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Environmental ventilation


Rising damp, excessive moisture, buckled floor boards, mould, and musty odours are all symptoms of excessive moisture in the subfloor, often caused by a lack of ventilation.

The presence of moisture in the crawl space (see site photos below) does not of itself mean that a permanent mechanical ventilation system is required. If the reason for the moisture is preventable and/or caused by an event which is controllable, then a ventilation system may not be necessary. In extreme cases, the subfloor will require stabilising prior to installing a mechanical ventilation system. This is achieved by pumping warm air into the subfloor, installing sub floor dehumidifiers and dehumidifiers in the dwelling as well, in order to dry out the subfloor crawlspace of the property.


Subfloor dryout procedure


1. Moisture detecting

On assessing a site with moisture issues in the subfloor, we will undertake moisture readings tests including taking soil moisture readings using purpose specific moisture detection equipment. In addition to the soil test, we test both the crawl space and the timber floor using non penetrative moisture detecting equipment which isolates and exposes moisture pockets in hard surfaces. We may also use Thermal Imaging cameras (pictured below) which can identify moisture which is not visible to the eye.

2. Dry out and dehumidification

If the moisture underfloor is extreme then we will install our powerful trailer mounted and portable diesel fired heating units (pictured on right) which introduce heated air into the crawlspace, promoting moisture evaporation. The evaporated moisture is then condensed by dehumidifiers and the now liquid moisture is pumped from the immediate area into sewers or drainage points.heaters to evaporate the moisture quickly. Airmovers and dehumidification equipment (pictured right) are also used to reduce the moisture in the crawl space before commencing the installation of a ventilation system (if required) which will stabilise the moisture in the crawl space.


In most instances, adding warm air into the sub floor crawl space will be vital to the long term drying of the under floor area. When combined with cross ventilation, the heated air will assist in the drying process greatly and the success of a salvage operation on a moisture contaminated subfloor and the rescue of building components is determined by time - and heat drying of subfloors is muich quicker than drying with cold air.



Permanent subfloor dryouts via ducted heating

By permanently adding warm air from the ducted heating in the controlled living areas above, combined with cross ventilation, permanent radical changes can be seen in the crawl space. This can be achieved by ducting air into the crawl space from the property above using reverse ducts (as per below) which pulls controlled warm air from the dwelling into the crawl space. This system is only available to some properties that already have existing ducted heating and the subfloor space to install the system.