Waterproofing a roof terrace can cost anything from around 20 €/m² to more than 150 €/m². The difference comes mainly from two things: whether the work can be done over the existing floor or it has to be lifted, and which waterproofing system is used.
Does the floor have to come up?
| Type of work | Guide price |
|---|---|
| Waterproofing over the existing floor | 10 – 50 €/m² |
| Lifting the floor in places | 40 – 80 €/m² |
| Lifting everything, waterproofing and laying a new floor | 60 – 200 €/m² |
If the tiles are well bonded and the falls work, a seamless membrane can often be applied on top, with no demolition: it is quicker, cleaner and considerably cheaper. If the tiles are loose, water has already got underneath or the falls do not drain properly, the floor has to come up. We explain this in roof terrace waterproofing.
Price by system
| System | Guide price | Comments |
|---|---|---|
| Waterproofing paint or liquid rubber | 10 – 25 €/m² | Cheap, but it is a thin coat that does not last long. |
| Bitumen membrane (felt) | 20 – 40 €/m² | The classic choice under tiles; joints and overlaps are its weak point. |
| Polyurethane membrane | 25 – 45 €/m² | Seamless and walkable, applied as a liquid. |
| Hot-spray polyurea | 30 – 70 €/m² | Seamless, with no joints, cures in seconds and is usually applied without demolition. |
| Mineral-surfaced bitumen membrane | 35 – 55 €/m² | For roofs without foot traffic. |
| PVC or EPDM | 30 – 70 €/m² | Synthetic membranes that stand up very well to the weather. |
Guide market prices, taken from price guides published in 2026 for complete jobs (materials and labour). They are not Catalana de Rehabilitació’s rates: the real price depends on the site visit.
Examples
- A 30 m² roof terrace in good condition, with a seamless membrane over the tiles: between €750 and €1,350 (30 m² × 25–45 €).
- The same terrace with the floor lifted and a new one laid: between €1,800 and €6,000 (30 m² × 60–200 €), depending on the floor chosen.
- An 8 m² balcony: the fixed costs of travel and preparation weigh more, so the price per metre comes out higher.
What makes the job dearer
- Many junctions with parapets, walls, doors and railings, which have to be detailed one by one.
- Outlets that need replacing or adding, and falls that need correcting.
- Removing rubble and carrying materials up without a lift or goods hoist.
- A substrate with cracks or hollow areas that has to be repaired first.
And who pays in an owners’ association?
If the terrace acts as the roof of the building, waterproofing it is usually the responsibility of the owners’ association (comunidad de propietarios), even if only one owner uses it. We explain this in leaks from a private roof terrace: who pays.
Have a similar project?
We visit you, assess the building and give you a detailed, no-obligation quote.
