Data Sheet:
External Wall Insulation - Flexible Solution Data Sheet
- Information suitable for:
- Retrofit
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Technical information
To achieve a good external wall U-value affix 110mm External Wall Insulation (EWI) Slab to the external face of the walls using suitable fixings 155mm long through mesh, typically using 9 fixings per m², depending on the substrate. Around reveals, sills and heads, affix 30mm Kingspan K5 insulation behind the mesh and continue render around to meet window and door frames - this will avoid any potential thermal bridges. Apply render to the mesh and insulation in 2 coats.
Flexible insulation should continue down to DPC level, with the DPC being extended underneath the insulation. From DPC level to 200mm below the top of the internal floor insulation use 50mm Polyfoam High Impact insulation which has a calcium silicate layer which can be decorated directly.
Ensure insulation within roof space continues through the eaves to meet the top of the external wall insulation forming a complete wrap of the house.
Ensure any air bricks or mechanical ventilation is carried forward through the new insulation and any new ventilation required to meet current Building Regulations.
To achieve a good external wall U-value affix 110mm External Wall Insulation (EWI) Slab to the external face of the walls using suitable fixings 155mm long through mesh, typically using 9 fixings per m², depending on the substrate. Around reveals, sills and heads, affix 30mm Kingspan K5 insulation behind the mesh and continue render around to meet window and door frames - this will avoid any potential thermal bridges. Apply render to the mesh and insulation in 2 coats.
Flexible insulation should continue down to DPC level, with the DPC being extended underneath the insulation. From DPC level to 200mm below the top of the internal floor insulation use 50mm Polyfoam High Impact insulation which has a calcium silicate layer which can be decorated directly.
Ensure insulation within roof space continues through the eaves to meet the top of the external wall insulation forming a complete wrap of the house.
Ensure any air bricks or mechanical ventilation is carried forward through the new insulation and any new ventilation required to meet current Building Regulations.
Hints and Tips
Contact your local planning office and find out if planning permission is required before work is carried out.
A full survey must be undertaken to asses if this method is viable to insulate the external walls as if there is a cavity present then other systems will have to be used.
All work should be undertaken by an accredited installer.
After the insulation is installed it will be very difficult to replace the windows. Therefore it is important to ensure the windows are in a good condition and are replaced or repaired before insulation is installed.
Around window openings cut insulation at an angle to allow as much light as possible to enter the rooms.
Remove all loose and flaking materials from the wall, making all hollow areas smooth, stable substrate.
When walls are retrofitted with insulation it is just as important for the insulation in the loft to be up to date, otherwise condensation may form on cold ceiling areas.
Ensure all joints are butted together with no gaps.