We carry out underpinning and subsidence repairs in Allerton, L18, always to a chartered structural engineer’s design and with Building Control involved where the regulations apply. Most calls from here are about cracking around bay windows or near mature trees, and many of those end without any underpinning at all once the cause is found and dealt with.
Which Allerton homes do we hear about most?
Allerton sits in L18, with parts of the district in L19, and is looked after by Liverpool City Council. Its housing is mostly inter-war semi-detached and detached homes, many with two-storey bays, alongside some larger Victorian and Edwardian houses. Gardens tend to be generous, and many roads are lined with street trees. Calderstones Park is close by for a lot of residents.
None of that means a house here is moving. It does mean that the features which most often lead to questions are common: bay fronts that may sit on shallower footings than the main walls, large trees within reach of the house, and decades of additions such as porches, garages and rear extensions.
Why do bay fronts crack first?
On many inter-war and older houses the bay was built with a lighter, shallower foundation than the rest of the front wall. If the ground beneath dries, softens or settles, the bay can move a little on its own and open a crack where it meets the main wall, or above the window head. A corroded or undersized lintel produces cracking in a similar place, which is why a proper look matters before anyone talks about foundations. Our page on bay window subsidence repair explains the options, from lintel work to partial underpinning designed by the engineer.
Partial underpinning of a bay can create a stiff section next to unaltered foundations. The engineer has to design for how the two parts will behave together, so this is never a quick fix.
Mature trees: what matters and what does not
Trees draw moisture from the ground, and on shrinkable clay that can lead to subsidence in dry spells. NHBC guidance lists oak, poplar, willow and some other species as high water demand. A tree being near your house is not proof of anything, though, and taking one down on clay can bring its own problem: the ground can swell back, known as heave. Any tree decision should follow advice from an arboriculturist and the engineer, and you should check with the council first in case a Tree Preservation Order or conservation area rule applies.
What happens on an Allerton visit?
- We ask where the cracks are, how wide they look, whether they are new and whether doors or windows have started sticking.
- We look at the outside walls, the bay, nearby trees, gullies and drain covers, and any extension junctions.
- If the cause is not yet clear, we recommend a structural engineer’s inspection and, where needed, a drain CCTV survey, trial pits or crack and movement monitoring.
- When there is a diagnosis, we explain the options in plain English and quote in writing for the engineer-designed scheme.
For semis, digging close to the shared wall usually means the Party Wall etc. Act 1996 needs to be considered, and a party wall surveyor handles the notices.
Close to Allerton
We also cover neighbouring Mossley Hill and Woolton, and the period streets of Aigburth towards the river. For the full picture of how we work, see our page on underpinning in Liverpool, or read more about local underpinning and subsidence repair across the city.
Noticed cracks at home in Allerton?
Ring 07777 659786 and tell us where they are and how long you have seen them. We will call back, talk it through and arrange a visit if one is needed.
Frequently asked questions
Does a crack above my bay window in Allerton mean I need underpinning?
Not necessarily. Bay cracking is common and has several possible causes, including a failed lintel, a shallow bay footing or movement in the ground. Many cases are fixed by dealing with the cause and repairing the masonry. Only a chartered structural engineer can say whether the bay needs underpinning, usually after an inspection and sometimes after monitoring.
A neighbour’s tree is close to my house. What should I do?
Do not cut or remove it yourself and do not ask for it to be felled on a hunch. Photograph and date any cracks, tell your buildings insurer if you suspect subsidence, and let the engineer and an arboriculturist advise. Speak to your neighbour once you have advice, and check with Liverpool City Council whether a Tree Preservation Order applies.
Will Liverpool City Council need to be involved in my underpinning?
Usually, yes. The Planning Portal says approval under the Building Regulations will normally be required to underpin an existing foundation. Building Control, either the council or a registered building control approver, inspects the work at key stages. We deal with the notices as part of planning an engineer-designed scheme.
How long does it take before work can start in Allerton?
It depends on the property, the cause and the permissions. If monitoring is needed, readings are often taken over many months, and party wall notices on a semi add time before any digging. Once a scheme is agreed, the time on site depends on the method and the length of wall involved.
Can you visit if my insurer is already handling a claim?
Yes, but the insurer and its loss adjuster decide on investigation, monitoring and the repair. We can explain the stages of a claim and carry out a scheme the insurer has agreed. Read more about subsidence insurance claims.