Roof valley repairs and replacements across Sussex
Careful diagnosis and correctly matched repairs for lead valleys, GRP fibreglass troughs, tiled valleys, dry-valley systems and slate roof junctions.
Free quotations · Drone surveys where suitable · In-house scaffolding where required
Why a small valley defect can cause a serious leak
A roof valley is the internal angle where two pitched roof slopes meet. It collects water from both slopes and carries it towards the gutter, so the lining, support and adjacent roof covering all have to work together.
Water entering at a valley can track across membrane, battens or rafters before it becomes visible indoors. That is why an internal stain is not always directly below the external fault. We inspect the complete junction instead of assuming the first visible crack is the only problem.
Lead, fibreglass, tiled and dry-valley systems
There is no single “best” valley for every property. Roof pitch, covering profile, valley length, roof area draining into it, pitch differences and the condition of the surrounding structure all affect the specification.
Lead valleys
Lead is widely used on tiled, slate and period roofs because it can be formed around junctions and detailed to suit varied geometry. A durable installation needs sound support, correctly formed laps and fixings, and room for normal thermal movement.
- Suitable for many traditional and complex roof details
- Local repair may be possible where the remaining lead is sound
- Splits, fatigue, poor falls or widespread deterioration may justify renewal
GRP fibreglass valley troughs
Preformed GRP troughs provide a lightweight, corrosion-resistant drainage channel. Open troughs leave a visible watercourse; dry-valley profiles weather beneath closer-cut tile or slate edges.
- Profile must match the covering, pitch and design requirements
- Continuous support and correct alignment are essential
- Small cut tiles or slates must be secured in accordance with the system
Tiled and close-cut valleys
“Tiled valley” can describe proprietary valley tiles or a close-cut/mitred appearance over a hidden weathering system. Accurate setting out and secure adjacent units matter because water still needs an unobstructed route underneath or between the visible edges.
- Traditional valley tiles may suit certain clay or concrete systems
- Close-cut details can create a discreet finish
- The hidden lining and support remain central to weather performance
Dry-valley systems
Dry-fix valley products can reduce dependence on exposed mortar and are available for different tile, slate and roof profiles. The correct product cannot be selected by appearance alone: manufacturer limits and roof geometry must be checked.
- Options for open, hidden and close-cut appearances
- No assumption that one profile fits every roof
- Head, eaves, overlap and tile-support details are system specific
What sits beneath the visible valley matters
A replacement is not simply a strip of new material laid over the roof. Once the adjacent tiles or slates are lifted, the exposed build-up can be checked and the agreed repairs completed before the valley is reinstated.
| System | Often considered where | Critical checks | Finish |
|---|---|---|---|
| Lead | Traditional tiled/slate roofs and bespoke junctions | Support, falls, laps, fixings, movement and surrounding covering | Visible metal watercourse |
| Open GRP | A compatible preformed trough is appropriate | Correct profile, pitch/capacity, support, overlaps and tile cuts | Visible grey channel |
| Dry/hidden GRP | A close-cut appearance is wanted with a proprietary system | Covering compatibility, central upstand, secure cuts and eaves detail | Narrow or concealed weathering |
| Valley tiles | Compatible proprietary clay/concrete fittings suit the roof | Pitch range, tile family, bedding/fixing method and alignment | Integrated tiled appearance |
Specification note: suitability and detailing are confirmed after inspection and against the relevant manufacturer or project requirements. Exact pitch ranges and capacity limits differ between systems.
Repair or full valley replacement?
We explain what can reasonably be repaired and when renewal is the more dependable option. The quotation sets out the proposed materials and scope before work begins.
A local repair may be suitable when…
- damage is confined to an isolated point;
- the wider lining and support remain serviceable;
- a cracked or slipped tile is causing the problem;
- a defined mortar or detailing defect can be corrected; or
- the repair can integrate reliably with the existing system.
Replacement is more likely when…
- lead is split, fatigued or extensively deteriorated;
- GRP is cracked, distorted or unsuitable for the roof;
- membrane, battens or valley support have failed;
- previous patch repairs are repeatedly leaking; or
- falls, alignment or original installation are fundamentally wrong.
Our roof-valley replacement process
Every roof differs, but the sequence below shows how we approach a typical valley renewal across Sussex and the South Coast.
Survey
Inspect the valley, roof covering, internal signs and connected details. Use a drone for useful high-level imagery where appropriate.
Access
Plan safe access and provide our own scaffolding where the agreed work requires it.
Strip carefully
Lift adjacent tiles or slates and remove the defective valley material without widening the work unnecessarily.
Open-up check
Assess exposed membrane, battens and valley support, then confirm any additional defects before proceeding.
Prepare
Renew agreed support, membrane and battens so the weathering system has the correct base.
Install
Fit the specified lead, GRP, dry or tiled valley detail with suitable head, lap and eaves treatment.
Reinstate
Cut, support and secure the surrounding tiles or slates, replacing damaged units where included.
Finish
Clear the drainage path, inspect the completed junction and provide completion photographs where practical.
Valley work from our existing website gallery
Real roof-valley details already published by Bespoke Roofing, including open weathering, tiled finishes and work during replacement.
Drone surveys, in-house scaffolding and clear quotations
Valleys are often difficult to view safely from ground level. We combine appropriate survey methods with controlled access so recommendations are based on the roof, not guesswork.
Drone roof surveys
High-level imagery can help identify visible cracking, displaced coverings or blocked channels. A close physical inspection may still be needed before final specification.
Our own scaffolding
Where scaffolding is needed, coordinating access within the same company can simplify programming and responsibility.
Written scope and guarantee
The quotation describes the agreed work and materials. Written guarantees are provided for qualifying work according to the system and stated scope.
When Building Regulations may be relevant
A like-for-like local valley repair is often routine maintenance, but requirements can change if the work forms part of structural alteration, a roof conversion or more extensive roof-covering renewal. The correct route depends on the actual project. Where relevant, we can coordinate with Total Building Control; customers can also review the official Building Regulations approval guidance.
Why Sussex homeowners choose Bespoke Roofing
Family-run roofing expertise, coordinated access and a documented approach to repairs across East and West Sussex.
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Download the Bespoke roof-valley guide
A practical introduction to lead, GRP fibreglass, tiled and dry-valley systems, common leak causes, repair-versus-replacement decisions and what to ask for in a quotation.
If the preview does not display in your browser, use the Open PDF button above.
Related roofing and local service pages
A valley leak can involve more than the visible channel. These related pages explain work to adjoining coverings, membranes, ridge junctions, chimneys and complete pitched roofs.
Answers before you arrange an inspection
Can a leaking roof valley be repaired?
Yes, where the defect is localised and the remaining valley lining, support and surrounding roof covering are still serviceable. Replacement may be more dependable when deterioration is widespread or the underlying build-up has failed.
Which is better: lead or GRP fibreglass?
Neither is universally better. Lead suits many traditional and bespoke details; GRP offers proprietary open and dry-valley profiles. The right choice depends on the roof covering, pitch, drainage load, valley geometry, support and desired finish.
What is a tiled roof valley?
The term may refer to purpose-made valley tiles or to a close-cut/mitred appearance. A close-cut valley still requires an appropriate hidden weathering and drainage system beneath or between the visible tile edges.
Do dry-valley systems need mortar?
Dry-valley products are designed to reduce or avoid exposed mortar at the valley. They remain system specific, so compatible components, secure tile cuts, support, overlaps and eaves details are important.
Do you replace membrane and battens around the valley?
Where deterioration is found and the work is included in the agreed quotation, the surrounding covering can be lifted and affected membrane, battens or support renewed before the new valley is installed.
Can moss or debris make a valley leak?
Yes. Accumulated material can slow or divert water, particularly during heavy rain. The valley should be assessed carefully because clearing a blockage will not cure split lining, failed support or defective tile detailing.
Can a drone confirm the full repair?
A drone can provide valuable high-level images and identify visible damage. It cannot always show concealed membrane, support or fixing defects, so a physical close inspection may still be needed before the final method is confirmed.
Will I receive a guarantee?
Written guarantees are provided for qualifying work according to the system installed and the scope stated in the quotation. We explain the applicable terms before work begins.
Which areas of Sussex do you cover?
We cover Brighton, Hove, Worthing, Shoreham, Steyning, Storrington, Horsham and surrounding East and West Sussex areas. Call 01273 447495 for Brighton and Hove or 01903 958694 for West Sussex.