Pitched roof replacement — what a proper job looks like

Not all re-roofs are equal. Done properly, a pitched roof replacement should give you 30-60 years of trouble-free service. Done badly, the same job can be failing in five. The difference is in the bits you’ll never see.

What a proper strip looks like

The first sign of a careful job is the strip. A good roofer:

Strips in sections, not all at once — keeps the roof weatherproofed at every stage of the work
Removes all old felt and battens, not just the broken bits
Doesn’t use the stripped tiles as a work surface for cutting new ones (slivers off old tiles end up in the gutter)

The first sign of a rushed job is a pile of old tiles in the front garden and the new felt going down the same day with no inspection of the timber underneath.

What the timber should look like underneath

Once the old covering is off, the rafters and purlins should be inspected. You’re looking for:

Rot — usually at the wall plate (where the rafter meets the wall), at the valley boards, or where a chimney has been leaking
Woodworm — small round holes in the timber, sometimes with dust around them
Sagging — rafters that have lost their straight line under decades of load

Any compromised timber gets replaced before new coverings go on. A good roofer photographs the bare structure and walks you through what’s been replaced.

What the felt (membrane) should look like

Modern breathable membrane goes on horizontally, lapped correctly at the eaves (over the eaves tray) and at the ridge (over or under depending on the system). It should be taut, not baggy, and taped or sealed at any penetrations.

Things to watch for:

No laps at the eaves — common shortcut. Water gets behind the felt and rots the fascia.
Felt run up between the rafters instead of over them — also a shortcut, leaves the rafters exposed.
Stapled instead of clipped — staples pull out under wind load.

Battens

The batten is what the tiles or slates actually fix into. Get the battens wrong and the whole job is compromised. Things that matter:

Treated timber — should be pressure-treated for insect and fungal resistance
Right size for the tile/slate — usually 25x38mm for slate, 38x25mm or larger for concrete tiles. The wrong size means the fixings don’t have enough purchase.
Spacing accurate to the slate/tile being used — for natural slate, the batten gauge is calculated to give a specific headlap. Get this wrong and the slates don’t overlap enough.
No knots or wane in the timber — knots weaken the batten at the point the nail goes through

Fixings

A roof that’s been “fixed properly” looks very different from one that’s been nailed and prayed. For natural slate:

Each slate should have two fixings (not one, not nailed only)
Copper nails or stainless steel clips, not galvanised
Fixings should be length-correct for the slate thickness and the exposure

For concrete tiles:

Every tile should be nailed or clipped, not just laid
Verge tiles should be mechanically fixed
Tiles at the perimeter (eaves, ridge, verge, valley) need extra fixings

The visible test: tap a few tiles with a knuckle. A properly fixed roof feels solid. A poorly fixed one feels hollow and moves under pressure.

Flashings and valleys

Lead is the traditional material for flashings (where the roof meets a chimney or wall) and valleys (where two slopes meet in a V). Hand-dressed lead is the standard for a proper job:

Code 4 lead for flashings, code 5 or 6 for valleys
Laps of at least 100mm
Proper soakers stepped in with the slate courses, not just stuck on
Welted at the top edge of the flashing to stop wind-driven rain

Things to watch for:

Lead that’s been replaced with cheaper alternatives (acrylic, flashband, self-adhesive tape) without telling you
Flashings that don’t extend high enough up the chimney or wall
Valleys that don’t reach far enough under the tiles

Ridge and verge

Modern practice is dry-fix ridge and verge — a ventilated system with mechanical fixings, not just mortar. Mortar-only ridge is the old method and it does fail, particularly on exposed sites. If you’re having the roof re-done, dry-fix is worth the small extra cost.

What the gutters should look like afterwards

A re-roof usually includes replacing the gutters, fascias and soffits. While the scaffolding’s up, it’s much cheaper to do than coming back later. The new system should:

Be properly aligned with a fall to the downpipes
Have correctly sized downpipes for the roof area
Use compatible brackets and fittings
Have working overflows

The single best test

Ask to see photos of a previous re-roof before the tiles went on. A roofer who shows you bare rafters, fresh membrane, and proper battens is a roofer who takes the unseen work seriously. A roofer who doesn’t have those photos probably hasn’t been doing it.

If you’re comparing quotes and want a second opinion, get in touch — we’re happy to walk you through what’s included.