Slate Roof Repairs Dublin — Nail Sickness, Delamination & Storm Damage

Walk through Rathmines, Phibsborough, Drumcondra, or almost any terrace built before the 1960s and you're looking at natural slate roofs, many of them still on their original covering from the 1870s through to the 1920s. That's not an accident — a properly laid natural slate roof can genuinely outlast the building underneath it.

Which is exactly why so many "we need a new roof" conversations start from the wrong diagnosis. The slate itself is very often still fine. What's failed is something else entirely.

Mr Roofing repairs slate roofs across Dublin — re-fixing, re-slating, and matching materials on period properties. Free inspection, 25-year guarantee, and an honest answer on whether your roof needs a repair or whether it's actually still doing its job.

Slipped & Loose Slates

The most common callout, and almost always down to a failed fixing, not a failed slate. Re-fixed and checked against its neighbours.

Nail Sickness

Where the original fixing nails have corroded across a section of roof, causing repeated, spreading slate slippage. Diagnosed properly rather than treated one slate at a time.

Cracked & Delaminated Slates

Slate that's split, cracked, or begun separating into thin layers — replaced and matched to the surrounding roof.

Storm-Damaged Slate

Wind-lifted or dislodged slates following bad weather, made safe and re-fixed.

Re-Slating & Partial Re-Roofing

Where a section — or a whole roof — genuinely needs stripping and re-laying rather than repeated repair.

Slate Matching for Extensions

Matching new slate to an existing roof when a rear extension or dormer meets the original roofline.

Nail sickness is the real culprit behind most "bad slate roof" diagnoses.

Natural slate can genuinely last a century or more — it's the nail holding it on that has a shorter lifespan. Original fixings from Dublin's Victorian and Edwardian building boom were often iron or steel, and after decades of damp exposure, those nails corrode and fail. The slate itself is frequently in perfect condition; it's just no longer attached to anything. This is why one slipped slate is rarely an isolated event — if one nail's gone, everything fixed the same year, in the same batch, is on roughly the same clock. A roof with widespread nail sickness needs re-fixing or re-slating across the affected section, not a slate-by-slate chase that never actually catches up.

Delamination is a different problem, and it does mean the slate itself has failed.

Unlike nail sickness, delamination is genuinely about the slate — moisture getting between the natural layers the stone is formed from and gradually splitting it apart, often starting as a hairline separation you'd only spot up close. Once a slate's delaminating, it's genuinely reached the end of its life and needs replacing, not re-fixing.

Cement pointing on slate ridges causes more cracking than it prevents.

Ridge tiles and hip junctions are traditionally bedded in mortar, and — same issue as chimneys — using a rigid modern cement mix rather than a more flexible lime-based mortar means the joint can't move with normal thermal expansion. The result is cracking that lets water in exactly where the roof was supposed to be sealed.

Matching matters more on slate than almost any other material.

Slate isn't uniform — Bangor Blue, Valentia, Killaloe, and Welsh slates all differ in colour, thickness, and how the nail holes sit, and even slate from the same quarry can vary slightly by batch. A repair using the wrong slate doesn't just look wrong; a thickness mismatch of even a few millimetres can be enough to break the weathering pattern the whole roof relies on, and give wind somewhere to get a grip. We match to what's already on your roof, sourcing reclaimed slate where it genuinely gives the best match.