Wall Defects, Subsidence & Crack Repair | Tenant Guide

Bowing and Bulging Walls

A bowing wall curves outward from its vertical plane. In Victorian and Edwardian terraces, this is often caused by corroded wall ties. A severely bowing wall is a structural emergency. Can it be fixed? Yes, with wall anchors (steel rods tied to the structure), crack stitching, or rebuilding. Bulging wall repair cost ranges from a few hundred to several thousand pounds, all the landlord's responsibility.

If you see evidence of wall anchors already installed, ask your landlord for documentation of the repair and any ongoing monitoring. Gap between skirting board and floor: gaps up to 5mm are common in older properties (floorboard shrinkage). Gaps over 10mm, especially appearing recently or growing, may indicate floor movement or subsidence. Cold walls: report to your landlord in writing. Under the Homes Act 2018, the property must be adequately insulated. Do not carry out permanent insulation work yourself.

Subsidence: Signs, Causes, and Treatment

Subsidence is the downward movement of ground beneath a building, causing uneven sinking. Signs: diagonal cracks wider at one end, stair-step cracks in brickwork, sticking doors and windows, sloping floors, cracks that reappear after filling. What can be mistaken for subsidence? Thermal cracking, normal settlement, and poor construction. A structural engineer can determine the cause.

Common causes in the UK: clay soils shrinking in drought (tree roots accelerate this), leaking drains washing away soil, old mine workings, and soft or filled ground. A subsidence risk postcode checker can indicate whether your area is elevated risk.

Is the landlord responsible? Always yes for structural issues. They must investigate and repair. Confirmation requires a structural engineer or subsidence surveyor to assess crack patterns, monitor over months, and may commission drain surveys and tree surveys. Repair cost: minor stabilised subsidence (crack stitching, a few thousand pounds) to active subsidence requiring underpinning (£5,000 to £50,000+). Landlord's buildings insurance typically covers subsidence.

Is it safe to live in a house with subsidence? Minor, stabilised historic subsidence is usually safe. Rapidly progressing subsidence requires urgent professional assessment. How long does subsidence stay on record? Indefinitely. It must be declared when selling.

Crack Stitching and Structural Repair Methods

Crack stitching: stainless steel helical bars grouted into slots along the crack line. Appropriate for stabilised cracks. Not appropriate for actively growing cracks (the cause must be stopped first). Cost: 50 to 100 pounds per linear metre, total typically 500 to 2,000 pounds. Other methods: resin injection (fine concrete cracks), masonry rebuilding (severe displacement), wall anchors (bowing walls), underpinning (subsidence).

The correct sequence: identify the cause, allow movement to stabilise, carry out structural repair, then apply decorative finishes. If your landlord proposes to fill or stitch cracks without investigating whether movement is active, challenge this. Cosmetic repairs without fixing the cause are not acceptable. For ceiling repairs after collapse: 1,000 to 3,000 pounds for full replacement.

Window Damage and Replacement

Window suddenly cracked: most commonly thermal stress cracking (glass expanding in heat, contracting in cold, with a pre-existing defect). Also caused by structural movement distorting the frame, or manufacturing defects. All are the landlord's responsibility. If you broke it through negligence, you may be liable.

Failed double glazing (condensation between panes): the seal has failed. Not a tenant caused defect. Your landlord should replace the sealed unit. Rotten window frames: the landlord's responsibility. A window that will not close or lock is both a draught and security issue, and a fire safety issue if it is the only escape route (report as emergency).

Draughty windows: your landlord must maintain windows weathertight. They do not always have to upgrade to double glazing, but they must ensure windows seal properly. If the only way to prevent mould and cold is to replace single glazing, this may be a fitness for habitation issue under the Homes Act 2018.

Common Questions