Expansion Joint Waterproofing for Metal Roofs in Saudi Arabia

Large warehouses and factories are built with expansion joints so the structure can move without cracking. On the roof, that deliberate gap is also a direct route for rain. ETCE waterproofs expansion joints with a flexible EPDM membrane that bridges the gap and moves with it, replacing rigid covers and sealant that eventually tear apart.

Across Saudi ArabiaUp to 15-year warrantyFree roof survey

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ATCO Group – East & West Factory – Dammam

A joint that is meant to move needs a seal that can move

An expansion joint exists because the building will grow and shrink with temperature. In Saudi Arabia that movement is considerable: a metal roof that bakes in the midday sun can cool sharply after dark, particularly inland in Riyadh and Qassim. Where two roof sections meet, or where a new extension joins an older shed, the gap opens and closes every single day. Any rigid seal across it, such as screwed sheet metal covers or thick sealant, is eventually pulled apart.

EPDM suits this detail because it stays flexible and UV-stable for many years, with an average service life of 20+ years. Bonded to sound surfaces on both sides of the joint with Promax Bonding Adhesive, the membrane spans the gap without being stretched tight, so it can take up the daily movement. Once the gap is covered, dust and sand carried by the Shamal can no longer pack into it either.

Symptoms of a leaking expansion joint

A straight line of leaks or stains running across the building
Water appearing where a newer extension meets the original roof
Joint covers with sheared screws or lifted edges
Sealant along the joint that has split down the middle
Sand and debris packed into an open joint gap

How ETCE seals a roof expansion joint

Assess the movementOur engineer inspects the full length of the joint, how the roof sections meet and the state of any existing cover, and documents it in the survey report.
Clear and prepareFailed sealant, debris and loose material are removed so the membrane can bond to firm surfaces on each side of the gap.
Size the membrane1.2 mm EPDM is cut to a width that spans the joint with a generous bonding area on either side.
Bond on both sidesThe membrane is fixed with Promax Bonding Adhesive along both edges and left free over the gap, so the joint can open and close without tearing it.
Check the full runThe completed joint is inspected along its whole length, including ends and changes of direction, and photographed.

Materials & workmanship

Flexible, UV-stable 1.2 mm EPDM membrane
Promax Bonding Adhesive, rated for surface temperatures up to 120 °C
Continuous coverage along the joint, including ends and junctions
Up to 15 years' warranty on EPDM systems and a 24–48 hour after-sales response

Photos from ETCE projects

Expansion Joints - ATCO Group – East & West Factory, Dammam

Expansion Joints - Zamil Group Real Estate, Al Khobar

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

Frequently asked questions

We re-sealed our expansion joint last year and it leaks again. Why?

Sealant and screwed covers are rigid, so the daily opening and closing of the joint eventually splits the sealant or shears the fixings. The answer is not more sealant but a flexible membrane that can accommodate the movement.

Will the membrane stop the joint from doing its job?

No. The EPDM is bonded on each side and bridges the gap, so the two roof sections can still move independently. The joint keeps working as designed; it simply stops letting water through.

Our leak is where a new extension meets the old warehouse. Is that an expansion joint?

Often it behaves like one, because the two structures move differently. Our engineer will confirm this on the free survey and, if needed, treat it with the same flexible detail.

How can we tell if the leak is from the joint or from nearby sheet laps?

Leaks near an expansion joint are easily confused with failing laps or screws. The written survey report includes photos of every failure point, so you can see exactly where water is getting in before any work starts.