A quick reality check

While not all roof insulations are created equaly, it has to be said that all insulations work, provided the correct thickness is installed. Unfortunately we have seen multiple contractors installing incorrect thicknesses and general poor workmanship displayed. At Fibre-Spec Ceiling Insulation, we want you to understand what R-Value means and the pros and cons of common loose-fill insulations on the market and possible risks associated with various products.


As we specialise in Loose-fill Ceiling Insulation, we have a very good understanding and first hand experience in working with it. Below we will point out some areas of concern when choosing the which loose-fill insulation suits your needs or requirements.


The first and most important factor to consider is weight and specifically the load upon your ceiling. We have unfortunately seen multiple ceiling collapses due to cellulose fibre's density and subsequent heavy weight. The advantage of choosing Thermo-Floc® roof insulation over an alternative loose-fill insulation is weight. In the table below we will compare the two common forms of loose-fill insulation fibreglass against cellulose fibre for a comparison.

Thermo-Floc® (Fibreglass)

Cellulose Fibre










*The weight of the insulation per square meter is calculated according to the average density per cubic meter.

Thermo-floc® 12.5kg per m3

Cellulose fibre 28kg per m3

Majority of ceiling collapses have occured either to a burst geyser or latent (hidden) defect in the roof structure. Once you add weight ontop of a ceiling, this weight is almost always the catalyst for the ceiling collapsing, you just dont know if and when it will happen as it usually occurs without any notice. Unfortunatly from our experience the large majority of ceiling collapses occur with heavier insulation products. For example if a product such as cellulose fibre becomes exessively wet, further damage could result to the interior of the house as the composition of various insulations will either become like paper mache and the powder additives are now liquified and absorb into carpets and bedding and probably need to be replaced.

* See example of Baby Clinic ceiling collapse below


In all our years of insulating, we have yet to see a ceiling collapse caused by dry fibreglass or any light weight insulation that hasnt been exposed to large volumes of water. With cellulose fibre we have seen multiple ceilings collapse even without the introduction of water, simple dry cellulose fibre being too heavy for the ceiling and thus causing them to implode into the interior of homes.


Below are a few examples of entire garages collapsing, living rooms, bedrooms etc.