If you have a slate roof or are thinking about investing in one, its important to understand how to care for it. This will help you make informed decisions about maintenance and repair. It will also help you to defend against contractors who prematurely attempt to condemn it.
Benefits of Slate Roofing
Slate roofing is fireproof, waterproof, natural, long-lasting, and beautiful, with a history that dates back thousands of years. When properly installed and maintained, slate roofing can last 150 years or longer.
Elements of a Slate Roofing Systems
A slate roofing system consists of the roof deck, roof flashing (where appropriate), slate, and nails.
A strong slate roof will be constructed with the following materials:
- hard slate: hard slates won’t be as susceptible to hairline fractures and cracking, and last longer than soft slate
- board roof deck: this should not be laminated
- flashings: metal joints around chimneys, near dormers, protruding pipes and valleys that are made from copper or stainless steel
- nails: nails need to be made from hot dipped galvanised steel, stainless steel or copper.
Slate Roofing: What to Avoid
The first rule in slate roof maintenance is never to coat the slate. Prior to coating, the slate would need to be pressure washed, which significantly reduces the lifespan of the slate tile. Coating is expensive, ineffective, and needs to be replaced every 3-8 years. It also requires contractors to walk over the roofing several times, which exposes the tiles to further cracking.
Also avoid spilling tar, slates that do not match, and metal patchwork. Contractors should never use roof cement or mastic to repair a leak. Instead the individual damaged or cracked slate should be replaced. Avoid ‘face-nailing’, in which contractors or home owners nail through the exposed face of the slate.
Good Slate Repair Practices
Good repair practices include replacing broken tiles, matching replacement tiles appropriately and preventing people from walking on your roof. Proper maintenance will help you to avoid leaks and preserve the longevity of your slate roofing system. Standard repair techniques include the ‘slate hook’ and the ‘nail and bib’ approach. Avoid exposed strap hangers, which will bend, flatten and comprise the replacement slate. Slates do need to be replaced if they crack, leak or slip out of place.
For more information about slate roofing or to schedule your next slate roofing project, contact Loftworld today.