Can a roof help against earthquake?

You may be surprised by this question; either because you live in a region, where earthquake is not common or because you don’t think roof matters in an earthquake.

Can a roof help against earthquake?

 

New houses with GERARD roof built in After-quke renovation program in Posočje, Slovenia

 

It was a real shock at the end of last year when the media was breaking news about the earthquake in Croatia. Having neighbouring countries like Slovenia, Italy and Hungary nobody would have expected earthquake in Croatia. And yet, on 29th December 2020 the unimaginable happened: an earthquake, in a magnitude 6.4, struck Central-Croatia about 30 miles south-east of the capital Zagreb and could be felt across the Balkans even in Hungary, Serbia and as far away as Italy. It rocked buildings and the aftershock touched regions beyond the Croatian borders causing material damages in a massive area.

 

How can a roof protect your home against a minor earthquake?

If your region is hit by an earthquake and even if you live far away from the epicentre but your house is still being rocked the weakened walls under a heavy roof could even collapse. However, a light roof may offer you some protection even in case of minor earthquakes. How?

- Light weight is of paramount importance: GERARD corrosion resistant steel tile roofs are 6 – 10 times lighter than heavy weight concrete and clay roofs. Weakened walls may be still able to hold a lightweight roof saving lives under it.

- Steel tile roofs provide a strong interlocking membrane that strengthens the building structure. Each tile covers approx. 0.5 sq metres and interlocks with adjacent tiles above, below and on each side. The tiles are nailed to a lattice of timber battens, which are in turn nailed to the rafters.

- GERARD roofing tiles cannot break away from the battens during an earthquake as they are securely fastened in 8 places, eliminating debris that can fall through ceilings or onto areas outside the building.

- GERARD roofs are only installed by roofers world-wide who have been trained to GERARD roofs installation standards to ensure the high performance of the roof.

 

GERARD roofs tested and proven in real earthquakes

The most common cause of damage, injuries and deaths in earthquakes are structural movements in buildings often made worse by heavyweight roofing materials moving and collapsing due to insufficient structural support.

Leight-weight GERARD roofs proved to be secure in such natural disasters and there are several documented cases when standing up to earthquakes for instance in Northridge, California of 6.8 in 1994 and Kobe in 1995 of 7.2 on the Richter scale, saving houses and lives from disasters. The least affected roofs were the stone-coated steel roofing materials like GERARD. Scores of homes with these roofs had no structural or roof damage even though they were located in areas of significant destruction with neighbouring houses with traditional heavy roofs showing serious damage. The much lighter roof weight substantially reduces the strain on the building frame and the interlocking steel membrane enhances the structural integrity enabling the house the stand and hold its roof even with damaged walls.

In number of earthquake cases, roof weight was very likely to have been the significant factor in collapse of the entire structure.

Can a roof help against earthquake?

 

Damaged buildings in Petrinja by the earthquake in Croatia, 2020

 

Furthermore, the Slovenian government established the State Technical Office DTP (Državna tehnična pisarna) which approved GERARD Roofings Systems as the most suitable roofing system in After-quake renovation programe. DTP was etablished only for the restoration of demolished buildings after earthquke 2004 in Slovenia. (See illustrating photo of the restored buildings damaged during the Slovenian earthquake equipped with new GERARD roof) Finally, for new construction there are considerable cost savings by specifying a GERARD light-weight roof because of reduced cost of framing specification and foundations.

Light-weight roofs save you money and might save lives as well.