Torvtak: The Grass Roofs of Norway
A traditional and practical design that’s seeing a resurgence
We recently moved into a house with a grass roof, which we thought was pretty neat, but it got me wondering a bit about the purpose of grass roofs and what their history in Norway is. Torvtak are the grass roofs of Norway. Traditionally built using layers of birch wood underneath sod and grass, they provide improved insulation and warmth for log homes of centuries past. And, they’re seeing a resurgence with the Green Movement in Norway today.
Our house is warm and was downright hot over the summer when temperatures reached well into the 80s and hovered around 90℉, we can attest to the insulation capabilities of this style of roof. I’m also sure the fact that our house is newer by Norwegian standards and seems to have been built for cold weather helps too. Needless to say, I’d be surprised if we need to use our fireplace for anything but ambiance this winter.
The roofs don’t all look similar either. Ours is filled with tall grass that’s currently brown, some succulents, and the occasional flower or weed. But, I’ve seen many lush, green roofs blanketed with grass and some that even have trees growing out of them. There is a wide range of what is grown on top of these turf roofs, but they all have a goal of providing warmth and a greener, more environmentally friendly option these days.
While insulation is a major factor and benefit to using a turf roof, they supplied other benefits to early builders as well. They provided a waterproof barrier to the interior of the home, which is important in the wet and rainy environments of Norway. The roofs are heavy and this weight allowed for a sturdier home build compacting logs together more tightly. A turf roof provided a longer-lasting option for shelters.
Today these roofs provide a green and environmentally friendly option to home builders. Having a roof covered in plants and foliage creates for cleaner air, cooler surrounding air temperatures, greater habitat biodiversity, and lower energy costs. Our roof seems to attract lots and lots of spiders which build webs all over the exterior of our home. I suppose this maybe helps to keep other, more pesky bugs away, but having loads of orbweavers hanging around isn’t ideal for the creepiness factor at night. We also get more birds on our roof now than we did before with the normal roof at our old house. This isn’t a bad thing, just an observation.
To me, the green roofs are also aesthetically pleasing, especially in more lush and green landscapes. The homes and cabins tend to blend in with the surroundings a bit more. It’s also fun to see the variety of plants that may be growing on top.
Fortunately for us, we do not need to worry about the upkeep of our roof since we are renting our home. We did talk to the owner about this though. We were told maintenance is done twice per year by professionals. They come in to clip down overgrowth and make sure the roof is still structurally sound. I’ve seen videos of home owners getting on their roofs and mowing down the grass using long grass hooks or scythes, which seems quite labor intensive. I’m thankful we don’t have to worry about this aspect of having a turf roof at this time.
The turf roofs in Norway are more common in rural areas and on cabins, but they are starting to appear on houses a little more often with the green movement. Who knows, maybe we’ll opt for a green roof option in a future home build.
