- You want to insulate your attic at € 1?
- Many architectural constraints for the ITE
- ITE under coating
- 1 Site preparation
- 2 Laying the seat profiles
- 3 Installation of insulation panels
- Some tips for installing an IPE
- 4 Application of the three layers of plaster
- 5 Fastening of facade elements
- Repositioning the downspouts of the gutters
- Reinstatement of shutters
- Info +: fix blinds on the front
Exterior insulation must respect the architectural style of the area. The colors of plaster and exterior joinery are to be chosen according to what exists around to maintain a certain unity.
Cost: about 160 € / m² (insulation + coating + installation)
Time: 6 weeks
Equipment: meter, hammer, cutter, handsaw and circular saws, mason ruler, square, spirit level, trowel, trowel, shears, plaster knives, paint rollers, puncher, drill / driver, grinder, welding machine, mixer, scaffolding, pressure washer...
The new owners of this house, classified E by the DPE (energy performance diagnostic), decided to undertake insulation work to end the electricity bills that could weigh on the budget. By choosing insulation from the outside (ITE), they reduce energy losses while retaining the entire living space.
The ITE can indeed earn up to three rankings to the DPE, which is an asset in case of resale.
You want to insulate your attic at € 1?
Test your eligibility by filling out the form below:
Many architectural constraints for the ITE
In addition, all ITE system manufacturers offer high-performance insulation modules that eliminate thermal bridges during the installation of accessories hung on the façade (shutters, awnings, rainwater downflows, etc.).
The technique of the double wall has automatically been eliminated since the building had too many architectural constraints (Genoise, spoiler, wall already thick).
The homeowners then ruled out the cladding solution and turned to a finishing plaster to maintain the home's regional style.
ITE under coating
The insulation used here is made of expanded polystyrene panels (60 x 120 cm, 15 cm thick) which offers a thermal resistance R = 3.95.
To hold it in place, it is glued to the wall and then mechanically fixed with suitable dowels to ensure better durability. A specific coating, reinforced with a fiberglass frame comes to cover the polystyrene before, after complete drying, a layer of under-coating is applied.
Finally, a primary absorption regulator is rolled to standardize the support and allow the adhesion of the finishing coating: a monolayer coating applied manually. Depending on the desired aspect, it is scraped, smoothed or floated.
1 Site preparation
Install the scaffolding (preferably two) in accordance with the installation instructions to ensure secure work height. Use legs of strength.
Cover the pallets of insulating panels stored on the ground.
Using a pressure washer, wash the facades with clean water.
Using a grinder equipped with a metal cut-off disc, cut off from the wall the fasteners sealed in the masonry (handrails, hinges and stops shutters, grids defense...).
Be sure to wear appropriate protection (gloves and glasses).
2 Laying the seat profiles
At the perforator, make holes spaced every 20 cm to install at the foot of the facade aluminum starting profile.
Get help to maintain the profile during drilling after controlling the plumb with the spirit level.
To abut two starting profiles, use a large mason ruler equipped with a spirit level and proceed with fixing as before.
If during installation of the profile, an obstacle is encountered (here an electric cable), measure its location and then make a notch to the grinder.
When the ground is uneven, draw a line of reference (here 80 cm at the highest point of the ground) which will help to cut and lay the insulating panels on the starting profile.
In the presence of a zinc flashing, pre-pierce it, then slide the tongue of the profile under the flap strip to ensure watertightness.
3 Installation of insulation panels
Prepare the adhesive mortar in a container with a mixer.
Cut the polystyrene panel with a handsaw to the reference line.
Glue the panel (six pads) then the plate to the wall by pressing.
Continue gluing the first row of panels to openings flush with tables, lintels and lighters.
Lay the second row in the same way by staggering the joints in half (stone cut).
Regularly check the planks of the panels; horizontal, vertical and diagonal to the Mason Rule equipped with a spirit level.
Adjust manually as needed for good flatness.
To embed the cables or pipes in the insulation, trace and cut the grooves in the polystyrene using a handsaw.
Some tips for installing an IPE
To make up the difference in thickness between the base and the cladding, cut polystyrene strips (H. 10 cm, thickness 1 cm) to the hot wire machine. Adhere them to the adhesive mortar at the front feet before attaching the aluminum starter profile.
Glue the panel by trowel-bonding the mortar sticks, and then mark the cables or pipes running behind the panel with a pencil to avoid any punctures in these areas.
For a good behavior of the insulation at the corners of the facades, make a harpment of the blocks (placing rows alternately).
During the installation of the panels, create reservations for the subsequent fixing of the shutters.
Apply expansive foam to fill voids.
In the shutter shutters, drill three fixing holes.
Mortar the back of the insulation modules of the future hinges and place them, while sliding the dowels into the holes.
After drying the mortar, screw the modules into the wall and then complete the glued laying with polystyrene cut to size.
Then apply foam expansive to make insulating joints.
Cross the panels at regular intervals, at the studs, with a perforator (concrete drill 25 cm) to drill the front wall.
Insert a large-headed dowel into each of the holes and insert the nails that mechanically fix the insulation against the wall (in addition to the adhesive mortar).
Hit the assembly (peg, nail) with the rubber mallet so that it sinks 2 mm.
4 Application of the three layers of plaster
Prepare the mixer with the mixer. Apply it to the plastic trowel on the polystyrene panels and then unroll in the fresh fabric of glass cloth.
Off coat knife, smooth the undercoat to remove the frame of glass cloth.
Continue laying by overlapping the 10 cm strips.
After drying, position the screen angles at the openings, corners and at the top of the wall.
Continue the application of the second pass of under-plaster on all facades.
Smooth carefully with the broad coating knife to perfect the angles and prepare the installation of the finishing coating.
After 24 hours of drying, apply to the roll and brush on all coated surfaces, a primer to make the bottom uniform and to prepare the adhesion of the finishing coat.
Prepare the finishing coat with a mixer until a homogeneous mixture is obtained.
Incorporate the necessary amount of pigment to obtain the desired shade.
Apply plaster to a trowel before applying it over the entire surface to achieve an even layer 3 mm thick.
Before drying, pass a plastic trowel making circular movements to obtain the desired appearance.
Clean the trowel regularly.
5 Fastening of facade elements
Seal with sealant an aluminum edge strip over the thickness of the insulation.
Then, fix this edge strip mechanically to the masonry.
Using the grinder, cut out the cement strips and stick them to the mortar on each existing window sill.
Make the gaskets with putty.
Place the new brackets on the railings.
Then screw the guardrails into the masonry (through the insulation) with bolts pegged.
Carry out scrapped formwork to complete and make up the thresholds at the level of each French window set back from the insulation.
Protect with masking tape, pour concrete, then smooth with a trowel.
Repositioning the downspouts of the gutters
Drill with a hole saw the location of the bindings of the descent.
Mortar the fixing modules, then fix them with the screws of the clamps.
Connect the descent to the gutter.
Reinstatement of shutters
Pre-drill a hole in the metal drill bit in each insulation block.
Perform the threading of the hinge with a specific drill bit.
Screw the hinges, then install the shutters.
Info +: fix blinds on the front
Fasteners on ITE must pass through the insulation to find masonry supports.
Fischer, for example, has developed the Thermax system for fixing awnings.
It consists of a threaded rod (sealed with a chemical anchor) and a head acting as a conical thermal bridge switch on which are fixed the legs that support the blind.
• Expanded polystyrene panels (Knauf Therm TH38 SE, 60 x 120 cm, 15 cm thick)
• Aluminum starting profile
• Frame made of glass
• Angle corner corners
• Single layer plaster
• Cement mortar
• Ready-mixed concrete
• Expandable foam cartridges
• Masking tape
• Various anchors and fixings