Subsidence is the downward movement of the ground supporting the building, where the movement is unconnected with the weight of the building. Essentially, the soil beneath the building’s foundations is unstable and settlement occurs when the ground bearing the structure yields under the load of the building. It compresses to such an extent that the structure settles at the point of failure. Particular problems arise when the movement varies from one part of the building to another and causes walls to crack.
Why it is Important to Rectify Subsidence Quickly?
Cracking due to subsidence will affect the sale of your property. When selling, banks may be reluctant to finance the purchase of property with subsidence problems. If you sell it may be to a very restricted pool of purchasers e.g. cash buyers from a building background. Once subsidence is discovered on a survey by a purchaser, they may naturally request a large discount on price to cover potential repair costs. If left unresolved the repairs costs can escalate resulting potentially in rebuilding large sections of the property at much greater costs.
PKT Subsidence Engineers & Loss Assessors
PKT as chartered engineers can certify subsidence repairs to reflect the fact that the building has been returned to its condition prior to the problem. We are based in Dublin and have been investigating subsidence problems for 28 years. We can manage your subsidence repair and insurance claim from start to finish and prepare a structural report for submittal to your insurance.
We can tender the repairs to specialist contractors on your behalf, who will offer an additional guarantee for the works to be covered. If Underpinning works are required we will advise on design options. We will carry out interim inspections of the construction phase including underpinning and structural repair works with certification upon completion. Therefore you have piece of mind that the works have been overseen by a chartered engineer to ensure they meet the specification and budget.
When we discovered we had subsidence problems in our house we employed PKT consulting engineers. PKT took over, all dealings with insurance company's assessors, the piling engineers and the builders. Kevin Tierney identified the extent of our problem designed the solution and oversaw the piling engineers and the builder's implementation of that solution. Kevin oversaw every part of the project from start to finish. We felt he made sure we got everything we paid for and weren't charged for what we didn't need. All in all, he took an 85 year old house suffering from subsidence and made sure it has been left rock solid for the next 100 years. Kevin was a pleasure to deal with straight forward and easy to talk to. We would have no hesitation recommending PKT Consulting Engineers. Brendan & Valerie, Drumcondra
Kevin looked after the project from claim stage when he diagnosed subsidence. He dealt with the insurance claim, applied for planning for my protected period house, tendered the project and oversaw construction. I found him to be efficient, cheerful with a can do attitude and he was available to me whenever I needed to contact him. He was also dogged, persistant and determined when negotiating with the difficulties of what was a complex building project. I would definitely recommend Kevin's expertise. Deirdre, Rathgar. 7.4.2015
Signs Of Subsidence
Identifying the cause of subsidence begins with exploring its consequences. The emergence of cracks is the first obvious signs of subsidence. Nevertheless, not all cracks indicate that there is a problem. There could be movement in the ground beneath your building if you find:
- • Vertical and diagonal cracking concentrated in specific areas tapering in width between the top and bottom of the building. Horizontal cracks may also occur.
- • Cracks extending through the DPC down into the foundations.
- • External cracking reflected internally in the same area of the wall.
- • Deformity of doors and windows, which are weak areas in a building, causing doors and windows to stick.
- • Floors sloped and walls leaning.
- • Rippling wallpaper that isn’t caused by damp.
Causes Of Subsidence
- • Certain soils: Clay soils are particularly vulnerable to subsidence since they shrink and swell depending on their moisture content. The compression of filled ground can also cause subsidence.
- • Vegetation: Trees and shrubs take moisture from soils causing them to shrink. This is intensified during long dry spells of weather as roots extend in search of water.
- • Leaking drains and watermains: Leaking drains and watermains can weaken the supporting subsoil or wash out the fine minerals within the soil, causing settlement of the building foundation.
- • Property location: Problems may occur where houses are built over, or close to mining and quarry works. This is not that common.
- • Excavations adjacent to building: Can cause subsidence unless proper precautions are taken to support the building in advance and restraining the sides of the excavation.
- • Vibration: The ground compacts and shrinks, weakening the subsoil, reducing the capacity of the subsoil to support the building above.