Rafter supported glazing bars are generally used on timber frameworks or rafters. These wooden rafters will fall from the higher to the lower part of the roof. Rafters create the structural strength of the roof
At this time of year when it is cold and damp many properties suffer from condensation. This is particularly as problem for older single glazed properties. This is both unsightly and unhealthy with damage often extending past the windows themselves. Curtains, blinds and the surrounding walls can develop dampness and even mould.
The good news is that this is an easy problem to solve. Ecoease Secondary glazing works by creating a layer of static trapped air between your cold glass and the inherently warmer PET glazing unit. As warm air falls within your room and hits the PET panel it doesn’t condense into moisture as it would if it hit the cold glass.
Provided you have created this static air you will reduce any condensation and in the vast majority
Going into April the weather is typically wet and still chilly! We are trying not to rely on central heatring as much as possible. Trying to reduce your energy bills with secondary glazing has never been more of a good idea. Energy prices are higher now than they have ever been! Now is the time to start thinking of cost effective ways to keep your home warm without raising your bills further.
We are often asked if you need planning permission for secondary glazing, or if it is permitted on Listed buildings. If the system makes permanent changes to the structure of the windows then it would be needed. However, our magnetically attached system is not classed as a permanent feature as you can easily remove it. This means no planning consent or permissions are required.
When designing your roof you need to be aware of the spanning capabilities of each thickness of sheet, in other words the maximum width of each sheet you should use. Lower thicknesses of polycarbonate sheet are not as strong or rigid when compared to thicker sheets, so the allowed unsupported spans are less.
To make things easier we have given the recommended maximum spans of each thickness of polycarbonate sheet below:
The maximum recommended spans by sheet thickness are:
Polycarbonate is a thermoplastic polymer that is strong and tough and can be easily moulded and thermoformed, in other words shaped by heating. Polycarbonate sheet can be made clear or can be tinted to different shades and moulded into sheets with a variety of thicknesses.
Once you have chosen the rafter bars for your timber roof you need a number of trims to complete the project. These will finish off your roof and give it that “professional” look.
Sheet End Closures
PVC Sheet end closures protect the bottom open edge of the polycarbonate sheet and prevent moisture getting up into the chambers. The sheet must be taped first to keep dust and insects out and then the sheet closures push on top. They are pushed onto the sheet between the Glazing Bars. If your roof is free standing rather than a Lean To, the top end of the sheet will also be open and will need sheet closures too. These sheet closures are vital as if you get moisture into your sheets it can create mould and turn the flutes black. These are available in white or brown or
Glazing Bars are used when you want to glaze a roof with Polycarbonate Sheets or Glass. You can have Rafter Glazing Bars or Self Supporting Glazing Bars and which one you choose will be determined by what type of roof you are looking to build.
The term Rafter Bar means that the glazing Bar will be fixed down onto an existing timber or steel rafter. These are the beams that come from the wall to the front of your roof or eaves beam. Rafter bars are fixed down onto the rafter and the polycarbonate sheets or glass are held in place with either a PVC or Aluminium Cap. If you are creating, replacing or refurbishing a timber framed roof then you should use Rafter Bars.
PVC Capped Rafter Bars are a lightweight, effective and easy to install method of glazing a roof. They are suitable for polycarbonate roofs but not for glass.
This type of Rafter Glazing Bar has a PVC Cap that is available in White, Brown or Anthracite Grey. This cap snaps down into an aluminium base which is fixed directly onto the existing rafter. Because of how the top cap is fitted, it is often referred to as a 'snap down bar' or a 'snap tight bar.' The bar comes complete with rubber gaskets and an end cap. The Gasket is fitted into existing grooves on each side of the aluminium base so that when the polycarbonate or glass is fitted it provides a snug waterproof fit.
There is a PVC Capped rafter bar that will glaze 10mm, 16mm and 25mm Polycarbonate Sheets and another Glazing Bar that accommodates 25mm and 35mm sheets, both of which are available in a range of different lengths.
PVC Capped Glazing Bars are simple to install. Begin by fitting the gasket into the grooves on the outside edges of the aluminum base. Screw the aluminium base into the roof rafter at approximately 300mm centres. Once the Aluminium base is fixed in place, locate a sheet of polycarbonate onto the gasket ensuring there is around 2.5mm gap between each edge of the polycarbonate sheet and the aluminium base’s central upstand. This allows for the sheet to expand and contract as the weather changes. Once your polycarbonate sheets are in place simply push the cap down to the required sheet thickness. You will hear a click or snap as the cap locks into place, hence this bar being known as a ‘snap down bar.’ The end of the bar can then be finished off by pushing the end cap into the grooves on the Aluminum base.
Self Supporting Glazing Bars are so called because they are able to support both themselves and the weight of the glazing material used on a roof. This means that they only generally need to be fixed at the top and bottom ends and not along their length which is the case for Rafter Bars. Self Supporting bars are taller than rafter supported bars, the vertical walls giving strength to the bar. Self Supporting bars are often used in conservatories, canopies, carports, walkways and other glazing applications. When using self support glazing bars you must check the bar snow loading table which shows the spanning capabilities of the bars, to ensure you place them at a safe distance apart. There are different maximum centres based on the projection of your roof and the glazing material you are using.
