Environmentally Friendly buildings from Sustainable Timber
Thoma Holz100 – much better than the building codes
When it comes to fire resistance, Thoma Holz100 houses offer full protection without compromise:
Timber will only burn well when it is split thinly and surrounded by air. A Holz100 wall element does not burn well – it merely chars slowly on the surface.
As a result, Holz100 elements achieve sensational fire resistance ratings, all of which are certified by independent certification bodies. After up to 180 minutes exposure to flames and with temperatures between 900 to 1000oC, full load-bearing capacity and integrity were maintained.
Structural collapse due to the expansion of steel reinforcement (as is the case with reinforced concrete floors) is impossible for floors made from Holz100.
The non-exposed surface of a concrete wall exposed to fire can become extremely hot, resulting in a risk of melting electrical cabling. This may in turn set fire to fixtures and fittings within adjacent rooms.
For Holz100 elements exposed to flames for 120 minutes, the temperature of the non-exposed surface will only increased by a maximum 1.8% - Holz100 is a safety shield against heat.
Thus Holz100 elements are up to six times better than the statutory minimum required fire resistance of elements of structure! Not only do they offer greatly improved levels of safety compared with typical timber-frame houses, they also offer greater levels of safety than a comparable concrete floor.
In the case demonstrated, a typical timber-framed wall would have long burnt down. Concrete walls and floors can fracture after only a few minutes. As a result the steel reinforcement bars are exposed and this leads to the dreaded spalling, structural weakness and significant heat transfer to the non-exposed side of the wall or floor.
The extremely good fire resistance ratings of Holz100 elements are due to fact that there are no gaps.
The wooden dowels are also better than nails would be in the event of a fire. Whereas metal nails quickly heat up and loose their strength characteristics, wooden dowels will continue to function even after hours of flame exposure.
The graph shows the rise in temperature at three different measuring points on the cold side of a Holz100™ element (36 cm) during a fire test where the other side was exposed to a 1000°C flame. In similar fire safety tests a common 2x4 wood construction would rapidly burn down completely. The iron in reinforced concrete walls and floors expands when exposed to extreme heat, causing the concrete element to crack and in some cases collapse.
The Holz100™ element will remain almost unchanged as wood is a poor heat carrier. The temperature on the reverse side of the wall has only risen by a few degrees and the carrying layer in the Holz100™ element remains undamaged. The advantage of using wooden dowels is that you achieve fire safety standard R60 - R90.