A gutter block is a wooden or metal block fixed to the end of the rafter or wall plate, on which a timber box gutter rests. The blocks carry the gutter, set its height and provide the fall needed towards the rainwater outlet.
Function
With a timber box gutter, the gutter does not sit loose but on a series of gutter blocks placed at regular intervals. By making the blocks slightly lower towards one side, a fall is created so that rainwater runs towards the outlet. The blocks also give the gutter shape and rigidity.
There is also a decorative variant: ornamental blocks (modillions) under the roof overhang, which support the gutter or cornice while also embellishing it. These are often seen on older houses and farmhouses.
Application
- Timber box gutters — the blocks carry the gutter along the eaves
- Overhangs — blocks under an overhang or cornice give support and rhythm to the facade
- Renovation — when repairing timber gutters, rotten blocks are replaced to restore the fall
Points of attention
- Use durable, treated timber; the blocks are exposed to moisture
- Check the fall when replacing: an incorrect fall makes the gutter overflow
- Provide good ventilation and drainage around the blocks to prevent wood rot
Related Terms
- Box gutter
- Gutter
- Overhang
- Cornice
- Eaves
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