Roof Waterproofing Before the Rain: A Simple Guide for Jeddah

Jeddah does not see much rain, but when it comes in the cooler months it can be heavy, and flat concrete roofs that have dried and cracked over a long summer are where leaks start. Water that gets into the slab damages ceilings, paint and electrical fittings, and it rusts the rebar inside the concrete.

The good news: a roof waterproofed properly before the rain will stay dry for years. Here is what to check and how the job is done.

1. Check the roof first

Walk the roof and look for:

• Cracks in the screed or around the edges of the slab
• Old membrane that is lifting, blistered or torn
• Ponding: areas where water would sit instead of draining
• Blocked drains full of sand and dust
• Gaps around pipes, AC stands and parapet walls

Small cracks can be filled; large areas of failed membrane need replacing.

2. Prepare the surface

Waterproofing only works on a clean, dry, sound surface. Sweep away all dust and sand, remove loose material, and repair cracks and broken screed. Make sure the roof falls towards the drains so water does not pond.

3. Prime the concrete

Apply a cold bitumen primer such as Awazel D41 asphalt primer by brush or spray. The primer soaks into the concrete, binds the dust and gives the membrane a strong surface to bond to. Let it dry before the next step.

4. Lay the bitumen membrane

Lay bitumen waterproofing membranes over the primed roof, overlapping each roll at the sides and ends as the manufacturer specifies. Turn the membrane up the parapet walls and seal carefully around drains and pipes, as these details are where most leaks start.

5. Protect it

Exposed membrane ages faster in the sun. Protect it with a screed and tiles, a protection board, or a reflective coating as the roof design allows.

Other products for the job

• Cementitious waterproofing such as Saveto Vetoproof for wet areas, water tanks and smaller details
• Polyurethane sealant such as Saveto Vetoflex PU780 for movement joints
• Crack filler such as Saveto Crack Filler for small repairs before painting

Common mistakes

• Laying membrane on a dusty or damp roof
• Skipping the primer
• Short overlaps between rolls
• Leaving the parapet and drain details for last, or not doing them at all

Get your waterproofing materials in Jeddah

Perfect Steel supplies primers, bitumen membranes, cementitious waterproofing and sealants from our Jeddah warehouse, with delivery across Saudi Arabia. Send your roof area and the products you need on WhatsApp at +966 546 720 678 and we will reply with a quote.