Ceiling Insulation Systems

Terra Lana Proprietary Double Layer System


We always recommend our proprietary double layer system over a single layer.  Using two thinner layers of insulation instead of one thicker layer gives complete ceiling coverage, as well as the eliminating gaps. Our double layer system will always out perform a single layer of the same R-Value.


Segment System


Thicker R Value segments are in inserted between ceiling rafters. This ensures the possibility of air movement is minimised as the insulation segments completely fill the voids.  Insulation will not fully cover the narrow edges.

Blanket System

Topup layer

Thicker R Value insulation is rolled out across over the top of ceiling rafters, where existing insulation is already present between rafters, or other factors don't permit insulation to be placed between rafters.

Excellent coverage, including rafters, is easily attained. However, the insulation will not reach to the narrow edges and care must be taken to ensure gaps are not opened as this could lead to air movement in any cavities underneath.

Terra Lana Skillion Single layer

Skillion Roof Standard System

Precut blanket folds are fitted between rafters.

Our skillion roof blanket insulation is available in a 570mm wide fold to fit rafters at 600mm centres. Folds are supplied in 2.6m lengths and range from 3-6 folds per bale. Custom widths can be manufactured on request.

Skillion ceiling cavities can have a higher risk of condensation occurring (Branz Bulletin 610). Terra Lana insulation is hygroscopic (can absorb and release vapour) so can help to mitigate condensation risks.

  • Terra Lana is usually fitted from below before the ceiling lining is in place. In this instance, make sure it is well supported with staples and battens or strapping.
  • Terra Lana can also be fitted from above before roof underlay and roofing material is added.
  • Pre-cut widths ensure a snug fit. Where there are no battens or ceiling joists, Terra Lana can be stapled directly to the rafters.
  • A 25mm gap is maintained between Terra Lana and the roof underlay or roofing material.


Terra Lana Skillion Double layer Mento

High-Performance Double Layer Skillion System

Skillion ceilings are often challenging for an architect to specify the right insulation to ensure maximum performance.

Terra Lana has developed this double layer system to ensure no compromises within the thermal envelope. The secondary layer between the ceiling battens creates a thermal break underneath the rafters and ensures the highest thermal performance from the insulation products specified.

Products used in system

When to use this system

  • When you have limited insulation space due to rafter depth.
  • When wanting to reduce thermal bridging through the rafters and mitigate small gaps in the top layer by the perpendicular layer underneath.
  • When wanting to maximise R-Values
  • When using Pro Clima Intello airtightness layers in high-performance buildings

Benefits of the system

  • High thermal performance
  • Reduces thermal bridging
  • Insulating a cavity that is already there

For further technical assistance contact:

Brad Stuart National Specification Manager
M 022 618 9015
E brad.s@terralana.co.nz