Roof terrace waterproofing in Marrakech

A leak is not always located where the stain appears. Water follows slopes, ducts and beams and sometimes comes out far from where it got in. Diagnosis means tracing the path of the water back to its source.

• Brown stains or rings on the ceiling, especially after rain.
• Blistering paint, crumbling plaster, salt deposits or mould at the foot of upper walls.
• Areas of the terrace where water stands after rain: insufficient fall or a blocked outlet.
• Cracks, lifted tiles or open joints on the terrace.
• A musty or damp smell in a room under the roof.
• Damaged decoration: staff, painted plaster, swollen woodwork.

During the visit we examine the surface, the upstands against walls, the outlets, the penetrations for ducts, the air-conditioning units and old repairs. We also look for causes that have nothing to do with the terrace: a leaking pipe, rising damp, condensation. Our guide to damp in riads sets out these origins and what to avoid.

There is no single solution: the choice of system depends on the condition of the substrate, how the terrace is used (accessible, technical, garden), the look you want and your renovation plans. These are the families of solutions we study.

• Bituminous or synthetic membranes laid in several layers with upstands and covered with a protective layer.
• Liquid resin-based waterproofing applied continuously, suited to unusual shapes and substrates.
• Waterproofing beneath tiles: a system designed under the finish, useful when the terrace is tiled as its final surface.
• Thermal roof insulation combined with the waterproofing, to improve comfort in the rooms below.
• Targeted repair of joints and upstands when the whole is sound and only one point has failed.

Waterproofing should not be left exposed: solar radiation and ultraviolet light age it. It is covered with a suitable protection: slabs, tiles, gravel or reflective paint depending on the system. This finish is part of the works. For a finished floor, the page on tiling and zellige in Marrakech describes how we lay terraces.

• Repairing the inside (paint, plaster) without treating the terrace: the stains come back.
• Laying tiles or paint on a cracked or damp substrate without reworking the waterproofing.
• Forgetting to check the outlets: a few leaves or some sand are enough to block them.
• Piercing the waterproofing to install an air-conditioning unit, a parasol or an aerial, without a sleeve or repair.
• Letting terrace water run towards a threshold with an insufficient upstand.
• Waiting for the first rains before worrying: a regular check is far simpler.

Everyday care

Once the terrace is done, upkeep is modest but useful: clear the outlets and spouts regularly, clean the surface, watch the joints and upstands, and check after a rainy spell that no area is holding water. If you install air conditioning in Marrakech, have the supports and routes planned so that the waterproofing is not pierced. On request we offer inspections and occasional repairs after the works.