Section 6.1.7
Insulation
Insulation is required in cavities to ensure the property meets the Building Regulations and TER of the property.
Retrospective insulation is the Knauf ‘Supafill 34’
For retrospective (retro fill) insulation where gas membranes are not installed, cavities must remain clear to allow the insulation to cascade down below DPC.
Where a gas membrane is installed, the cavities must be insulated below the gas membrane.
Before retro fill works can take place on site, the machinery needs to be calibrated and tested.
To place retro fill insulation into the cavities, holes must be drilled into the external walls from inside the property.
Designed drill patterns must be followed.
Insulation to be placed as per the design.
Once insulation has been completed, the drilled holes must be pointed up using mortar.
In areas of very severe wind exposure (shaded pink), partial cavity insulation should be provided within the cavity.
Note - Full fill insulation would not conform to NHBC Requirements in areas of very severe exposure.
Partial fill insulation should be fitted tightly against the internal leaf using retaining devices.
Wall ties should be set 450mm vertically and 600mm horizontally.
Insulation should be tightly abutting each insulation board and cavity closures.
Insulation should be neatly cut at corners and bends to ensure that the thermal performance is continuous.
Insulation should be neatly cut around lintels to ensure the risks of cold bridging are eliminated.
Where you have a tie, a small cut with a saw should be applied to ensure no gapping appears in the insulation.
