Roof Valley Replacement
Valleys are where 80% of roof leaks start. Old galvanised valleys rust from inside out— by the time you see damage, they're often rusted through. We replace them with Colorbond that lasts 30+ years.
In coastal Frankston, standard galvanised valleys corrode 30-40% faster than inland. If your valleys are 15+ years old, they're likely due for replacement. Don't wait for ceiling stains—get ahead of the problem.
Why Valleys Are Your Roof's Weak Point
Roof valleys collect water from two roof sections and channel it to your gutters. During a heavy downpour, valleys carry far more water per square centimetre than any other part of your roof. This constant water flow, combined with debris accumulation and coastal salt exposure, makes valleys the #1 failure point.
🔴 Signs Your Valleys Are Failing:
- •Ceiling stains near where roof sections meet
- •Visible rust on valley metal (even surface rust is concerning)
- •Paint peeling from valley showing bare metal
- •Lifted or buckled valley sections
- •Valleys over 20 years old (galvanised type)
⚠️ The Hidden Danger:
Valleys often rust from underneath first. By the time you see rust on top, the underside may already have pinholes letting water through. This is why valleys can suddenly start leaking even when they look okay from the ground.
Coastal factor: Salt spray from Frankston beaches accelerates galvanised valley corrosion by 30-40%. Valleys that might last 25 years inland often fail at 15-18 years in our area.
The Solution: Upgrade to Colorbond
Colorbond valleys use BlueScope's Activate technology—a multi-layer coating system specifically designed to resist salt corrosion. Where galvanised fails at 15-20 years in coastal areas, Colorbond typically lasts 30-40+ years.
Get Free Valley AssessmentOur Valley Replacement Process
Precise work for long-lasting results
Roof Inspection & Quote
We get on the roof and inspect every valley closely—looking for rust, pinholes, lifted sections, and debris buildup. We check the underside from the roof cavity if accessible. You get a detailed quote covering exact scope and materials.
Careful Tile Removal
We remove 2-3 rows of tiles on each side of the valley, carefully stacking them for reinstallation. For concrete tiles, we're careful not to crack them. For terracotta, extra care is needed as they're more fragile. Any damaged tiles are noted for replacement.
Remove Old Valley & Inspect
Old valley iron is removed and disposed of. We inspect the underlying sarking/underlay and roof battens. If there's water damage to battens or the sarking is deteriorated, we replace it now—much easier while the valley is exposed.
Install New Colorbond Valley
New Colorbond valley is installed with proper overlaps at joints and correct fall toward the gutter. Valleys are fixed with appropriate fasteners that won't cause galvanic corrosion. Sealant is applied at all joints and penetrations.
Tile Reinstallation
Tiles are reinstalled with correct overhang onto the valley (50-100mm depending on tile profile). This is critical—too much overhang blocks water flow, too little exposes the valley. Tiles at valley edges are bedded with mortar if required.
Clean Up & Warranty
Complete cleanup of all debris and old materials. Water test if conditions allow. You receive 10-year workmanship warranty documentation and care instructions. We also note if any other areas need attention.
Valley Material Options
Colorbond Steel
Premium coastal-rated
BlueScope's Activate technology provides superior corrosion resistance, specifically designed for Australian coastal conditions.
- ✓30-40+ year lifespan in coastal areas
- ✓Salt spray resistant (Activate coating)
- ✓22 colours to match your roof
- ✓BlueScope warranty included
- ✓Won't rust through like galvanised
Our Strong Recommendation
Zincalume
Budget option (inland only)
Zinc/aluminium alloy coating. Good corrosion resistance for inland properties but not recommended for coastal exposure.
- ✓20-25 year lifespan inland
- ✓Lower upfront cost
- ⚠Reduced life in coastal areas (15-18 yrs)
- ⚠No colour options (natural finish only)
- ✗Not recommended within 5km of coast
Only for Inland Properties
Valley Replacement in Mount Martha
Drag the slider to compare before & after
Project Details
- Location:
- Mount Martha
- Roof Type:
- Concrete tile (35 years)
- Problem:
- Two valleys with pinhole rust causing persistent ceiling leaks during heavy rain
- Solution:
- Full valley replacement with Colorbond Woodland Grey, including new sarking
- Duration:
- 1 day
We'd been getting water stains on our ceiling for two years and three different roofers couldn't find the source. Frankston Peninsula Roofing identified the valley pinholes immediately—they're invisible from ground level but obvious once you're up there. No more leaks, even in the heaviest storms.
— Jennifer, Mount Martha
Why Choose Our Valley Replacement Service?
Premium Colorbond
Coastal-rated valleys that last 30+ years
Thorough Inspection
We check battens & sarking while exposed
10-Year Warranty
Written workmanship guarantee
Every Valley Replacement Includes:
- ✓Free detailed roof inspection
- ✓Quality Colorbond valley irons
- ✓Careful tile handling
- ✓Sarking/underlay inspection
- ✓Proper tile bedding at valley edges
- ✓Complete cleanup & disposal
Free inspection • Detailed quote • No obligation
Valley Replacement FAQs
What exactly are roof valleys and why do they leak?
Valleys are the V-shaped metal channels where two roof sections meet at an angle. They're one of the highest-traffic water areas on your roof—during heavy rain, valleys can carry thousands of litres per hour. They leak when: the metal rusts through (especially old galvanised valleys), debris builds up creating dams, tiles aren't properly seated on valley edges, or sealants fail. In coastal Frankston, salt spray accelerates valley corrosion significantly.
How do I know if my valleys need replacing vs. just cleaning?
Clean if: there's debris buildup but the metal is sound—you can see shiny metal once cleaned. Replace if: you see rust holes (even pinholes), widespread surface rust that's flaking, the valley has lifted or buckled, or you're getting leaks despite the valley looking clean. If your valleys are 20+ years old galvanised, they're likely due for replacement regardless of appearance—corrosion often starts from underneath.
What type of valley material do you recommend?
We strongly recommend Colorbond steel valleys for the Frankston/Peninsula area. Colorbond has a superior coating system (Activate technology) specifically designed to resist salt corrosion. It lasts 30-40+ years in coastal conditions versus 15-20 years for standard galvanised. We stock all Colorbond colours to match your roof. For budget-conscious customers, Zincalume is acceptable for inland properties but not recommended near the coast.
What's involved in valley replacement?
Valley replacement is precise work: 1) We carefully remove tiles on both sides of the valley (usually 2-3 rows each side), 2) Remove the old valley iron and any deteriorated underlay, 3) Install new sarking/underlay if needed, 4) Install the new Colorbond valley with proper overlaps and falls, 5) Reinstall tiles ensuring correct overhang onto valley (50-100mm), 6) Bed tiles at valley edges if required. Done properly, you shouldn't need to touch it for 30+ years.
How long does valley replacement take?
Single valley replacement takes half a day to one day depending on length and accessibility. Multiple valleys typically 1-2 days. Complex roofs with difficult access may take longer. We work methodically—rushing valley work leads to problems down the track. Weather dependent: we need dry conditions to work on exposed roof sections.
What factors affect valley replacement cost?
The main factors are: valley length (measured in linear metres), roof pitch and accessibility, number of valleys, tile type (some tiles require more careful handling), whether tiles need replacing, condition of underlay/sarking, and your choice of valley material (Colorbond vs Zincalume). Every roof is different—we provide free inspections and detailed quotes so you know exactly what you're paying for.
Can you colour-match valleys to my roof?
Absolutely. Colorbond valleys are available in all 22 standard Colorbond colours. Most common in Frankston: Woodland Grey (matches Monument/grey roofs), Surfmist (light roofs), Manor Red (terracotta). For tile roofs, the valley is mostly hidden so colour matching is less critical, but we'll recommend what works best with your roof.
What warranty do you provide on valley replacement?
All valley replacement work comes with our 10-year workmanship warranty. If your new valley leaks due to our installation, we fix it at no charge. Colorbond valleys also carry manufacturer warranty on the material itself (corrosion resistance). Combined with proper installation, you can expect 30+ years of leak-free service.
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High-pressure roof cleaning to remove moss and debris
Learn More →Stop Valley Leaks Permanently
Get a free valley inspection and quote. Upgrade to Colorbond for 30+ years of leak-free protection.
✓ Free inspection ✓ Colorbond valleys ✓ 10-year warranty ✓ 30+ year lifespan