Lintel construction has varied through the decades from very elaborate brick arch lintels to less elaborate concrete lintels.
Edwardian & Victorian built properties often feature very elaborate brick arch lintels and having with stood over 200 years of change many of them are showing signs of failure. One of the most common causes of brick arch lintel failure is the change of a load bearing timber window to an uPVC non load bearing window causing the common stepped cracking that apparent on many buildings.
Lintel Repair
Lintel construction has changed with various methods and materials now in use such as flat soldier course lintels, pre stressed concrete lintels and catnic lintels. They can all fail for various reasons such as changes in structural loads, ground movement, and thermal expansion, and in concrete lintels fail due to oxidisation of the reinforcing bar.
Victorian Built Lintels
In the majority of cases, lintel failure can be repaired using the Twistfix heliforce system, incorporating bed joint reinforcement with pinning ties and resin injection forming masonry beams within the structure alleviating the need for costly disruptive remove and rebuild of the lintel which is the traditional approach.
Lintel Repair Using Twistfix Helical Beams
Newman’s are experts in lintel repair and have installed lintel repair schemes across London and the South East.
Subsidence is a common problem in London and the South East of England with an estimated 3.7 million home owners at risk within the region covering over 140,000 postcodes.
Why is subsidence such a problem in London and the South East? Well the majority of the properties within London and the South East are Edwardian or Victorian built and certainly the vast majority were built before the 1970’s. Built on shallow foundations on a clay sub soil which is susceptible to shrinkage and heave with our ever changing adverse weather condition causing changes in ground conditions causing subsidence.
How is subsidence recognised? The location of the cracking for subsidence is normally located around window and door openings in vertical staggered form with the width of the crack normally wider at the top than at the bottom, Heave is different, it is the expansion of the sub soil lifting the building and this is recognised with similar crack locations but often the crack is wider at the bottom than at the top.
Subsidence is caused by ground movement but in order to locate the source of the ground movement obvious factors are undertaken during our survey such as the location of tress which can suck large volumes of moisture from the soil, drains – which in some instances fail causing the soil beneath to wash away. Excavations beneath the ground such as tunnelling for Londons crossrail, expansion of the water and sewage systems and the increasing number of basements can also be the culprit of subsidence.
Subsidence and heave can in some instances be repaired using the Twistfix Heliforce system by creating masonry beams across the brick panels connecting the whole building allowing it to act as one structure instead of individual brick panels that distributes structural loads.
In instances were subsidence cannot be repaired using the Twistfix Heliforce system alone, it is incorporated with either mass concrete underpinning or more conventionally mini piling systems that drive piles down to bedrock or firm made up ground preventing the structure from subsiding or heaving in the event of further ground movement.
Newman Building Solutions were contacted by the owners of this 16th century farm house as they needed advice and costing for the refurbishment of the external fabric of the building as well as improving the security and kerb appeal.
The external rubble filled walls were found to be suffering from delamination so Twistfix delamination grout ties were installed at 450mm x 450mm centres in addition to delamination ties the corners of the property were reinforced and stabilised using 2m long cementitious sock anchors installed at 600mm staggered centres cross pinning the walls.
Deep bed repointing to various areas was also required using a specialist lime mortar.
The main entrance of the property was made secure by constructing two 6ft high solid stone walls with 10ft x 6ft hardwood electric gates and new close board fencing.
