The Content Of The Article:

Thanks to flake products, attics can be perfectly isolated. Blown with a carding machine, these flakes are deposited in a thick and uniform layer.

attic insulation with blown wool

Necessary material

  • combination
  • mask
  • glasses
  • protective gloves
  • hammer
  • screwdriver
  • cutter
  • blow machine (KI Breath or Exp'Air)
  • adjusting rods
  • masking adhesive
  • flake insulation
  • falls of cleats
  • TF agglo screw (to raise the junction boxes)

Difficulty: 2/4
Cost: from 15 to 20 € / m2 (excluding machine rental)
Time: 4 to 5 hours for 50 m2

Site preparation to insulate attics

suspend the extraction ducts

  • Locate the VMC sheaths and suction port locations.
  • Separate the ducts from the extraction unit, block them with adhesive and hang them at the farmhouses.

nail the false ceiling plates

  • Provide a peg at each end of the attic and two at mid-length.
  • Place them on the false ceiling plates and nail them in the entrances of the farmhouses.

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Information for DIYers

blowing machine

  • The blower must match the type of insulation.
  • In the case of the product implemented here, it can be rented from the trade (KI Souffle card) or loaned (Exp'Air carder) by the GSB according to the number of bags purchased.

brew the wool

  • Pour the flakes into the machine tray.
  • Stir the wool to prevent him from staying in "packs".
  • Adjust the machine to obtain an average density of 12 kg / m3.

insert the air duct into the hatch

  • Connect the blower duct to the fan and pass it through the access door to the attic.
  • Gather the excess sheath at the foot of the hatch.

Blowing of the insulation

start blowing wool in the attic

  • Ask the person next to the machine (to power it regularly) to start it.
  • Start blowing away from the access and closer to the ramp.

fill the attic with wool

  • Perform back and forth to fill the gaps between the trusses.
  • As soon as the thickness reaches approximately 10 cm, stop the blowing in order to replace the sheaths of the VMC.

raise the level of wool in the attic

  • Continue blowing until you reach the required level everywhere.
  • As the level rises, be careful not to stand next to the lines.

Practical tip for DIYers

avoid contact of light with glass wool

Even if Thermo Loft glass wool is incombustible, it is best to avoid direct contact with the recessed lighting in the false ceiling of the lower floor. In this case, two solutions: either we create a separate volume (plenum), or we put hoods of firewalls meeting the French and European standards.

Isolate yourself from lost roofs

Can one isolate oneself the floor of the lost attic of a house on one level?
Christian Pessey's answer:
If the floor of these attics is not already isolated, it can be done perfectly with mineral wool or vegetable (hemp or cellulose), in bulk (flakes). You can rent the device to blow a layer of about thirty centimeters (or more) of insulation.


Video Instruction: The Right Way to Insulate Attics with Blown-in Insulation