The terrace is the part of the building that gets the most rain, sun and temperature changes, and in many buildings it also acts as the roof over the homes below. When its waterproofing fails, the water ends up on the neighbour’s ceiling or in the stairwell.
We waterproof terraces and roof terraces (terrados and azoteas), both private and communal, and both accessible and non-accessible, adapting the system to the condition of each one.
When a terrace needs waterproofing
- There are leaks or damp patches on the ceiling of the flat or premises below.
- Cracks, loose tiles or open joints appear in the floor.
- Water stands after it rains.
- The waterproofing is many years old or has already been patch-repaired several times.
There is no need to wait for a leak: preventive waterproofing extends the life of the terrace and saves you repairing ceilings, insulation and services afterwards.
Systems we use
Hot-spray polyurea
A continuous, jointless membrane that cures in seconds. It can be walked on within a few hours and is often applied over the existing tiles. More about polyurea.
Liquid membranes
Polyurethane systems and other continuous coatings, elastic and well suited to terraces with lots of junctions, parapets and outlets.
Sheet membranes
Bitumen membrane (roofing felt) in one or two layers, or synthetic membranes. This is the usual solution when the floor is taken up and the terrace is rebuilt.
Do the tiles have to come up?
Not always. If the tiles are well bonded and the substrate is sound, we apply a continuous system over the top and avoid the demolition, the rubble and a good part of the timescale. If there are loose tiles, the substrate is damaged or the falls do not drain the water, the right thing to do is to take up the floor, correct the falls, waterproof and retile. We tell you plainly once we have seen the terrace.
Communal terraces
In residential blocks, the terrace or roof terrace is usually a common element even if only one owner uses it, because it acts as the building’s roof. We work with property managers (administradores de fincas) and presidents of owners’ associations (comunidades de propietarios), and handle the whole process, from inspection to handover, with minimal disruption for residents.
How we do it
Inspection
We check the floor tiles, joints, outlets, parapets and falls, and find where the water is getting in.
Preparation
We clean, repair cracks and joints, seal the critical points and, if necessary, apply a primer.
Waterproofing
We apply the chosen system, paying special attention to outlets, corners and junctions with walls.
Inspection and handover
We check the result and leave you simple maintenance guidelines.
Price
The price of waterproofing a terrace depends on the area, the condition of the substrate, the system and access. We give you a detailed, no-obligation quote after seeing the terrace. If you would like a rough idea first, we explain it in how much it costs to waterproof a terrace per m².
From Viladecavalls (Barcelona) we work across Spain and on international projects.
Have a similar project?
We visit you, assess the building and give you a detailed, no-obligation quote.
Frequently asked questions about terraces
Can a terrace be waterproofed without removing the tiles?
In many cases, yes: if the tiles are well bonded and the substrate is sound, a continuous system such as hot-spray polyurea is applied over the top, with no demolition. If there are loose tiles, the substrate is damaged or the falls need correcting, the floor has to be taken up and redone.
What is the best waterproofing for a terrace?
It depends on how it is used and its condition. For terraces that are walked on, hot-spray polyurea and a double bitumen membrane under the tiles usually work best; on terraces that are not walked on, liquid membranes also give good results. We decide after seeing the terrace.
When can the terrace be used again?
With polyurea, within a few hours, because it cures in seconds. Other liquid systems need one or more days to dry, and if the floor is taken up you have to allow for the time the whole job takes.
How much does it cost to waterproof a terrace?
It depends on the area, the condition of the substrate, the system chosen and access. That is why we visit the terrace and give you a detailed, no-obligation quote.
