Hampstead Architecture and Planning

Haringey

House Refurbishment Architects in Tottenham

Re-roofing is the largest single item in most refurbishment budgets and the one most often recommended when it is not yet needed. A roof that is losing slates is not necessarily a roof at the end of its life, and the difference between a repair and a replacement is a judgement about the fixings and the structure rather than about the covering you can see.

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The short answer

Does a Tottenham roof need replacing or repairing?

It depends on the nails and the battens, not the slates. General corrosion of the fixings means slates will keep slipping faster than they can be replaced, which is terminal for the roof as laid — but the slate itself is often sound and worth salvaging for the visible slopes. Check the chimney flashing and the gutters before concluding anything, since they cause more internal damp than the covering does, and decide on insulation before the scaffold goes up.

Planning at a glance

Tottenham

Planning at a glance in Tottenham
Local planning authorityHaringey
Likely approval routeHouseholder planning application or permitted development, depending on conservation status, listing and property type — confirmed for the exact address before drawings begin
Statutory determination time8 weeks for most householder applications (13 weeks for major applications)
Where most projects startPlanning Route Review — £395 inc. VAT, credited in full against your package if you proceed. Find my package →

Diagnose before deciding. Most Victorian and Edwardian roofs here were covered in natural slate fixed with iron or steel nails, and the usual failure is not the slate but the nail: the fixings corrode, individual slates slip, and the roof appears to be failing while the slates themselves remain sound. That condition — nail sickness — is genuinely terminal for the covering as fixed, because slates will continue to slip faster than they can be replaced, but it says nothing about the quality of the slate, which can often be salvaged and re-laid.

The distinction that matters is therefore between a roof with localised damage and a roof whose fixings or substrate have failed generally. A handful of slipped slates after a storm is a repair. Slates slipping steadily across several slopes, with rust staining below the fixings, is a re-roof. So is a roof where the battens have decayed or the underlay has embrittled and torn — both of which are invisible from the ground and are established by lifting a small area rather than by a look from the street.

Weight is the decision people get wrong when the covering is changed. Concrete tiles are considerably heavier than natural slate, and a roof structure sized in the nineteenth century for slate was not designed to carry them. A great many houses were nonetheless re-roofed in concrete during the twentieth century, and the results range from no visible effect to spread rafters, deflected purlins and pushed-out walls. If your house has a concrete tile roof on an original structure, that is worth having looked at — and if you are replacing a concrete roof, going back to a lighter covering is a structural improvement as well as usually a visual one.

A re-roof is also the cheapest opportunity you will ever have to insulate at rafter level, and the decision has to be made before the scaffold goes up. With the covering off, insulation can be installed over or between the rafters as part of the same operation, which is a fraction of the cost of doing it later from inside and does not consume head height in the same way. Whether that is worth doing depends on whether the loft is ever likely to be converted — but it is a question to answer now rather than to discover later.

Local analysis

What matters in Tottenham

Repair or replace: what actually determines the answer

Roofing quotations tend to arrive as a binary — patch it or replace it — and the honest answer depends on three things that have to be looked at rather than assumed. The first is the fixings. Natural slate on these houses was nailed, historically with iron or later steel nails, and those nails corrode long before the slate does. Once corrosion is general, slates begin to slip across the whole roof, and each repair is followed by another somewhere else within a season or two. That is the classic signal for a full strip and re-lay, and it is identified by looking for rust staining, by the pattern of slipped slates across multiple slopes, and by lifting a slate to see the fixing condition. The second is the substrate: the battens the slates are fixed to, and the underlay behind them. Battens decay where they have been persistently wet, particularly at valleys, around chimneys and at the eaves, and nails cannot hold in rotten timber whatever their own condition. Traditional bituminous underlay embrittles with age and tears, so wind-driven rain that gets past the covering — which is normal, since a slate roof is not a sealed layer — reaches the structure instead of being shed. Neither is visible without opening a small area, which is the single most useful thing a roofer can do before quoting. The third is the covering itself. Good natural slate lasts a very long time and is frequently in better condition than the roof it is on, which is why salvage and re-lay is a real option: the sound slates come off, go back on the most visible slopes with new fixings and new battens, and new material fills the shortfall on the least visible elevations. That approach costs more in labour and less in material than a full replacement, keeps the weathered appearance a designated street depends on, and is often the right answer where the slate is good and the fixings are not.

Chimneys, flashings and rainwater goods — where the leaks actually are

A surprising proportion of what is diagnosed as a failed roof is in fact a failed junction, and replacing the covering without addressing the junctions produces a new roof that leaks in the same places. Three areas account for most of it. Chimney stacks are the first and the worst: the flashing where the stack passes through the roof, the flaunching that beds the pots, the pointing on the stack itself and, on a stack no longer in use, the absence of any ventilation to let it dry. A stack that has been left to decay lets water into the roof and into the flue, and the damp appears on the chimney breast two floors below, where it is invariably attributed to something else. On a designated street the stack is also part of the roofline, so capping it with a vented cap is far preferable to taking it down. Second, valleys and abutments: the junction where two roof slopes meet, and where a roof meets a wall or a neighbouring building. These are where water concentrates, where debris collects and where lead detailing is either right or leaking. A valley formed in a material that has hardened and cracked will leak regardless of the condition of the slates either side of it. Third, rainwater goods, which cause more damp in these houses than any defect in the roof itself. A cracked or blocked gutter, a downpipe discharging against a wall rather than into a gully, or a hopper full of moss puts water repeatedly onto one part of the elevation, and the resulting internal damp is routinely diagnosed as rising damp and treated as such. Checking gutters and downpipes properly — ideally in heavy rain, when the failure is visible — costs nothing and should precede any expensive conclusion about the roof or the walls.

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Local planning

Planning & conservation context

Re-roofing in the same or a closely similar material is generally repair and maintenance rather than development, so it usually needs no planning permission. Changing the appearance of the roof — a different material, colour or profile — is a different question on a designated address.

Rooflights inserted during a re-roof fall under Class C on an undesignated house, subject to conditions including that they must not project more than 150 millimetres beyond the plane of the slope. On a designated front slope a conservation pattern is normally expected.

Building regulations apply where the work is substantial. Renewing a significant proportion of a roof covering is controlled work, and it triggers a requirement to improve the thermal performance of that element where it is reasonably practicable to do so.

Inside a designation the roof covering is a substantial part of what is seen from the street, so replacing natural slate with concrete tile changes the appearance of the building and is generally resisted — and on a house within an Article 4 direction such as Peabody Cottages, the position should be checked against the direction itself.

Where original natural slate survives, sound slates are worth salvaging and reusing on the most visible slopes with new material confined to the least visible, which keeps the weathered appearance at a manageable cost.

Chimney stacks, ridge detail and the profile of the eaves contribute as much to a designated roofline as the covering does, so a re-roof is the moment to repair them rather than to simplify them away.

For the wider local-authority picture — policies, timescales and application routes — see planning in Haringey.

Illustrative study — street elevation

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Architecture in Tottenham: FAQs

How do I know if my roof needs replacing?

By looking at the fixings and the substrate rather than the covering. Slates slipping steadily across several slopes with rust staining below the fixings indicates the nails have corroded generally, which is terminal for the roof as laid. Decayed battens or torn underlay do the same. A handful of slipped slates after a storm is a repair. All of it needs a small area lifted rather than a look from the street.

What is nail sickness?

The general corrosion of the nails holding the slates, which happens long before good slate itself deteriorates. Once it is general, slates slip across the whole roof and each repair is followed by another within a season or two. It is the classic signal for a full strip and re-lay — but it says nothing about the quality of the slate, which can often be salvaged and re-laid.

Can the old slates be reused?

Frequently, and it is worth asking. Sound slates come off, go back on the most visible slopes with new fixings and new battens, and new material fills the shortfall on the least visible elevations. It costs more in labour and less in material than full replacement, and it keeps the weathered appearance that a designated street depends on.

Can I re-roof in concrete tile instead?

Think about weight before appearance. Concrete tiles are considerably heavier than natural slate, and a nineteenth-century roof structure was not designed to carry them — spread rafters, deflected purlins and pushed-out walls are all consequences seen in practice. On a designated address it also changes the appearance of the building and is generally resisted.

My house already has concrete tiles on an old structure. Is that a problem?

It is worth having looked at. Outcomes range from no visible effect to genuine structural distress, and the signs — rafters spread at the ridge, a dipping ridge line, purlins visibly deflected, or the tops of walls pushed outwards — are identifiable on inspection. Where a concrete roof is being replaced anyway, returning to a lighter covering is a structural improvement as well as a visual one.

Should I insulate while the roof is off?

It is the cheapest opportunity you will ever get, so the decision has to be made before the scaffold goes up. With the covering off, insulation can be installed over or between the rafters in the same operation, at a fraction of the cost of doing it later from inside and without consuming head height the same way. Whether it is worth it depends largely on whether the loft may ever be converted.

Why does my chimney breast keep getting damp?

Usually the stack rather than the breast. Failed flashing, cracked flaunching, open pointing and — on a disused stack — the absence of any ventilation to let it dry all let water into the flue, and it appears on the breast two floors below where it is attributed to something else. On a designated street, capping a disused stack with a vented cap is far preferable to removing it.

What does a refurbishment architect in Tottenham charge?

We publish fixed-fee packages rather than quoting a percentage before seeing the house, beginning with a survey and a written strategy credited against the design work if you proceed. On a roof we ask for a small area to be opened before any replace-or-repair conclusion, because the fixings and the battens decide it and neither is visible from the ground.

How much does a house refurbishment cost in Tottenham?

Fees for house refurbishments in Tottenham follow scope, consent complexity and whether freeholder or specialist input is required. Published packages start from a fixed fee once scope is clear; council, engineer and freeholder surveyor fees are usually separate. See our packages page for current fixed-fee bands — we confirm a fee only after the address and proposed work are understood.

Discuss a refurbishment in Tottenham

Send your Tottenham address, photographs of the roof from front and rear and of any internal damp, and a note of whether the covering is slate or concrete tile. We will advise whether this is a repair or a re-roof, whether the structure suits the covering it is carrying, and what insulation is worth doing while the roof is open.

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