- Guide price
- £110–£320
- Repair price
- Confirmed once the leak or damage is found
- Condition survey report
- £140–£280
- Coverage
- England, Wales, Scotland, NI
Monmouthshire at a glance
- Largest towns
- Abergavenny, Chepstow, Monmouth, Caldicot
- Postcode areas
- NP
- Building control
- Monmouthshire County Council
- Neighbouring areas
- Torfaen · Newport · Caerphilly · Blaenau Gwent
- Guide price region
- Wales (−8% on West Midlands rates)
How much does a new roof edge or outlet cost in Monmouthshire?
Guide prices including VAT at Wales rates. We confirm the price once we've traced the leak or seen the damage.
| Job | Guide price inc VAT |
|---|---|
| Outlet or drainage repair | £110–£320 |
| Localised patch repair | £140–£460 |
| Upstand or flashing repair | £230–£600 |
| Emergency temporary weatherproofing visit | £170–£410 |
| Condition survey and leak investigation | £140–£280 |
Which flat roofs are common in Monmouthshire?
Flat roofs in Monmouthshire sit on bungalows with flat-roofed side extensions and dormers, 1930s semis with flat-roofed garages and kitchen extensions and lock-up garage blocks on estates. Wales averages roughly 1,460 mm of rain a year, among the wettest in Britain, so we design for steady run-off: proper falls, clear outlets and upstands well above the finished roof. Approximate 1991–2020 regional averages based on Met Office data.
Building regulations in Wales
Welsh guidance is that most re-roofing needs building control approval, so it's worth checking whenever more than a quarter of a roof is replaced or repaired. Renovated roofs are upgraded to around 0.16 W/m²K where feasible, and new extension roofs are built to 0.13 W/m²K under the Welsh Approved Document L. In Monmouthshire the application goes to Monmouthshire County Council. More on the rules.
Do flat roofs need overflows?
Roofs that drain to internal outlets or behind parapets should normally have an overflow, so that if an outlet blocks, water spills somewhere visible instead of rising over the upstands and into the building.
An overflow is usually a spout or weir set through the parapet or kerb at a level below the top of the upstands. When water runs from it, that is a sign the main outlet is blocked or overloaded. On a simple roof that drains over a drip trim into an external gutter, the open edge itself does the same job.
We look at where the water goes in heavy rain, how many outlets the roof has for its size, and whether the outlets, hoppers and downpipes are clear and properly connected. Leaf guards on outlets help on roofs near trees, as long as they are cleared regularly.
How long do flat roof trims and outlets last?
Properly fixed GRP or aluminium trims and well-installed outlets should last about as long as the waterproofing they are part of. What shortens their life is poor fixing, movement in a rotten deck edge and blockages that are never cleared.
A quick check of outlets and gutters each autumn, and again after storms, prevents most drainage problems. Look for leaves and silt in outlets, gutters pulling away from the fascia, trims that have lifted or split at joints and staining on the wall below the edge. The maintenance guide lists what to check and when. Only check what you can see safely from the ground, a window or a ladder at the edge, and never walk on a roof that isn't designed for it.
Which towns in Monmouthshire do we cover?
Edge trims, outlets and drainage in Monmouthshire: questions
Which towns in Monmouthshire do you cover?
All of Monmouthshire. The main towns have their own pages below, and if yours isn't listed we still cover it: send your postcode and we'll confirm.
How much does a new roof edge or outlet cost in Monmouthshire?
£110–£320 for an outlet or drainage repair, at Wales guide rates including VAT. We confirm the price once we've traced the leak or seen the damage.
Which council handles building control for a flat roof in Monmouthshire?
It depends on where the roof is: in Monmouthshire that's Monmouthshire County Council. Welsh guidance is that most re-roofing needs building control approval, so it's worth checking whenever more than a quarter of a roof is replaced or repaired. We confirm which applies at the survey.
Is some standing water on a flat roof normal?
A thin film that clears within a day or two of rain is common and usually harmless. Deeper water that lingers for days points to poor falls, a sagging deck or a blocked outlet and should be looked at.
How often should flat roof outlets be cleared?
At least once a year, ideally in autumn after the leaves fall, and more often for roofs under trees. A quick check after heavy storms is also worthwhile.
What's the difference between a drip trim and an edge trim?
An edge trim finishes the edge of the roof and holds the waterproofing down. A drip trim has a profile that throws water clear into the gutter. On many roofs a single trim does both jobs.
Everything about edge trims, outlets and drainage → · All flat roofing in Monmouthshire →