Do’s and Don’ts

Taking the RISK out of choosing a Natural Roofing Slate

Jim O Donoghue, Director, Killoran Slate & Tile.

To get a beautiful long-lasting roof you need best quality Natural Slate and equally important you need a professional Slating Contractor who has experience fixing NATURAL slates. Remember we are talking about a life expectancy for the roof of at least 100 years which is equivalent to three Generations.

  • Which is more important ? A nice stone wall feature  or a beautiful  stone (natural) slate on your roof ?
  • Avoid roofing slates with no name. Avoid crates of slates without labels.
  • Don’t rely on samples – Go to the suppliers DEPOT and check your slates in the crates prior to delivery.
  • Be aware of “ Passing off “ i.e being offered a Spanish slate but delivering a poor quality Chinese or Brazilian slate.
  • Be very suspicious of low prices – if it LOOKS like a slate does not mean it is a GOOD slate !
  • Salesmen “pushing” the HOOK system usually have a concern about slates falling off.
  • Ask at least 3 experienced SLATERS for prices to slate your roof. Take a close look at their reference jobs.
  • Some slate importers are tending to take a short-term view of quality standards.
  • Customers focusing purely on the price per slate, are easily distracted from the primary consideration –  the long-term life expectancy of the slate on the roof.

Most crates are 1200mm x 1000mm, so the quantity in the crate often gives a better indication of the SELECTIONs than the name on the Label. Dont be fooled

SSQ Selections in size 50×25  are as follows:- ULTRA = average 800 per crate. 5mm thickness.

FIRSTS = average 720 slates per crate. 5-6mm thick. CELTAS = average 620 per crate. 5 – 7mm thick.

HEAVIES = average 540 per crate. 7 – 9 mm thick. HEAVY Ultra = average 480 per crate. 8 – 10 mm thickness.

SSQ Selections in size 60 x 30. FIRSTS = average 580. CELTAS = average 510. HEAVIES = average 460 per crate.

  • Buy a well known BRAND, like SSQ,  with a proven track recordin UK and Ireland’s climate.
  • Ask for Certificates of Conformity, CE certification and Declaration of Performance.
  • Buy the GRADE of slate which is best suited to the weather exposure in your geographic location.
  • Buy from a long established Roofing Supplier who is honest, reliable and trustworthy.
  • Look for roofs more than 20 years old with the same slates used as you are being offered.
  • Look out for any staining indicative of unstable PYRITES leaching from the slate.
  • Look out for any cracked or replaced slates on relatively new roofs.
  • Look out for FADING ( varying shades of grey )  on natural slate roofs – best quality natural slate does not fade.
  • Use only HEAVY Grade slate in areas of  Severe Exposure along the West Coast of Ireland
  • Do use an experienced Slating Contractor who will, Sort, Grade and FIX the slates properly.
  • Are you happy with your SUPPLIER’s reputation to deal with product COMPLAINTS.

It is generally accepted that the roof of a building should outlast the useful life of the building, given routine inspections and maintenance. It should be noted that few other roofing materials match the long life of best quality natural slate. It is all too easy to fall prey to the clever roofing materials sales person who seldoms deals qith QUALITY, TRACABILITY and PERFORMANCE and who constantly emphasises the cheap price of the slate roof. There has been a concerted effort by the Department of the Environment, the Construction Industry Federation and Construction Professionals to provide, long overdue, and  much needed consumer protection.

Every crate of SSQ – Del Carmen slates is clearly labelled and carries a Del Carmen Barcode which enables tracability back to production at the Del Carmen Quarry,located at  La Bana, LEON, Spain. Each crate shows a CURRENT valid Declaration of Performance. Each crate carries the mandatory CE marking. The foregoing comply with the requirements of the revised CIF-HOMEBOND insurance scheme.

As one can imagine, we have seen some real disastrous roofs with more than 35 years in the slate business. It never ceases to amaze us that customers spend thousands of Euros to put natural slates on their roofs, and then after a few years, they don’t know the name of the slate and can’t trace the slate producer when they have a complaint. Take for example the customer who arrived into our Depot with a sample slate in her hand, looking for a matching Spanish slate as she now wanted to roof her garage. She had bought around 6,000 slates for her home about 4 years before. She was now looking for 600 ” matching ” slates for the garage. The slate in her hand had deteriorated because of frost damage.

Instead of buying 600 slates for her garage she was now facing the unpalatable task of buying another 6,000 slates for her house and then paying a Slater to strip and reslate. She was sicker still when she said she had bought the dearest slate in the Merchants yard because she expected that price reflected quality ?

Down the years we have seen a plethora of imitation slates as well as novel ” systems ” for fixing the slates to a roof. Plastic slates, rubber slates, tiles that look like slates, fibreglass slates, Glass reinforced concrete slates, Each new arrival was supposed to be ” the greatest thing since sliced bread ” !!! . Their paper credentials and test reports were quite convincing. The ” missing link ” common to each was true performance in use over many decades in the Irish climate. We had many invitations to stock and sell those imitation slates but we always concluded that our reputation in the roofing industry was far more valuable than a ” quick buck “.

So the moral of the story is to buy a well known BRAND  ( SSQ ) from reputable Distributors ( Killoran Slate & Tile ) and rest assured that you have a long term roof on your home.

Ask a Question.....

If you have any queries or questions, ask us about any of our roofing products.