Indy Total Construction

Having set the new lintel in place and re-finished the brickwork of the inner leaf above it, you can cut out the brickwork at the sides of the opening and, if necessary, across the base. First, draw the outline of the new opening on both sides of the wall, making it about lin wider and deeper than the actual frame dimensions to give a fitting tolerance.

External walls comprise two layers of bricks; each layer should be treated separately, working in from each side of the wall.

If the wall is a solid one produce a square edge along the opening outline on the inner layer by cutting through bricks where necessary. Always remove complete bricks even if they project beyond the outline. This gives a toothed effect to the edge.

If the base outline runs through the center of a course of bricks, remove the course completely; you can make up the difference later.

Replace the outer layer at the sides of the opening by mortaring cut bricks into the toothed sections so that their cut ends are innermost.

Next, replace the area of wall above the window, laying the bricks on the lintel and copying the original brickwork bond for strength and appearance. In a solid wall, you can create a curved, self-supporting soldier arch by setting a wooden framework in the opening on which the bricks of the arch are laid. Then the surrounding courses are fitted round the arch and the mortar left to set for a couple of days before removal of the formwork.

The frame must sit squarely in the opening; if it is twisted, you may have problems in opening and closing the window and the glass will be under stress and may shatter at the slightest vibration.

In a solid wall you can set the frame: flush with the outer face with its sill overhanging the edge; in the center of the opening with narrow reveals on each side; or flush with the inner face with a sub-sill at the bottom to throw water clear of the wall.

When the frame is set forward in the opening, the sides and top of the reveal are plastered and a wooden or tiled window board set across the bottom. When set at the back, it is normal to trim around the inside of the frame with molding

The simplest method of securing the frame is with frame fixings, a hefty screw and long plastic wall plug, but you can also use conventional wallplugs and screws, wooden wedges or metal frame ties. With each type, wedge the frame in the opening with wood offcuts so that it is set squarely in place, while the fixings are marked and made.

With screws and plugs, clearance holes must first be drilled in the frame and the hole positions on the wall marked through these. The holes are drilled and plugged and the frame fitted.

Wooden wedges are tapped into slots cut in the mortar joints and the frame nailed to the wedges. Metal frame ties also fit into slots in the joints, being screwed to the frame and mortared in place.

In all cases, you must leave a’/sin gap between the top of the frame and the underside of the lintel to allow for any settlement of the structure.

Leave the packing pieces in place. and fill the gaps at the sides with mortar, leaving it about 1/sin below the level of the frame face. Fill this gap with caulk when the mortar has set. Use caulking to fill the gap between the lintel and frame also. If there is a gap below the frame, fill this with bricks and mortar, splitting the bricks lengthways if necessary.

Make a sub-sill from wood screwed or nailed in place, or a double layer of tiles set on a sloping bed of mortar.

Another way is to cast a concrete sill in situ, making up a wooden formwork “tray” nailed to the wall. The sill should overlap the edge of the bricks by no more than in and you can form a drip channel (to prevent rainwater trickling under the sill) along the bottom edge by pinning a length of waxed cord (sash window cord will do) in the bottom of_ the tray. The top of the lintel should slope downwards so angle the sides for this. Also provide reinforcement by setting steel rods in holes drilled in the brickwork.

Mix the concrete from 4 parts sand: 1 part cement and pour it into the form. Agitate the mix to compact it and remove air bubbles and draw it off level with the top of the form. Leave the concrete for at least 24 hours before removing the foiinwork.

The frame fixing is much simpler to use and is ideal for securing wooden members to masonry. It comprises a hefty screw and a long plastic wallplug.

To use, wedge the frame in its opening and drill holes for the fixings right through it and into the wall. Without removing the frame, tap the plug and screw combination through the frame and into the wall, finally tightening the screw for a secure fixing.

Frame fixings are supplied in various lengths to hold wood thicknesses up to 33/sin. Another development of this is the hammer fixing, which is used in the same way, but set by driving a ridged, countersunk pin into the expanding plug.

With the wall above the window opening supported by stout wooden needles and adjustable jacks, and the old window frame taken out you can remove the old lintel and brickwork from above the opening.

Remove the bricks from the outer layer first. These may be laid in horizontal courses across the lintel or they may be set vertically. If the house is old, they may form a self-supporting segmental arch.

Cut through the mortar joints with a bricklayer’s chisel to remove the bricks, making a gradually tapering, stepped opening up to the level of the wooden needle above. This will prevent any brickwork from falling while working on the opening.

Removing the bricks from the outer leaf of the wall will expose the face of the load bearing lintel set in the inner leaf. You should remove this next.

From inside the house, hack off the plaster above the window opening to expose the inner face of the lintel and the brickwork above it. Again, cut out the bricks to foam a stepped opening up to the level of the needle. Then cut into the mortar joints at each end of the lintel, working along the top, ends and underneath. Use a stout bar to lever the ends of the lintel upwards to finally release them. Then get some help to lift the lintel from its bearings in the wall.

the thickness of the wall. It may lodge and form a bridge for moisture to cross from the outer skin to the inner and cause damp patches on the inner wall.

Measure up the new lintel and draw its outline on the inside of the wall centered over the new window position. Remember, the new lintel should be at least 6in wider at each side of the window opening to provide decent-sized bearings. Also, allow an extra lin at each end and on the depth to provide enough space to manoeuvre the lintel into position.

Cut straight down through the plaster along the outline with the bricklayer’s chisel to provide a cutting guide and then hack off the plaster within the outline.

Go on to remove the bricks exposed by the removal of the plaster, again cutting through the mortar joints in an effort to keep as many bricks in one piece as possible. Clean up the bearing openings and make sure their surfaces are flat and level.

Whether you are using a steel or concrete lintel, you will need some help to lift it into place.

Trowel a layer of mortar onto each bearing and lift the lintel into place, setting it centrally over the opening. Check that the lintel is flush with the inner face and outer layer of the wall.

Hold a level against the underside of the lintel and check that it is horizontal. If necessary, correct this by packing pieces of tile or slate beneath the ends. When level, fill the gaps round the ends of the lintel with more mortar and brick offcuts, pointing the joints neatly flush with the surrounding brickwork.