of venting the area beneath a timber floor is to prevent the
incidence of wood rot and consequential odour arising from high
humidity levels caused by lack of sufficient ventilation as
may be required, to remove moisture gain.
to remember that all space needs to breathe (ventilate) The
space under a timber floor is one such area, however it should
be noted that a vented sub floor area will always be cooler
as a consequence.
barrier can be employed to partially address this problem however
the necessity to vent the area will always be required.
the most desirable form of aspiration or venting of an area
is a natural one, where thermal and pressure differentials about
the building perform the task of ventilating the area as is
ventilation is often referred to as 'passive' by those wanting
to sell you a powered 'positive' ventilation solution inferring
that passive is equal to submissive and therefore not as effective.
eating and there's overeating....and as with anything overdone
there are always unpleasant consequences
open the sub floor area is, then obviously the more efficient
the ventilation, however there is a level to which sufficient
ventilation is considered appropriate and going beyond that
point can often lead to adverse results. The more the better
attitude regarding sub floor ventilation, or any form of ventilation
in fact, is not a wise one.
cases the sub floor area is going to be difficult to assess
due to inaccessibility and this is where you may find yourself
at the greatest disadvantage because the assessment of the problem
may simply be the result of conjecture and supposition.
tell tale signs of certain conditions arising from poor ventilation
being obvious to someone who is experienced in these matters.
You will not know, so it is important that the assessment be
presented to you in writing, so that if you need to get or want
a second opinion you are not trying to think of what was said
When a sub
floor venting problem presents itself it is imperative that
the prevailing dynamics causing the lack of appropriate ventilation
be understood before any solution is proposed or implemented.
In any efficient
natural venting solution there are ingress and egress points
as may be required to facilitate a balanced displacement of
air in the area.
ventilation professional will never proposed a fan be used from
the outset, as a ventilation fan can never be considered a solution.
It can be a refinement to a venting solution but never the solution
in and of itself.
a fan need be employed it should be momentary, and not constant,
so as so create an artificial high / low pressure in the void
If the problem
is caused by poor water drainage, as are most, then the obvious
solution is addressing the drainage, not putting in a so called
'turbo vent fan' as a band aid. This product fail, and require
continual replacement, due to moisture degradation .
outcome being the salesperson's got the money and you're still
stuck with the problem....'Oh yeah but',....
'we tried', ....'wait
'til next season and see how it
goes'....'give it a chance to dry
out', .......doesn't quite do it.
is something that is purchased and employed where a problem
arises out of poor building design and no means of rectification
The so called
solar, or packaged products, require careful consideration as
their performance efficiency and work life needs to be questioned.
A packaged product is one that is sold and claimed to be suited
to all situations.
It is not
a solution designed specifically for your situation and becaomes
a little like buying a pair of shoes and being confronted with
cutting a little off the toes, or filling the toes of the shoes.
useful up to a point but there is no guarantee....just opinion,
and are you going to spend money based on this 'free' opinion.
Forums are good in the sense that they are able to provide alternative
approaches that can be considered whereas they may not have
are used for assisting in the venting of such areas you have
a choice of 'negative' or 'positive' modes
venting is where the fan is employed in a exhaust duty in drawing
the air volume out of the sub floor area and the supply is via
fixed vents of various size to position are used for ingress.
venting is where a fan is used to fill the sub floor area and
discharge occurs with the same size to location fixed vents.
the fixed vents should be of stainless steel irrespective of
other more specialized venting themes one can use depending
on the circumstances and nature of the building along with the
solution not giving rise to other problems.