp on notching partially or completely to reduce their construction costs and will tell you that hardware will take care of the issue. It does not. If just one of your Pergolas timbers has hidden stresses in it (quite common) as it weathers over the years it will turn twist or sag.