There is a crack running up from the corner of the window, wider than it was a month ago. The plaster on the hall wall has started to bulge and flake, and one corner of the bedroom ceiling has begun to sag. You are not sure whether this is serious or simply an old house settling, and your landlord has waved it away as cosmetic.
Some of this is your landlord's to repair and some of it may be nothing. The trick is knowing the difference. This guide covers what your landlord must fix, which cracks matter, and why the law treats a building defect differently from genuine damage.
Are cracks and crumbling plaster the landlord's responsibility?
The structure and exterior of your home are your landlord's responsibility under Section 11 of the Landlord and Tenant Act 1985. That means the walls, the roof, the chimneys, the foundations, and the external doors and windows. It also means the plaster on your walls and ceilings. There was once doubt about whether internal plaster counted as structure, but the courts have settled it: crumbling, blown or damaged plaster is the landlord's to make good.
One thing matters before any of that, though. Section 11 is about keeping things in repair, which means there has to be actual damage. Your landlord has to fix something that has cracked, crumbled, rotted or come apart. They do not have to upgrade a building that is simply old or poorly designed but not yet damaged. That distinction runs through everything below.
It makes no difference that a problem was already there when you moved in. The duty is to put and keep the structure in repair, so a pre-existing crack still counts.
Which cracks are serious and which are only cosmetic?
Not every crack is a sign of trouble, and not every crack is something to claim about. Fine hairline cracks in plaster, the kind that follow seasonal changes or the gentle settling of an older building, are usually cosmetic. They are often a decorating job rather than disrepair.
These are the signs that point to real structural movement and need a closer look.
Cracks worth getting checked
- Cracks wider than about 5mm, or that are visibly getting wider over weeks
- Diagonal or stepped cracks running through the brickwork outside
- Cracks spreading from the corners of doors and windows
- Doors and windows that have started sticking or won't close
- Floors that have begun to slope, or gaps opening between walls and ceilings
- Plaster that sounds hollow when tapped, or has started to bulge
Several of these together can mean subsidence or structural movement, which is your landlord's to investigate and put right. You do not have to diagnose the cause yourself. A surveyor does that, and a surveyor's report is often what proves the difference between a cosmetic crack and structural damage.
Does my landlord have to fix a design fault or only the damage?
This is where landlords push back, so it is worth understanding. The duty under Section 11 is to repair, not to improve. If a wall is simply too thin, or the home was badly designed and gets cold or condensation-prone, that on its own is not disrepair, and your landlord does not have to redesign the building. The courts have held that there has to be physical damage to something before the repairing duty bites.
The flip side matters as much. Once part of the structure has been damaged, your landlord has to repair it properly, and that can mean fixing the underlying cause rather than papering over it again and again. What they do not have to do is effectively rebuild the place to a higher standard than it was let to you.
If your real problem is a cold, condensation-prone home rather than damage to the structure, there is a separate route through the fitness rules. See the Fitness for Human Habitation Act and tenant claims.
When is a crack or sagging ceiling an emergency?
A ceiling that is sagging, bulging or shedding plaster, a wall that is bowing, or any sign that part of the structure could come down is an emergency. Treat it as one.
Keep out of the room, move anything valuable if you can do so safely, and report it as an urgent danger straight away. A water-heavy or cracked ceiling can come down without warning. If your landlord does not act quickly, your council can carry out emergency repairs itself where there is an imminent risk of serious harm, and in the worst cases can ban the use of part of the home until it is made safe.
If a structural failure has already injured someone, your landlord can be liable for that injury on top of the repair, so keep medical records and photos of what caused it.
What to do and what you can claim for structural damage
Report the problem in writing and keep a copy, since the repair duty starts when your landlord knows. Photograph the cracks and sagging with something for scale, like a coin or a ruler, and take fresh photos every week or two so you can show whether it is getting worse. Keep a dated note of when you first reported it.
If your landlord does nothing, your council's environmental health team can inspect for free, and a real collapse risk is the kind of serious hazard they have a duty to act on. The wider process is in how to handle a disrepair case, and the council route is in how to report a landlord to the council.
Where your landlord has left genuine structural disrepair, you can claim compensation, usually a share of your rent for the period, plus the cost of anything the damage ruined. The figures are in how much you can claim for disrepair. And since 1 May 2026 there is no more no-fault eviction, so raising a structural problem cannot get you a Section 21 notice.
If your home is cracking or a ceiling is failing and your landlord is stalling, Remedy can tell you whether it is disrepair they must fix, what you may be owed, and draft the letter that gets it taken seriously. Start a free assessment at remedylegal.ai.
