- Necessary material
- Rotating or projection window
- What window size for which surface
- Creating the hopper
- Laying of carpentry
- Interest of a rotation at the top
- Interior cladding
- Our selection of roof windows
To be successful, the installation of a roof window must respect certain rules in terms of integration and sealing.
Necessary material• Roof window and sealing accessories
• Roller shutter with solar collector
• Interior cladding
• Expanded polyurethane foam
Cost: about 600 € the window
Time: 1 day
Equipment: chainsaw, ladder, harness, lanyard, meter, saber saw, hammer, screwdriver, screwdriver...
To bring more natural light into one of the rooms upstairs, the owners of this house have chosen to install a PVC roof window. It comes in addition to an existing opening on one of the gables of the house.
Rotating or projection window
It remained to choose a model that is both practical and reliable. There are two systems for opening roof windows.
- The rotational opening, ideal for both high and low pitched roofs (except in the case of very low crawling height), can be done over 180°, which facilitates maintenance of the glazing.
- The projection window finds its place on low slope roofs. The opening is deported outwards: it does not encroach on the living space and leaves the view unobstructed.
In both cases, the lighter must be at least 90 cm. Underneath, there are models with a glass wall that unfolds to form a railing.
On this site, it is a projection model that has been selected (Designo R7 Roto, 1. 134 x H. 98 cm), to keep the entire living space. A motorized rolling shutter with solar collector is integrated.
What window size for which surface
The dimensions of a roof window are chosen according to the surface of the room. The thermic regulation (RT) 2012 provides that the minimum glazed area for a room must be at least 17% of its living space.
You must also take into account the slope of the roof. The more important it is, the lower the height of the window must be.
The majority of manufacturers publish charts with standard dimensions based on these characteristics.
Finally, note that the installation of such a window, modifying the external appearance of a dwelling, implies a prior declaration of work…
Creating the hopper
- After marking the attic, remove the tiles at the location of the hopper.
- Remove from the sides one row more than the window surface, and three rows above and below.
- Remove the insulation.
- Cut the rafters with the chainsaw. The height for the integration of the frame is equal to that of the window + 18 cm (116 cm here).
- After cutting the rafters, unscrew or cut the lines on which are inserted the furs that hold the insulation and drywall.
- Before cutting the battens, install the high and low crosspieces forming the trestle (carpentry support) between the 2 intact rafters (center distance 180 cm).
- Nail them (or screw them) on the end of the cut rafters.
- Materialize the width of the window on the top and bottom rails of the header. This is equal to the width of the window + 8 cm.
- Raise the center distance between the top and bottom rails and cut two rafters.
- Place them in line with the marks already drawn. They form the amounts of the trimmer.
- Cut the battens with a handsaw, taking the amounts as markers. It is possible to use a saber saw equipped with a blade for the wood.
- Check the width.
- Nail the battens to the chevron.
- Solidarize all the parts, they are now part of the structure of the roof.
Laying of carpentry
- Carefully install the frame of the window in its housing.
- Make sure the brackets rest on the top and bottom rails.
- Check the squareness of the frame by checking that its diagonals are strictly equal.
- In case of deformation, it is imperative to correct the position of the amounts and crosspieces of the trimmer.
- Now cut the insulation and the siding from the inside of the housing, using a saber saw equipped with a metal blade (to cut the frame).
Interest of a rotation at the top
The pivoting of the opening is done here at the top, in the upper third of the window, thus providing a opening angle up to 38°. The window is equipped with a standard vapor barrier collar to remove stray air inlets and, optionally, a insulation block to reduce thermal bridges. On this non-motorized model, opening, ventilation and cleaning are easy thanks to a single handle at the bottom.
- Assemble by screwing the elements that constitute the covering of the roof window. They come to hide the rafters and insulation.
- Follow the manufacturer's instructions.
- Record the remaining thickness between the interior facing and the window.
- Draw the cut line inside the cladding without removing the protective film.
- Cut out the walls with a jigsaw.
- Finish cutting in the middle of the room to prevent it from breaking.
- Deburr the corners with sandpaper.
- Screw the fixing brackets supplied with the elements, respecting the recommendations of the manufacturer.
- Position the cladding in its housing.
- Check the accuracy of cuts and junctions between elements.
- Adjust if necessary. The cladding is maintained by the legs that come to rest inside the inner facing (here plasterboard). All spaces will eventually be filled with expansive foam.
- Clip the finishing profiles on the edge of the trim.
- Depending on the quality of the cut-outs, plan to apply a filler and then one or two coats of finishing plaster (before placing the profiles).
- Outside, assemble the roller shutter to the roof window. Depending on the type of sun protection, the laying methods vary considerably.
Our selection of roof windows
Solar. Model equipped with a rotation opening system controlled by a motor powered by a solar battery. For high installation on sloped roofs from 15 to 90°. Sleeping and opening in varnished solid pine. Comes with remote control. GGL Solar, Velux.
Tailored. Pyramidal window for flat roofs. Made from aluminum profiles with thermal break. It is equipped with a hinged frame and leaf, hinged manually or by means of a motorisation. Low emissivity glazing (2 layers of tempered glass 6 mm + argon blade 16 mm). With lighting and exclusively made to measure. GV Pyramid hinged, Glazing Vision.
Convertible. In pine, a system combining a projection roof window (up to 45°) and a lower leaf unfolding vertically to form a balcony. Lateral balustrades unfold automatically when opening and hide in the window in the closed position. Double glazed laminated glass inside and tempered outside. For pitched roof from 35 to 55°. FGH-V P2 Galeria, Fakro.
Ready to ask. Rotating window in Nordic pine. It fits into the roof to prevent heat loss. Simplified implementation thanks to markings and pre-drilling of all holes. Connection accessories sold separately. Available in three heights from 78 to 118 cm and three widths from 78 to 114 cm. Starting from 141 €. "Roof window", Lapeyre.