How much does it cost to renovate a balcony?
Balcony renovation costs range from around €50 to more than €1,000 per square metre, depending on the work required. A more precise estimate is possible only once the balcony’s size, construction, condition and the materials to be used are known.
The materials and extent of the work determine whether replacing the floor covering on a sound, load-bearing substrate costs around €50 to €100 per square metre, or whether new waterproofing with properly detailed junctions raises costs to around €150 to €400 per square metre. A comprehensive renovation involving concrete repair and a new build-up can reach €1,000 per square metre or more. Depending on the starting condition, work may include removing and disposing of the old floor covering; exposing and assessing the load-bearing structure; repairing damaged concrete and corroded reinforcement; forming or correcting a slope of at least 1.5%; waterproofing at doors and walls; reducing thermal bridging at a cantilevered slab where required; replacing the railing while meeting fall-protection requirements; laying a new floor covering; and finishing or cladding walls.
Once the old floor covering has been removed, the largest and often underestimated cost can become apparent. On cantilevered reinforced concrete slabs, water can enter through cracks and defective junctions. Carbonation and freeze-thaw cycles can cause reinforcement corrosion and concrete spalling. Exposed reinforcing steel must be cleaned of rust and passivated, and the concrete reprofiled, before the balcony can be waterproofed.
Before waterproofing, cracks, visible reinforcement damage or a planned increase in build-up height should be assessed by a specialist contractor or structural engineer. From a building physics perspective, a slope with functioning drainage and the junction heights are crucial. In accordance with BS 6229, waterproofing is carried up at door thresholds and adjoining walls, and should bridge cracks so that hairline cracks in the concrete do not transfer through it.
The connection to the building also determines whether additional insulation is worthwhile. Projecting timber or metal balconies on their own supports are already thermally separated from the building and therefore do not require insulation. A continuous concrete slab acts as a thermal bridge and can usually only be fully separated as part of wider conversion work. The choice of floor covering affects the work involved and future upkeep: ceramic tiles can spall in frost, timber requires intensive care and can rot, and WPC can become very warm and warp. Rubber tiles made from PU-bound Rubber granules are suitable as weather-resistant balcony flooring; they are free-draining and are laid on the prepared balcony without bonding.
This unbonded installation should be considered alongside purchase and laying costs, disposal, any concrete repair, and later upkeep and servicing costs when planning the total budget. This provides a basis for reliable long-term planning. WARCO rubber tiles made from PU-bound Rubber granules are suitable as weather-resistant balcony flooring.