Roof and Exterior Waterproofing in Cape Town

Roof Direct waterproofs the outside of buildings across Cape Town and the Helderberg: roofs, box gutters, parapet walls, balconies, concrete slabs, flashings, chimneys and exterior walls. We use torch-on and other proven systems, back the work with a workmanship guarantee, and aim to seal properties before the winter rain.

Where buildings leak

Roof Direct waterproofs the outside of commercial and industrial buildings, sectional title complexes and homes across Cape Town, the Helderberg and the West Coast. Our work is exterior only: we don’t treat rising damp or waterproof basements, which need different specialists. If water is coming in from outside, we’ll find where and stop it.

Most leaks start in one of these places, and finding the right one first saves paying to fix the wrong thing:

Flat concrete roofs, slabs and box gutters, where water ponds, membranes age and blocked outlets overflow into the building. See flat roof, torch-on and box gutter waterproofing.
Balconies, which leak into the room below. See balcony waterproofing.
Parapet walls, whose tops and joints take the full force of wind-driven rain.
Flashings, valleys, skylights and chimneys, where the roof meets something else.
Exterior walls, where rain soaks through and shows up as damp inside.
Cracks and expansion joints in concrete, which let water reach the reinforcing steel.

Parapet walls

A parapet is the part of an outside wall that rises above the roof line, the most exposed masonry on the building. Winter storms drive rain sideways into it, and in summer the south-easter and strong sun crack its plaster, capping and sealant joints.

They usually leak at a flat or cracked top, failed capping joints, the roof-to-wall flashing or cracked plaster, and the damp often shows on a top-floor ceiling some distance away, so we trace it back first.

We repair cracks and hollow plaster, give flat tops a fall, seal capping joints with Soudal sealants, waterproof the top with a liquid membrane or torch-on, and renew or reseal the flashing. The parapet and the box gutter behind it often fail together, so we check and quote both.

Flashings, skylights and chimneys

The roof sheets or tiles may have years left in them, but the joints with walls, valleys, skylights and chimneys take more movement and water. Flashings leak when the wind works them loose, when salt air rusts them near the coast, when the mortar or sealant holding them cracks, or when they were too short or lapped the wrong way. Skylights usually leak at the seals, frame fixings or upstand flashing, not the glass. Valleys leak when the lining rusts or debris blocks the channel.

We re-dress or replace failed flashings, reseal skylight frames and upstands, repair chimney flashings and tops, and clear or reline valleys, on tiled, metal and flat roofs. If the leak is part of a wider roof problem, see roof repairs and leak detection.

Exterior walls and penetrating damp

Penetrating damp is rain that soaks through an outside wall and shows up inside as damp patches, peeling paint and mould. In Cape Town, north- and west-facing walls take the worst of it from the winter north-wester, and tall walls, gable ends and upper floors get far more driving rain.

Rain gets through cracked plaster, porous brick and block, failed paint, badly sloped sills and cracked parapet tops, so it can be fixed from outside. We repair cracks with a flexible filler, replaster hollow areas, remove failed paint and apply an exterior waterproofing coating, with extra care around windows and joints. The wall is then painted in the colour you choose; see interior and exterior painting. Once the wall has dried, the stained interior can be repaired and repainted too, so one team looks after both sides.

Concrete cracks and expansion joints

A crack in a roof slab, balcony or wall lets water reach the reinforcing steel, the steel rusts, and rust pushes the concrete apart. Near the coast, salt air speeds this up.

Expansion joints are sealant-filled gaps that let large areas of concrete move. They leak when the sun hardens the sealant or movement tears it away, often causing a leak that seems to come from nowhere.

We repair cracks with products suited to each one, and cut out and reseal failed joints with Soudal sealants made for movement, before waterproofing over them. Concrete that has already spalled needs specialist repair, which we don’t do: we’ll point it out at the inspection, recommend a concrete repair specialist, and waterproof once the concrete is sound. If a crack is wide, keeps growing or runs through a beam or column, a structural engineer should look at it first.

Waterproofing systems we use

We match the system to the surface and how it’s used:

Torch-on membranes: bitumen sheets heat-bonded to the surface, a proven choice for flat roofs, box gutters and parapet tops.
Liquid-applied membranes and coatings: a continuous layer, useful on complicated shapes, balconies and walls.
Sealants: Soudal sealants for joints, flashings and details where movement has to be allowed for.
Over-tile systems: for balconies where lifting the tiles isn’t practical.

How a waterproofing job works

Inspection. We find where the water is really getting in, which isn’t always where the damp shows.
Itemised quote. Each area is priced separately, with the recommended system and guarantee.
Preparation. Failed layers are removed, cracks and joints repaired, and the surface cleaned and dried.
Application. The system goes on, with extra care at drains, upstands, joints and edges, where most failures start.
Sign-off. Andre or our foreman, Randall, checks the finished work with you.

Parapets and high walls often need scaffolding or, where that isn’t practical, rope access. Our teams are working-at-heights compliant, and larger projects get a health and safety file.

When to waterproof in Cape Town

Most of Cape Town’s rain falls roughly May to August, so late summer and autumn, when surfaces are dry, is the best time to waterproof. If you already have a leak, don’t wait: water damage gets worse and more expensive the longer it runs. The pre-winter roof checklist covers what to check first.

Commercial, body corporate and home waterproofing

Commercial and industrial: large flat roofs, box gutters, parapets and tall walls, planned around your operations. See commercial and industrial roofing.
Body corporates: balconies, parapets, walls and roof slabs, quoted area by area so trustees can prioritise. See body corporate roofing.
Homeowners: leaking balconies, flat roofs and damp walls, fixed properly the first time. See roofing and waterproofing for homes.

Get a free waterproofing quote

Request your quote, call us, or send photos on WhatsApp.

Frequently asked questions

How long does waterproofing last?

It depends on the system, the surface, how exposed it is and how well it's maintained, which is why we recommend a system for your surface rather than one product for everything. Our waterproofing workmanship is guaranteed for 1 to 4 years, depending on the job, and the terms are set out in your quote. Regular checks of drains, joints and flashings help any system last longer.

What does waterproofing cost in Cape Town?

We don't publish prices, because the cost depends on the job. The main factors are the area to be covered, the condition of the surface and any existing system, the waterproofing system chosen, access and height, and how much repair work is needed first. After a free inspection you get an itemised quote that shows each area separately.

How can I tell rising damp from penetrating damp?

Look at where the damp is and when it appears. Rising damp sits in a band along the bottom of a wall, often with a tide mark and white salts, and stays there all year. Penetrating damp can show up anywhere on the wall, often around windows or high up, and gets worse after rain. We treat penetrating damp only, from the outside.

Why do parapet walls cause damp inside?

Parapet walls cause damp inside because rain soaks into the top and face of the wall and tracks down through the brickwork into the walls and ceilings below. The usual entry points are a cracked or flat top, failed capping joints, a failed flashing where the roof meets the wall, and cracked plaster. The damp often shows on the top floor, some distance below the parapet.

What is concrete spalling?

Spalling is when pieces of concrete crack and break away from the surface, often exposing rusty reinforcing steel. It usually happens because water has reached the steel, and rust takes up more space than the steel did, pushing the concrete off from inside. Spalling repair is specialist concrete work we don't do, so we point it out at the inspection and waterproof once it has been repaired.

Can waterproofing be done in winter?

It can, but only on dry days, because most systems need a dry surface to bond properly. That makes winter work slower and harder to schedule, which is why we suggest sealing roofs in late summer and autumn, before the rain sets in. If water is already coming in, call us: we offer emergency call-outs for active leaks, and we plan the full job for the first suitable spell.