Rust Treatment for Metal Roof Sheets and Sandwich Panels

Why encapsulation works where paint keeps failing

Rust needs oxygen and moisture to keep spreading. On the coast at Dammam, Al Khobar and Jubail the air supplies both, together with salt that speeds the reaction up. Inland around Riyadh the trigger is different: fine dust and silica settle into laps and hold moisture after rain or morning dew. Either way, a rusted sheet left exposed loses a little more thickness every season.

Paints and bitumen-based coatings struggle on Saudi roofs because the sheet surface in summer runs far hotter than the air. They harden, crack and let water creep back underneath, where it is trapped against the steel. EPDM stays flexible and UV-stable, and the Promax Bonding Adhesive that holds it down is rated for surface temperatures up to 120 °C, so the seal copes with the heat. With the membrane bonded over prepared metal, the corroded area no longer touches sand, silica or humid air, and the oxidation stops.

Signs your roof sheets need rust treatment

• Orange or brown staining around screw heads and along side and end laps
• Blistered or flaking paint at cut edges, ridges and gutter lines
• Rust streaks on the underside of sheets, visible from inside the building
• Pinholes that show daylight or drip after rain
• Corroded top skins on sandwich panels, especially near the coast
• Earlier paint repairs that have cracked and started to peel

How we treat rusted roof sheets

1. Free survey and mappingAn engineer walks the roof, marks every rusted sheet and area, and sends a written report with photos and an itemised quotation.
2. Treat or replace decisionSheets that are still sound are scheduled for treatment, while any that have rusted right through are listed separately so you only replace what cannot be saved.
3. Surface preparationLoose rust, dust and failed coating are removed and the metal is cleaned, giving the adhesive a sound, dry surface.
4. EPDM encapsulation1.2 mm EPDM is cut to width and bonded with Promax Bonding Adhesive over the affected sheets, laps and fasteners to form one continuous barrier.
5. Zone-by-zone handoverThe crew moves across the roof one zone at a time so production and storage below carry on, checking each zone before moving to the next.

Materials & workmanship

• 1.2 mm EPDM membrane, flexible and UV-stable, with an average service life of 20+ years
• Promax Bonding Adhesive rated for roof surface temperatures up to 120 °C
• Suitable for single-skin sheets, double-skin sheets and sandwich panels
• Up to 15 years warranty on the EPDM system, with after-sales response in 24 to 48 hours

Photos from ETCE projects

Site photos from ETCE projects in Saudi Arabia and Bahrain. Tap to enlarge.

Frequently asked questions