26 Apr 2016

Eurocell uncovers roofline terminology


Roofline components are the essential parts of your roof that protect your home from the weather – mainly wind and rain in the case of the UK. Chris Coxon, Head of Marketing at Eurocell, explains what they are, how they work and discusses what materials to choose.


With the possible exception of drains, roofline products are the parts of a building that few people notice until they fail because they are hard to reach and often out of sight. But the five main elements – fascias, gutters, soffits, bargeboards and boxends – are essential as they bear the brunt of anything the weather has to throw at them.

Fascias, in particular, protect the roof space and rafters of the home and, if allowed to rot, can lead to roof rafters being damaged – as well as spoiling a home’s appearance if they are old and discoloured. The fascia board is the long, straight board that runs along the lower edge of the roof and is fixed directly to the roof trusses. It needs to be structurally strong and durable because it not only supports the bottom row of roof tiles, but also carries all the guttering – and all the rain that sweeps into the gutters from the roof.

The larger the roof area, the greater the volume and weight of water that runs into the gutter when it rains. As a result the fascia board may have to support many kilos during a downpour.

Everyone knows what a gutter – sometimes known as an ‘eaves trough’ – is: simply a narrow channel at the edge of the roof that collects and diverts the rainwater. This is then directed via a downpipe (sometimes called a leader or conductor) from the roof edge to the bottom of the building where it is either discharged into the sewage system or collected. Some sustainable building designs collect rainwater for uses that do not require drinking water, such as flushing toilets or washing clothes.

Soffit is a general construction term that refers to the underside of a flat, horizontal surface but, in roofing terms, means the board that covers the space between the external wall of the property and the edge of the roof. Soffit boards are usually screwed or nailed to rafters, known as lookout rafters, and abut the fascia board, so they are usually made of matching materials.

The amount by which the soffit board extends beyond the external wall varies a lot, depending on the design, from a few centimetres to more than a metre. In some cases the soffit boards are ventilated. In other climates this is so they can cool the attic space, but in the UK the ventilation slots are designed to ensure that your loft is well ventilated at all times, preventing damp and protecting the rafters from rot.

The gable end of a house or terrace has a bargeboard under the roofline. Historically, bargeboards were fixed to the projecting gables of a roof to give them strength, but now they are both cosmetic and protective because they cover the ends of the horizontal timbers or purlins of the roof to which they are attached. Without the bargeboards, the timber ends would be exposed, which would both look very poor and would expose the timbers to rain and rot. The condition of the bargeboard can often make or break the look of a house, and over the years it has evolved into some very attractive shapes.

Boxends are also found on gable ends, where they accommodate the fascia, soffit and bargeboard at each corner of the house into a neat, tidy right-angled shape: the roofing equivalent of a ‘hospital corner’.

All five of these elements must work together because if one fails then it has an impact on the others and, eventually, on the performance of the roof. There is a wide choice of models and materials for gutters, downpipes, fascia and soffit boards, such as low-maintenance PVC-U. While every self-builder wants an attractive product, there are more practical factors to consider such as weight because, assuming the building is more than one-storey tall, someone has to heft all the materials.

Construction professionals use an approach called Whole Life Costing (WLC) to select building components and, while it is intended for commercial and industrial buildings, it is a powerful tool for calculating the lowest cost options for the entire life of a building. In the case of roofline products, it means that you should look at maintenance costs, and the cost of access in particular, when assessing which material to use. Updates to the Working at Height regulations mean that jobs that could once be done from a ladder, such as painting soffits and guttering, now require either scaffolding or a ‘cherry picker’ (an elevated work platform).

So, the materials need to be both maintenance-free and durable to represent good value for money. The products that meet these criteria will often carry a 10 year or 20 year guarantee as well as being manufactured by companies that have some history behind them. These products may not be the cheapest option in the short term but will save you the hassle and the expensive bills for repair and maintenance over the life of your home.

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