How to Replace Door Walls With French Doors

Measure the size of the new French doors with a tape measure and compare this to the size of the existing doors in the wall. If the French doors are taller or wider than the existing doors, measure how far out on either side of the existing doors the lintel stretches. Sit a concrete block as long as the French doors are wide, plus the extra lintel width, in front of the door wall.

Clear the area in front of the door wall of any objects other than the concrete block. Build a temporary wall 3 feet back from the door wall. This temporary wall must be as high as the French doors. Chip away the mortar from the brickwork around the existing lintel, using a chisel. Chip away mortar from the brickwork around both ends of the lintel to make space for the extra length of the new lintel.

Remove the bricks from the side of the wall where the mortar has been chipped out to leave a 1 1/2 inch deep notch in the wall where the new lintel will fit. Fasten the king studs to the ends of the beam. Fasten the jack studs onto the beam next to the king studs. These studs are the framing members that will support the weight of the wall through the lintel.

Lift the concrete block that will serve as the new lintel up to the hole where you just removed the bricks. Rest one end of the lintel on the temporary wall. Tap the other end of the lintel into the hole using a mallet. Remove the existing lintel and the rest of the bricks from the wall along the length of the new lintel. Tap the lintel into place in the wall with the mallet.

Remove the brickwork from the wall below the new lintel to clear an area large enough for the French doors to fit. Mix a batch of cement from one part cement, three parts sand and one part water. Tidy up the edges of the hole by inserting new bricks into the gaps and cementing them in place using a trowel. While the cement is setting, remove the temporary wall. Allow 48 hours in total for the cement to set enough to continue.

Unpack the French door unit outside the building. Remove all safety framing and other transit protection from the pieces, such as polystyrene and cardboard covers. Leave any clips that are designed to hold the doors in the correct alignment while they are being fitted, as these are essential to the correct hanging of the door during installation.

Apply a line of caulking beads on the floor where the threshold is to be fitted. Stand the base of the door in the opening in the wall and align the threshold with the hole so the door will stand in the correct position when stood up. Raise the door into position, then adjust the door so it is flush with the walls and floor.

Screw the side jamb, on the side of the French doors that does not open, to the wall using two 3-inch drywall screws. One screw should be positioned 6 inches below the head jamb while the other should be positioned 6 inches above the threshold. Go inside. Inspect the gap along the top and active side of the door. If the gap is wide at the top or side, cut a “shim” or small piece of plywood and tap this into the gap using a mallet.

Check the gaps around the door again to ensure the door is plumb with the walls on both the inside and outside of the building. Tap four shims into the gap down the side of the latch jamb to hold the door in place, one 6 inches from the top of the door frame, one 6 inches below the sill, and one on either side of the lock.

Tap four shims into position down the inactive side of the French door frame. From outside, countersink one 3-inch drywall screw through each shim on the inactive side of the frame. Recheck the door frame to ensure it is still plumb with the walls and floor, adjusting it if it is not.

Fill the gaps between the walls and the door frame with fiberglass insulation. Install the door finish provided with the French door according to the manufacturer's instructions. Install plasterboard or re-plaster around the door as required to repair appearance of the interior wall.