Failure of a lintel will be due to either decay, fracture or loss of support to the supporting abutments allowing the arch to spread or drop.
Look for misplaced arch segments, sagging courses above the arch and cracks in the abutments.
A combination of a beam and grout ties can be used to effect a non-visible repair.
The exterior walls of most twentieth and twenty first century buildings consist of two parallel leaves of brick or block work approximately 50mm apart. Metal wall ties hold these wall leaves together. Metal wall ties were initially made of either wrought iron or mild steel without any rust protection and it was not until later that galvanised steel tiles became the norm. Even then, the quality of galvanising was extremely variable and thus, in houses built before World War 2, it is quite common to find that the wall ties have corroded.
Wall Tie failure can produce a variety of symptoms depending on the type of tie, mortar, brickwork etc. Look for regular horizontal cracking, increasing towards the top of the building at every 4 or 5 courses.
In most instances, wall tie inspections can be carried out by Insitu SCP staff with a minimum of disruption and, where necessary, new stainless steel wall ties can quickly be inserted in place of the corroded ones.
Subsidence can be caused by: certain soils (clay soils are particularly vulnerable to subsidence since they shrink and swell depending on their moisture content), trees and shrubs taking moisture from soils causing them to shrink, leaking drains, which can soften or wash away the ground beneath the foundations and, less commonly, where properties are built over, or close to, mine workings.
The first obvious sign of subsidence is the appearance of cracks. These will normally be small diagonal cracks, about the thickness of a 10p coin, which appear suddenly in plasterwork and outside brickwork. Doors and windows may also start to stick due to the distortion of the building.
Most buildings experience some minor cracking at one point or another due to changes in temperature and humidity. Most minor cracks are nothing to worry about.
Bars, ground screws and flexible grout are used to restore the structural integrity of the wall. These devices distribute the forces evenly along the wall reducing the possibility of mirror cracking later on.
Please contact us to discuss your requirements and we will do our utmost to assist you. Insitu SCP are one of the most established names in building preservation in the South East of England, with over 40 years experience in the industry. You can be assured that we will identify potential issues, find the best solution and deliver long lasting results with minimal disruption.