What does R-Value mean?
The thermal resistance rating or R-Value is the measure used to determine a material’s ability to resist the transfer of heat. The higher the R-Value the better thermal resistance the product will provide. Around 14% of heat is typically lost through the floor and therefore energy efficiency requirements are set out in the Building Code to ensure New Zealand homes meet the minimum R-Value rating – especially in colder climate areas.
How can QPOD™ improve the R-Value of my proposed house?
Apart from QPOD™ being the sustainable choice and manufactured with 100% recycled plastic, it’s proven that raft slabs (on top of the ground) are stronger than conventional ‘in ground’ slabs and achieves higher insulation with the 220mm encapsulated air thermal break underfoot, making for a cosy home during the winter months.
Would edge insulation make a difference to the R-Value?
Yes, for sure! Most heat escapes from the edges so by adding perimeter edge insulation the R-Value rate can increase your R Value performance 2 – 3 times, depending on the area to perimeter ratio and insulation system you choose.
The QuickSet system is a fully insulated formwork system providing options for different levels of insulation and side wall design. QuickSet’s pre-finished insulated side wall panel and full blanket ground insulation provides a fully thermally broken slab. The formwork or side wall is pre-finished in grey (meaning no plastering required) and has a protective wrap to be removed before building is finished.
Nationwide QuickSet is installed by licensed foundation installation teams with years of experience and 100’s of raft installs under their belt. So, whether it be underflooring heating, split level, block work or a simple QuickSet raft foundation, they take care of the install, pour and saw cuts.
Is there a way to calculate what R-Value I could expect for my foundation?
QPOD™ have made it easy to calculate the R- Value of your foundation design, try our online free calculation tool. This also provides estimated steel and concrete requirements when using the QPOD™ Raft Foundation System including toggle options for different Quickset Insulation systems.
How do we get our Data?
QPOD has engaged green building council specialists for an independent review, we have modelled all the QPOD and Quickset insulation system options.
The slab and edge heat losses are calculated per ISO13370:2007 with slab edge calculations per ISO10211:2007. Performing the calculation or modelling that way results in an R-value for the entire floor system including the edge losses so the results is then directly applicable for Building Code compliance when using the NZS 4218:2009 schedule method.
Components of the system calculated
3D model of Qpod system used to determine the equivalent thermal conductivity. This is then used along with the insulation layer below the slab to calculate the construction R-value. The construction value is then used in the ISO13370:2007 calculation, along with the 2D slab edge PSI value in accordance with ISO10211:2007, to calculate the overall floor system steady-state R-value.