How to Repair Masonry Lintels Using Helical Bars? Brick Lintel Failure

Lintel failure is a common type of issue faced in building structures, irrespective of the type of lintel constructed. All the openings in a building say, windows and door opening will have a lintel over it. 

Among masonry, steel, or concrete lintel, brick or masonry lintels are easy to repair using helical bars. Helical bars can be used for an affected brick or masonry lintel as an alternative for replacing the lintel. Helical bars help to improve the strength of lintel without having too much disruption or disturbance to other structural elements. 

Brick Lintel Failure

The problems in brick lintels are observed as diagonal cracks or step cracking in the masonry above the doors and the windows. Abrupt action can help to avoid future costs and disruption. 

The brick lintel constructed can either be in the form of a curved arch or in the form of a straight flat arch as shown in figure-1 below. In both cases, the masonry lintel uses its compressive strength to transfer the vertical loads coming over it horizontally to the brick abutments on either side of the opening. These lintel units are often supported by a frame either made of wood or steel. 

When this below frame is no more effective, the lintel starts to sag and brickwork starts to crack. Simple repair cannot solve this issue. Instead, we need to introduce reinforcement into the masonry above the opening so that it takes the role of a load-carrying beam. Here the repair of a masonry lintel using helical bars are explained in step by step procedure.

Also Read: How to Identify Serious Wall Cracks?

How to Repair Masonry Lintel Using Helical Bars?

Helical bars must be inserted in two levels.

STEP 1: Cutting Slots

Cut a slot in horizontal mortar bed above the first course of the brick that is lying above the lintel.

 In the case of a arched masonry lintel, the slot must be cut above the crown of the arch as shown in figure below.

The cut must be provided just over 500 mm on either side of the opening and above the window or door. The depth of the cut is dependent on the wall thickness. The below chart can help.

The slots made must be cleaned out of debris and washed using water. Do not leave water in the slot.

STEP 2: Grouting

Prepare a anchor grout and pump the specialist grout into the incision and fill between one-half and two-thirds full.

STEP 3: Insert the Helical Bar

Push the first bar firmly into the ground to around 2/3rd of the depth of the slot. Once inserted, make sure that the helical bars extends 500mm either side of the window or door.

Now insert the second bead of anchor grout into the slot. Make sure that the first bar is completely covered. Excess grout must be troweled away before inserting the second helical bar. 

The second bar is placed around half the depth of the slot and must keep a spacing of 10 mm from the first bar.

Always make sure that the bars and the grout are packed firmly.

The second level is repeated in the same way. The second level is performed by making a slot four courses above the first, employing the same method.

STEP 4: Finishing

Finish by making good the slot and filling the vertical crack with an appropriate filler to match. By using the right filler to repoint, you should leave no evidence of the repair work.

Note: When there isn’t a lintel above a window, it usually means the masonry was built directly onto the window frames. In this instance you can create a new lintel using helical bars. You can do this by installing two levels of helical bars using the method outlined above.

Price of Helical Bars for Lintel Repair

As per PermaCEM:

6mm x 3 metre - 50 pack - £440 exc. vat
8mm x 3 metre - 50 pack = £595.00 exc. vat
6mm x 7 metre – 5 pack = £110 exc. vat

Bars can also be purchased individually:
6mm x 3 metre - £9.75 per bar exc. vat
8mm x 3 metre - £12.80 per bar exc. vat

Installing helical bars in this way enables you to form a lintel within the existing brickwork. It is a cheaper and easier repair than installing a new concrete or metal lintel, which is expensive and very disruptive.

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