Often, lintel support is insufficient; whether this is due to general deterioration of the building over time due to settlement and movement, or that the flashing was incorrectly installed or even worse never installed. The steel lintels will eventually start to rust, corrode and deteriorate. Signs of lintel and brick arch failure becomes evident; typical signs are diagonal or stepped cracking at the tops of windows or door heads
When cavity walls were first introduced, it was common practice to construct the outer leaf of the cavity without a lintel reinforcement, with the brickwork supported by the load bearing window frame. Often, especially when windows have been replaced, the lintels start to sag, or diagonal cracks (almost into a triangle) start to appear at the corners of windows. This is because, in this instance, the original timber windows were helping to support the outer masonry skin. Once replaced, the new windows had insufficient load bearing capacity, causing the masonry to crack. Left unchecked, the cracks in the wall are liable to worsen.
As the lintels fail, or are non-existent, we suggest, in effect, installing new lintels to replace the existing lintels. Our highly skilled Mechanics cut two horizontal grooves vertically above the window. Two pairs of high tensile stainless steel helical bars are embedded into the wall with a specialized grout to temporarily shore up the facade while the new lintel is being installed. Once the lintels are installed correctly it is good practice to install flashing and a weeping system to deflect water away from the header.