Slate Roof Storm Damage in Barry: Repair or Replacement?

The Slate Is Rarely the Problem

Welsh slate is one of the most durable roofing materials ever put on a building. Slates taken off a roof after a century are frequently sound enough to lay again, which is why reclaimed slate has a market at all.

What has a service life is the nails. A slate is held by two of them near its head, and they sit in a damp, ventilated roof space corroding slowly for decades. In salt-laden air off the Bristol Channel, they corrode faster.

So on a Barry slate roof the question is almost never "is the slate finished?". It is "are the nails finished, and over how much of the roof?"

The Evidence That Answers It

What came down

• Whole slates with clean holes: the nails failed. Corrosion.
• Whole slates with rusted nail fragments still in them: the same, further advanced, and the clearest evidence you can have.
• Broken slates: something struck the roof, or the slate itself has delaminated. More likely local.

The pattern of loss

• One area, once: probably local. A repair is likely right.
• Several unconnected areas in one storm: a general condition.
• Repeat losses in successive storms, in different places: the clearest signal of all, and the one people ignore longest because each individual repair seemed reasonable at the time.

What can be seen on the roof

• Slates that have slipped but not fallen, scattered across the slope
• Whether nails withdraw easily when a slate is lifted
• The condition of the battens, which corrode-adjacent nails often take with them
• Whether there is underlay at all, and if so what condition it is in

What Each Option Actually Involves

A repair

Replace the missing slates, re-secure the immediate area, check and make good the surroundings. Quick, much cheaper, and completely right where the fixings around it have life in them. Anyone who tells you a roof needs replacing when this would do is not being straight with you.

A recover

Strip the slate, replace the battens and the underlay, and relay the covering — often reusing a good proportion of the original slate, because the slate is usually the part still fit for service. Several times the cost, and it resolves the roof for decades.

Worth knowing: a recover on a coastal roof is also the opportunity to fix the underlying problem rather than repeat it. Fixings specified for a marine atmosphere, and mechanically fixed ridge and verge rather than mortar, mean the next few decades do not follow the same script as the last.

The Arithmetic Nobody Does

This is where the decision is usually lost, and it is worth working through plainly.

Access is a large part of the cost of any roof repair, and you pay it in full every single time somebody comes out. On a two-storey Barry terrace that can be a substantial proportion of a small repair.

So three repairs over three winters is not three small bills. It is three lots of access, three call-out costs, three sets of disruption, and a roof that is still no better than it was. That is how a sequence of sensible-looking decisions ends up costing more than the recover would have, and it happens gradually enough that nobody notices until it has.

None of which means recover is the answer. It means you should ask for both priced, with a view on how long the repair is expected to hold, and make the comparison with real numbers rather than instinct.

What a Recover Quotation Should Tell You

Because it is a large sum, and because the differences between two recover quotations are usually in things that are not obvious from the totals.

• What proportion of the existing slate is expected to be reusable, and what happens if it turns out to be less once the roof is open
• What new slate will be used for the balance, and how closely it will match
• Whether battens are being replaced — on a roof of this age they generally should be, and a quotation that reuses them is quoting for something different
• What underlay is specified, and whether there was any before
• What fixings, and specifically whether they are suited to a marine atmosphere. On a coastal roof this is the single most important line in the quotation and it is frequently absent
• Whether ridge and verge are being mechanically fixed or re-bedded in mortar
• Scaffolding, and how long it is included for
• What guarantee is offered, by whom, and what it actually covers

A recover on an exposed coastal roof, put back with standard fixings and mortar bedding, is the same roof again with the same future. If nothing in the quotation addresses why it failed, ask.

Signals That Point Towards Recovering

• Slates coming down undamaged, repeatedly, from different areas
• Slipped slates visible across the whole slope rather than in one place
• No underlay beneath the slate, or underlay that has perished
• Battens that are soft, split or corroded around the fixings
• Daylight visible through the roof in several places from the loft
• A history of repairs at roughly annual intervals

Signals That Point Towards Repairing

• Broken slates rather than whole ones
• Damage in one identifiable place with an identifiable cause
• Sound underlay in good condition
• Nails elsewhere on the slope that hold when tested
• A roof that has been trouble-free for years until this storm

T & T Roofing South Wales will tell you which of these we think you are in, and why, and quote accordingly across Barry. If the answer is a repair, that is what we will quote for — it is a short-lived business selling people roofs they do not need.