Header tank not seismically braced or strapped

Causes

No restraining straps

Corroded fixings and/or straps

Listed under: metal, plumbing, earthquakes, Roof, durability, corrosion, rust, fixings and hardware

Cause

No restraining straps

Repair

  • install 25 x 1 mm/25 x 0.70 mm or similar stainless steel restraining straps, fixing the tank to roof framing to prevent it overturning or falling off the roof in an earthquake. Use 2 straps for cylinders of up to 200 litre capacity (and a third strap in the centre for larger tanks). The top and bottom straps should be no more than 100 mm from the ends of the cylinder. Some hardware stores have ready-made kits that include stainless steel straps, screws and tensioning devices. At least one kit has a BRANZ Appraisal

  • ensure the support platform that the header tank sits on is also well braced or tied into the roof structure – screw fix one diagonal 90 x 18 mm to each side of the platform if there are no braces. (Where close to a truss or rafter, the platform may be tied back to it.)

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Cause

Corroded fixings and/or straps

Repair

  • replace corroded fixings and/or straps with stainless steel fixings/straps to prevent the tank overturning or falling in an earthquake. Use 2 straps for cylinders of up to 200 litre capacity (and a third strap in the centre for larger tanks). The top and bottom straps should be no more than 100 mm from the ends of the cylinder. Some hardware stores have ready-made kits that include stainless steel straps, screws and tensioning devices

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