Civil Engineering Reference
In-Depth Information
3
Floors and foundations
Timber versus concrete floors
Concrete floors have long been heralded as the best option for controlling heat loss and
gain in domestic buildings, however I have serious reservations about it. I have never
heard anyone speak against the thermal benefits of a concrete floor so I guess I am
stepping out on my own by raising the next issue for your consideration.
I would be interested to see a study done into the embodied energy of a concrete slab
versus the savings of energy through passive solar heating as a consequence of having a
concrete floor. It would also be interesting to establish whether the mass of earthen
rendered internal straw bale walls are sufficient to compensate for, if not neutralise the
loss of thermal mass as a consequence of building with an insulated timber floor rather
than a concrete one.
Consider the real cost
It is important to consider the real cost of a concrete floor compared to a timber floor.
I was
recently contacted by one of my owner-builders who was looking to reduce the cost of
her new home. She was quoted around $20,000 (2005) for the concrete slab, whereas a
timber floor with insulation would cost less than $5000. One of the primary reasons
people owner-build is to save money so that they can be financially independent sooner,
which will enable them to reduce their work hours. A saving of $15,000 on the cost of a
home has long-term consequences. As most new homes have some finance on them, it is
a $15,000 reduction of debt, plus the interest added to this. The total savings on reducing
your initial loan by $15,000 will equate to a much earlier reduction of working hours.
Every day you don't work is another day that you don't have to use your fossil-fuel vehicle
pumping out its pollutants and destroying our ozone layer to go to and from work. If all
this were taken into consideration, I doubt that a concrete slab would be heralded in such
high regard.
