Here we go with one of my most discussed topics in roofing over the past decade, metal roofs vs cedar shake roofs. I will break down the climate-driven reason as well as cost and longevity reasons, shake roofing is a dying material for roofs in the PNW.
Environmental/Climate:
The Pacific Northwest has a long history of using cedar shake as a common roofing material, as it has been the regional choice for over a hundred years. As the old-growth cedar reserves have been depleted and the new-growth cedar is not as durable as old-growth cedar, the market for cedar shakes has been transitioning to either composition or metal roofing. Cedar shake roofs do offer a nice aesthetic appeal and good breathability of a roof, but they do not last much longer than 18-20 years for medium thick shakes or 30 years on a Jumbo shake, in the temperate rainforests of the PNW.
Another issue facing cedar as a roofing option is the acceleration of climate change and polar shifts. Not to get into a political debate on the merits of climate change, I do have to acknowledge the very real warming of our summers over the past 8-10 years. As temperatures climb in the summer months so do the breakouts of wildfires. Cedar shake roofs have been known to ignite under such extreme heat conditions from the slightest spark of a cigarette or firework, or embers from a nearby wildfire.
Cedar shake roofs are known for needing a diligent and semi-annual roof maintenance schedule. cedar shakes will sustain organic growth in the form of moss, fungus (the black stuff you see), algae, and lichen growth. Needles from trees will get stuck in the channels between the shakes and on the edges or butts of the shakes. Regular blowing off of this organic debris helps minimize the growth of moss and fungus, but eventually, it will grow. Many cedar shake roofs need an annual low pressure clean to strip it down to a newer appearance and then have chemicals applied to preserve the shakes and inhibit moss growth, this adds to the environmental impact of the heavy maintenance these roofs need. Some will coat these shakes with oil-based treatments that will only exacerbate the issues mentioned above about warmer summers and roofs igniting. None of this is good.
Conversely metal roofs can be argued to be much more sustainable for our planet. First of all, there is no deforestation in harvesting the product, however, there is mining involved in the process of virgin steel manufacturing. Most sheet metal products (of which metal roofs are a part of), will use between 25-45% post-consumer recycled metal. Once the metal roof has outlived its lifespan it can be torn off and recycled into newer metal products. This process will only become more prevalent and the chances we see a 100% post-consumer metal product is very likely as we enter the era of sustainability.
Metal roofs are the preferred choice for areas that are prone to wildfires, for obvious reasons. We always recommend a High temp underlayment due to the heat absorption of metal roofs under UV exposure, but also to help insulate the substrate from potential fire hazards on top of the metal.
Metal roof cleanings are usually in the form of a blow-off with a leaf blower a couple of times a year, in heavily wooded areas maybe 3-4 times a year. there is normally no organic growth on metal roofs with the exception of algae stains and pollen, both of which will stick to the panels until it washes off over time or pressure washed or washed with eco friendly chemicals and rinsed off with a hose. It is the most maintenance-friendly roof system there is (well not discounting the safety of walking around on it, that is a different blog post under Best Safety Practices for Different Types of roofs, which I have not written yet).
Costs/Longevity:
Cedar shake roofs are more expensive than composition roofs and less expensive than metal roofs, but they also have a shorter life span than both of them in most cases (medium shakes). In most cases, when you install a cedar shake roof you will be paying about 35% less than a metal roof, but you will need to replace it 2 times before you even hit the pain warranty period of a metal roof! Let’s break this down:
2022 Cedar Shake roof cost: (costs are approximate and not based on a real estimate but just an average) 3000 sq ft
-Medium shake install material and labor=$22-25K
-Maintenace for shake roof over 20 year lifespan=$15-20K
2042 cedar shake install material and labor=
Who the hell knows! prices in last two years have soared over 45% to 100% in some materials! What’s it going to look like in 20 years? anyone’s guess, but for argument’s sake, I’ll add a 45% mark up. Let’s say 35-38K.
*You will have invested 70-80K into 2 roofs, possibly 3 (not including any tear off and disposal) for a cedar shake roof over metal.
2022 Metal Roof costs: (costs are approximate and not based on a real estimate but just an average) 3000 sq ft
-24 gauge standing seam metal roof Install material and labor=$30-35K
-Maintenace for a metal roof over 35-50 year life span=$3500-$4500.00
Next roof replacement between 2060-2070
So, if you are deciding what is the best option for your roof in regards to environmental impact, low maintenance, costs, and longevity there is no substitute for Metal roofing. It is by far your best investment now and in the future.