Balcony elements may be watertight or water permeable. The first type is more common because usually there is a terrace or another balcony below the balcony.
The load-bearing elements of the balcony consist of pillars and beams, the choice of which depends on the width of the span and the architectural solution. Balconies are subject to strict requirements regarding load bearing capacity and sagging. Snow loads also need to be considered.
Water permeable balcony element
The principal solution of a water permeable balcony is similar to that of a terrace: spaced impregnated floorboards are screwed to impregnated floor beams forming the floor element of the balcony. The cross-section of the beams is chosen based on the width of the span.
The accompanying image shows a principal solution for a water permeable balcony element.
Watertight balcony element
The floors of watertight balconies are built with two elements: the load-bearing element consists of floor beams onto which an element made of boarding or building boards and rolled bitumen material is attached. Onto that an element consisting of impregnated floorboards and impregnated wooden battens is attached. To allow water to flow away from the bitumen material layer, the floor beams of the lower elements and the wooden battens of the top element have been cut at an angle so that the balcony floor stays horizontal.
The accompanying images show two possible solutions for watertight balconies.
Terraces are produced from impregnated wood. The terrace element consists of boarding and the battens that hold them together. Two main solutions are used depending on the terrace foundation: tightly placed concrete pillars or belts onto which the terrace elements are installed, or spaced concrete pillars onto which impregnated wooden beams are installed with the terrace elements being installed onto them. Generally terraces are not watertight and rainwater seeps through the terrace boards into the ground.
The terrace will be provided with barriers when the architectural project requires it or when barriers are necessary for safety reasons – if the terrace is more than 0.5 m above the surrounding ground.
The accompanying image shows a principal solution for a terrace element.