- Well delimit the opening
- Lintel: several choices...
- 1 Realization of the lintel
- 2 Opening the wall
- 3 Installation of the door block and finishes
The opening made in the wall allows here to connect the house and its extension. It requires the implementation of a lintel reinforced concrete to install a door block.
Cost: about 130 € (including the door,
excluding hiring jack hammer 80 € / day)
Time: 3 days (excluding drying time
Equipment: ruler, spirit level, cattail,
flat chisel, handsaw, trough, tongue
cat, hammer chisel and pointerolle SDS,
Screwdriver, chainsaw and disc
diamond Ø 230 mm, jackhammer...
The passage created here connects an existing living room to a future office whose floor is 80 cm lower. The opening is accompanied by the installation of a door block and an industrial staircase recovered and adapted to compensate for the difference in level (see "Do it yourself", System D # 802, November 2012).
Well delimit the opening
The location of the opening is first measured in the living room. It is the dimensions of the door block (here 92 x 208.5 cm for a door of 83 x 204 cm) which condition those of the gap. By adding about 4 cm around the edge (fitting and sealing), the opening to be made is 100 x 212.5 cm. Once these measurements are reported on the wall to be opened, all you have to do is drill the wall at the four corners with a suitable drill bit. The four holes are then joined by a trace in the felt. Singular point of this project, the lack of shoring. The house is relatively recent: the floor rests on a floor slab with peripheral chaining. It was therefore possible to pierce the opening without risking a collapse of the wall. Especially since the lintel only spans about twenty centimeters on either side of the door.
Learn more about this theme?
Find a special file in System D n° 858 (July 2017)
Check it out
Lintel: several choices...
As the wall portion above the opening is stable enough not to be supported, the lintel construction has been simplified. The choice of reinforced concrete is explained by the ease of implementation. But other techniques exist. For example, an IPN ("I" metal beam) sealed on either side of the opening or a prefabricated concrete lintel. Moreover, the wall being doubled on one side with an insulating complex (plasterboard + 5 cm of polystyrene), the reservation was made only on one side: the blocks were indeed dug only on the half of their thickness.
1 Realization of the lintel
After delimiting the location of the opening on the living room side and reporting the measurements on the extension side, draw the outline of the lintel and passage with a ruler and a level.
Cut out the outline of the lintel by firmly holding the chain saw (diamond disc Ø 230 mm). Wear glasses and a dust mask.
Dig with a chisel the reservation for the lintel, without crossing the wall (mallet and chisel are less effective). The breeze block wall (left intact) can be used as formwork.
Prepare the reinforcement to be incorporated (4 Ø 6 mm round bars with 10 x 10 cm stirrups).
Place a shuttering board at the bottom of the reservation and slide the reinforcement. You may have to deform it to get it into the cavity.
Wet the hole with a garden sprayer and then trowel it with concrete (one bag of 35 kg cement, five buckets of sand, seven chippings and two of water).
Then screw the front face of the formwork keeping access for filling (if necessary, break a little more wall).
Plant pegs if necessary.
Pour the concrete, with a bucket, through the access practiced. Stir with a stick, move the reinforcement, then vibrate the concrete. Let dry.
When pouring concrete to make a lintel, it must be vibrated to chase the air and ensure a good coating of gravel. For this, tap the front of the formwork at the cattail for a long time. The water drains, the concrete settles and becomes homogeneous.
2 Opening the wall
With a chain saw equipped with a diamond disc, cut the amounts of the passage following the lines. Then dig with a chisel.
After cutting the sides of the opening with a chainsaw, tear down the wall. Renting a professional jack hammer is essential here.
When all the masonry is removed, there remains the insulation complex to be deposited (plasterboard + 5 cm of polystyrene). Cut it with a special handsaw for plasterboard.
The panel separated from the wall on each side is retained only by its base. It is enough to press on it so that it falls back into the extension. Rectify if necessary around and remove rubble.
3 Installation of the door block and finishes
Present the block equipped with its door of 83 x 204 cm. Do not remove the shims between the door and its frame: they will be used to adjust the joinery.
Elbow the tabs on the door block. Fix them to the desired length by a screw in the rabbet around the frame: 2 lugs per upright, 1 in the middle under the lintel.
Place the level on an upright to control the verticality of the doorframe relative to the wall plane and inside the opening.
Fold the legs in the hollow of the blocks. Seal them with mortar pressed with a trowel. On the living side, close the seal on the edge of the block with plaster tile adhesive.
The doorway is completely covered with plasterboard scrap (BA13)
Apply joint strips to all the junctions and the armed band in the corners. Coat them in two passes by squeezing the tape with a wide dressing knife.
• Door block with overlay door
83 x 204 cm (available in GSB)
• Cement (1 bag of 35 kg), sand, chippings
• 4 round irons Ø 6 mm, stirrups 10 x 10 cm
• 1 plasterboard or BA13 falls
• Formwork boards
• 5 brackets, galvanized steel screws
• Adhesives for drywall, plasterboard
• Finishing plaster
• Roll of seal paper tape + special glue
Watch out for the opening!It is advisable to opt for a door model that harmonizes with existing joinery. Attention also to the sense of openness. When you open a door by pulling it towards you, it is a pulling: "left" when the lock and the handle are on the left; "Right" when these are on the right. When you have to push the door to open it (our yard), the opening direction is called pushing right or left.