Irish Rain: Keeping Ireland dry

By The Helpful Engineer / On / In New Building Issues

Irish weatherIt is often said about Ireland’s wet and mild climate that ‘it would be a great Country if you put a roof over it’. People saying this often forget that it is the wet weather that makes the countryside look so alluring in the first place.

Ireland’s rainfall is spread relatively evenly throughout the year, with seasonal rainfall amounts being similar in most parts. Surprising the wettest month of the year in Dublin, which is the driest region of the Country, is August, while February is the driest. I think the reason that this seems strange is because a dark cold month like February feels damper, with any rain lying on the ground taking a long time to dry.

Evaporation. This in fact is the main reason that flooding is more likely to occur in the winter. It is not the higher rainfall in winter which causes more flooding then; it is that the much reduced evaporation in winter months results in more rain entering the watercourses. It has been calculated that the evaporation in the brighter six months of the year (April to September) is 5 times that of the winter six months. Evaporation usually exceeds rainfall in the months May to July. The river levels usually remain relatively high however by drawing down groundwater and lake levels. Source ‘Irish Rivers’ edited by the late Eamon de Buitlear.

Dealing with the wet weather. So while we all recognise that the Irish climate is wet and particularly damp for six months of the year, why isn’t there more allowance for rain in our building design? It is strange but most building designers don’t seem to make enough allowance for the wet climate. Although some have suggested that our towns could be roofed, to spur business, by keeping shoppers dry. The expense of this would make it impractical. But we could cover small areas to make all our lives easier. This could be done for relatively little cost, some examples:

  1. Cover play areas. Children’s playgrounds, basketball courts, five aside pitches, putting greens etc. could all be covered. If these were covered with a relatively inexpensive roofing material they would be used more. A translucent roof would be ideal so that the play area remain bright. It would be particularly useful for children’s playgrounds. While children might simply put a rain jacket on if its raining, they aren’t going to play on wet slides and see-saws.
  2. Cover railway station platforms, bus stops. It is amazing that when railway stations are upgraded no roofs are installed over the platforms. My local railway station has a rain shelter that can fit about ten people inside it, while anything up to a hundred wait in the rain for trains during the morning rush. Its the same for bus stops, Bus Eireann and private bus operators rarely provide bus shelters although Dublin Bus do.
  3. Canopies for office buildings, hotels. These are rarely provided, but if installed, they are often installed so high above the ground that they offer little protection against windblown rain.
  4. Provide car ports and cover car parks. Every house with a driveway in Ireland should really have a covered car port. They are perfect for walking between the car and house, and unloading the car without getting wet. Also car parks are very poorly served with rain shelters; not only are the walkways rarely covered but the trolley bays can be left uncovered, which results in wet trolleys being pushed around supermarkets.
  5. Covered stadiums. A roof should be considered for the most important stadiums to protect the fans and the pitch. Interestingly Ireland’s loss to England in the Rugby Six Nations was being partly blamed on the wet pitch surface.
  6. Pedestrian bridges.  I can’t think of an example of a pedestrian bridge in Ireland with a roof, but roofs over bridges may have other advantages, as they would presumably help to slow the rate of corrosion of the bridge structure.

There are added benefits of installing shelters. In the case of the railway station platform, if the platform is sheltered from the rain, ice can’t form in winter and therefore no salt is needed to be spread on frosty mornings to keep the platform free from ice.

2 thoughts on “Irish Rain: Keeping Ireland dry

  1. The construction industry has the necessary construction materials and know how to facilitate these ideas – particularly the playgrounds etc.
    We in Bidcon, being a specialist roofing contractor, would make our engineers / detailers available (free of charge) for any meeting on this aspect of ‘protection from the elements’ that might spring from such a worthwhile proposal.
    The following elements would need careful consideration
    – Structural integrity
    – Materials choice – Transparancy of roof finish to avoid costly lighing overheads, longevity, maintenance and vandalism
    – Access to the roof – design the perimeters to ensure general public cannot climb up onto the roof
    – Drainage of the roof

    I have spent many a wet afternoon indoors rather than the healthy outdoors after having to return home from an unsheltered playground with my 4 children.

    Ed Cronnelly – MD/Owner
    Bidcon – Roofing and cladding Specialist Company.

  2. It’s all theoretical. Civil Engineer’s design charts date back to the 1980-90s and the recent summer floods due to Global Warming and freak storms is just too much for the Storm Water System. If places get flooded it’s a lack of flood defense and not poor Engineering. Local Councils have been allowing too much flood plain development in the last 20 years, leaving people low and wet, as opposed to high and dry.

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