The Sod Roofs of Norway

Everywhere in Norway, there are beautiful sod roofs, a practise that has been rooted in tradition since pre-history.

 I just had to learn more about them, especially when I read that Doukhorbours in the old country also used sod on their roofs.

 Green roofs are shimmering with long, healthy grass; rainbow-coloured roofs with purple, blue, pink & white lupines; or with delicate wildflowers; roofs with yellow buttercups; and others that glow golden with grains waving gently in the breezes.

Some roofs have trees growing them:

I found several websites with information and have tried to put it together briefly and accurately.

The roofs range in size from very large to very small ones protecting signs.  Many protect log homes, but many are also over modern places.  They are mostly in the country on farms and outbuildings, but we have seen them in every city too.

On a large building:

Sod roofs are very heavy (250 kg/m2 & can be double that with a snow load!).  This weight is an advantage in log building construction as it compresses the walls making them more draught-proof and keeps them straighter.

The roof has great insulating properties.  The average lifespan is 30 years, but some have lasted generations.

To my surprise, the roof is not about the sod.  It's the layers of birch bark underneath that provide the water-proofing and longevity.  The sod merely holds the bark in place.

Generally, 6 layers of birch bark were used, but up to 16 have been documented.  The bark is laid directly on the roof without nails.  Because of the tendency of bark to curl, 2 people had to work together ... one laying bark and the other with the layer to weight it down.

The first layer of sod is put grass side down (which protects the bark from acidy humous), followed by a layer grass side up (these roots eventually permeate the bottom layer to form one solid layer).

Extra-long pieces had to be used at the peak to straddle the ridge.

The bark has to project beyond the roof edge so that it curls around the outermost board to form a 'throating':

Sod roofs were very labour intensive but inexpensive.  Just as people in North America used to have barn raisings, here the neighbours would get together when someone needed a roof.

Today with the 'green' and the 'preservation' movements ... along with the demand for mountain lodges and holiday homes, sod roofs are reappearing as an alternative to modern building materials.

At an open-air museum:

Perhaps one day I will get around to a post on the functional and decorative slate roofs of Norway.