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Ceiling Insulation Options

Written by Safe-R Insulation on .

Ceiling Insulation Options

There are two common types of ceiling insulation: bulk, which fits between or rolls over ceiling joists, and loose-fill, which is blown in or sprayed. Bulk ceiling insulation comes in two types – segments (batts), which fit between the joists above your ceiling, and blanket which is rolled out across the top of the ceiling.

Bulk Ceiling Insulation

Blanket ceiling insulation needs to be installed with no gaps between the blankets or between the insulation and the ceiling. Otherwise the insulation performance will drop due to heat circulating and escaping the insulation. When you’re topping up existing insulation, it can be easier to install blanket insulation than segments.

Segments are installed between joists, so you need to put in higher R-value insulation to make up for the heat that gets lost through the timber. It is important the insulation is well fitted with no gaps, and the r-value is at least 15%-20% higher than required to allow for performance drop via thermal bridging.

Loose-fill ceiling Insulation

Loose-fill insulation is blown onto the ceiling. It is a versatile ceiling insulation option that will suit most situations. It is also a great option if there’s not enough space in your roof to move around and install bulk insulation. Loose-fill should be installed by experienced installer’s using specialised equipment and the correct training.

Minimum R-values (insulation performance) for existing homes

Minimum recommended R-Values for existing homes North Island (excluding Central Plateau) South Island and Central Plateau
Ceilings with no insulation, or up to 70mm of existing insulation  R2.9 blanket or R3.4 segment insulation R3.3 blanket or R4.0 segment insulation
Ceilings with 70-120mm of existing insulation  R1.8 blanket insulation R2.4 blanket insulation

Checklist for choosing ceiling insulation

To get a suitable, effective ceiling insulation product choose one that is:

  • Has a high R-value – R-value is a measurement of the insulation’s effectiveness, the higher the R-value the better
  • The correct width – you need the correct width for the spacing of ceiling joists, roof trusses or rafters, if you’re going to insulate in between – unless using blow-in which suits most situations
  • The correct thickness – to make sure you need to keep at least a 25mm gap between the insulation and the roof underlay
  • Compliant with Standard AS/NZS 4859.1 – so you know the product works as stated. 
  • Correctly Installed – in accordance with NZ standards such as NZS4246:2016

For a free ceiling insulation assessment call our team on 0800 267 992 or contact us here