Sagging Roof Ridge
The ridge line along the top of the roof has a visible dip or sag instead of running straight.
What Is Causing This?
- 1Ridge beam or rafters weakened by rot or woodworm
- 2Original timbers undersized for the roof span
- 3Rafter feet spreading outward over time
How Urgent Is This?
This needs prompt attention. Delaying could cause further damage, safety risks, or significantly higher repair costs.
What Needs to Be Done
A roofer and structural engineer will assess the roof structure. Repairs may involve adding support timbers, replacing damaged rafters, or installing a new ridge beam.
How Much Will It Cost?
National average estimate
Labour: £975 – £2,575 | Materials: £725 – £2,050
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Prices are estimates based on typical UK rates. Actual costs depend on the specific issue, accessibility, and your location. All quotes from tradespeople on Tradesfolk are completely free.
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Ask a QuestionPlanning Permission Guidance
Some fixes for this problem may require planning permission or building regulations approval. Check if your project needs permission:
How to Prevent This
Ensure the loft is well ventilated to prevent timber rot. Have any woodworm treated promptly. Check the roof structure when carrying out loft insulation work.
Related Problems
Water coming through the roof into the loft space or directly through the ceiling, often during or after rainfall.
One or more roof tiles have slipped, cracked, or blown off, leaving exposed areas on the roof.
Visible moisture, water droplets, or damp patches on the underside of the roof felt or rafters in the loft space.
Other Roofer Problems
One or more roof tiles have slipped, cracked, or blown off, leaving exposed areas on the roof.
Water coming through the roof into the loft space or directly through the ceiling, often during or after rainfall.
Rainwater overflows from the guttering during rainfall, running down the outside walls of the house.
Thick green moss growing across roof tiles, particularly on the north-facing side of the roof.