The roof structure is a key component and its exact design will depend on a variety of factors including the type and style of building, the size of the budget and relevant planning laws either on a national or local level.
Among the different types of roof available, generally there aree two different choices when it comes to planning an extension or construction project. These are flat roofing and pitched roofing, each of which has contrasting advantages and disadvantages.
Flat Roofing vs Pitched Roofing – Which is better?
Flat Roofing – Advantages
Design
Typically the design of choice for smaller structures, such as garages and extensions, flat roofing consists of a horizontal base which is fixed to the ceiling joists underneath with a waterproof membrane applied on top. While flat roofs are designed to hold standing water to some degree, a slight pitch of only a few degrees is usually incorporated to enable rainwater to drain away into a hopper.
Materials
Traditionally flat roofs have been constructed from asphalt or three-ply modified bitumen (also known as felt flat roofing) with a thin layer of gravel to protect the roof from the harmful effects of UV sunlight. A more recent and increasingly popular design is Ethylene Propylene Diene Monomer (EPDM), a 3mm thick rubber membrane which can be applied seamlessly in one piece and offers a lifespan of more than 40 years (compared to the 20 years for felt flat roofing).
Cost
Flat roofing is generally considered to be a more affordable option at the point of construction and involves considerably less materials and labour than a pitched roof. Full replacement of the roof, when the time comes, can usually be completed in a single day.
Flat Roofing – Disadvantages
Maintenance
With a lifespan for a felt flat roof of only 20 years, the prospect of having to maintain and eventually replace this type of roof can be off-putting, especially if you are seeking to sell your home. While the extended lifespan of EPDM is a definite improvement on felt flat roofing, some regard it to be an unsightly alternative that may not be in keeping with the style and traditions of the adjoining property or neighbourhood.
Pitched Roofing – Advantages
Loft Space
Pitched roofs, which have at least two slopes that rise to meet at a peak, are constructed in such a way as to afford plenty of usable space in the loft area, either as much-needed storage or even as additional living space, such as a study or playroom. In the process of designing the roof, any planned usage of this area can be incorporated into the plans so this type of roof offers an unmatched flexibility that a flat roof cannot.
Lifespan
The pitched roof, if constructed properly, is almost certain to offer a much longer lifespan than a flat roof, with materials that are more durable and weather resistant. The internal accommodation will be more efficiently insulated and will not suffer from the extremes of temperature that tend to afflict rooms under flat roofs.
Natural
Installing a pitched roof also means the building can be more effectively blended in to either the rest of the property (in the case of an extension) or to neighbouring buildings, while also helping to retain a sense of individuality and character.
Pitched Roofing – Disadvantages
Expense
Unfortunately one consequence of this is the increased expense, as the more complex design, additional building materials and extra man-hours cost significantly more than a flat roof.
Foundations
Pitched roofs also place a greater burden on the foundations of the building and this may have implications for the depth of the footings. Replacing a flat roof with a pitched roof on an existing structure is therefore not always feasible.
For pitched or flat roofing in London,
call Morgan Asphalte free on 0800 998 1378
Morgan Asphalte are experts in the installation and repair of all flat and pitched roofs, as well as fitting insulation and roofline products. Our qualified team have over 40 years of experience, so give us a call for the very best service at the most competitive prices in the area.