Lintel Failure Repair in 10 Easy Steps
Problems with lintels usually manifest themselves as diagonal cracks or step cracking in the masonry above doors and windows. Such cracking should be immediately investigated and a remedial plan subsequently developed; failing to address the problem allows it to develop further, leading to costly, intrusive and time-consuming repairs becoming necessary.
Brick lintels may be in the form of a traditional curved arch or of a straight flat arch. Both types masonry arch lintel utilise the compressive strength of the brickwork transfer vertical loads, horizontally to the brick abutments on either side of the opening. Oftentimes the underside of the lintel is fortuitously supported by wooden or steel window frames. When these frames are removed and replaced with UPVC units the contribution to the support is lost, causing the lintel to sag and the brickwork to crack.
Where window lintels and arches have failed, simply repairing the damage without reinforcing the brickwork can prove futile. By introducing high tensile stainless steel bars into the masonry above the opening it is possible to convert the brickwork itself into a load-carrying beam. This can be achieved quite easily by introducing a pair of Twistfix helical rods into two separate mortar joints above to span the opening and then repointing so that the helical bars are fully concealed.
Installation of helical bars is simple and rapid method of repairing failed lintels; the process can easily broken down into 10 simple steps.
- Cut a slot in the horizontal mortar bed directly above the first brick course above the lintel to be repaired; if a brick arch is present, this slot should be cut above the arch's crown. It is essential to cut the slot to the correct depth to suit the thickness of the individual wall.
- Remove any mortar or other loose debris, before flushing the joint with plenty of clean water.
- Mix the anchoring grout according to the instructions and load it into a pointing gun.
- Pump grout into the slot until it is around two-thirds full.
- Firmly insert a helical bar, ensuring that it extends 500mm to either side of the window or door below.
- Completely cover the helical bar with grout, before clearing the excess.
- Introduce a second bar to half of the slot depth, ensuring it is at least 10mm distant from the previous bar.
- Fill the slot with grout to approximately 10mm from the surface, making sure that both bars and grout are firmly packed into place.
- Repeat the entire process for at a higher level, which should be four to twelve courses above the first (the greater the distance the more the load carrying capacity.
- Fill the vertical crack with coloured mortar.