Signs you need a full roof replacement
Age is the most reliable indicator. Concrete tile roofs over 40-50 years old, felt flat roofs over 20 years old, and slated roofs showing widespread nail sickness are all strong candidates for replacement. Nail sickness occurs when the copper or zinc fixing nails corrode over decades and lose their grip: slates begin to slip across the roof rather than in isolated spots, and the problem accelerates once it begins.
Other signs that replacement is warranted: multiple leaks appearing in different areas simultaneously (suggesting widespread underlay failure rather than a single point failure), felt underlay visible and perishing from inside the attic, structural movement visible from inside (a sagging ridge or bowing rafters indicating the structure beneath has been compromised by long-term water ingress), or a history of repeated patching in the same areas without lasting result. A professional roof survey, costing EUR 150-300, is money well spent before committing to replacement expenditure. An experienced roofer or structural surveyor can assess the condition of the covering, underlay, battens and structure from both above and inside the attic and give you an objective view of the remaining lifespan.
Choosing roofing materials
Slate
Natural slate offers the best long-term value for Irish homes. Lifespan of 80-150 years means a slate roof replaced today may still be in service in 2100. It is the most appropriate material for period and Victorian properties, conservation areas and any building in a historic streetscape. The higher upfront cost compared to concrete tile is offset by a much longer replacement cycle and the fact that natural slate can be salvaged and reused.
Concrete interlocking tile
Concrete interlocking tile is well suited to post-1950s housing, 1970s and 1980s housing estates and modern extensions. It is lower cost than slate, faster to install, and readily available in a wide range of profiles and colours. Lifespan of 40-60 years with good maintenance makes it a practical choice where budget is a primary consideration.
Matching existing style
If you are on a street or estate where neighbouring houses have a consistent roof type, matching it supports kerb appeal and is less likely to attract planning scrutiny. Replacing a concrete tile roof with natural slate is generally exempt development under Irish planning regulations, but if the roof form or structure is also changing, it is worth checking with your local authority. Any doubt about whether planning permission is required should be resolved before work starts, not after.
Scaffold and access
All full roof replacements require scaffold. This is not optional: it is a legal requirement under Irish health and safety legislation (the Safety, Health and Welfare at Work (Construction) Regulations), and any contractor who proposes to do a full re-roof without scaffold is operating outside the law and without insurance cover. Do not agree to work without scaffold regardless of how the cost saving is presented.
Scaffold for a standard semi-detached house typically costs EUR 800-2,000 depending on house size, height and how long it needs to remain in place. Most roofers include scaffold in their quote, but this must be confirmed in writing before work starts: some quotes exclude scaffold and add it as a separate line item, making the initial figure look more attractive. Scaffold is typically erected the day before work begins and removed one to two days after completion, meaning it is usually in place for two to three weeks total for a standard re-roof.
What to expect during the work
Day one: scaffold erected. Day two: stripping begins, the existing covering removed down to the rafters or deck. New breathable sarking felt is then laid from eaves to ridge, overlapping at each course. New treated timber battens are fixed over the felt at the correct gauge for the tile or slate being used. Slates or tiles are then laid from the eaves up, with each course overlapping the one below.
For a standard three-bedroom semi-detached in Dublin or Cork, a full re-roof typically takes five to seven working days from stripping to completion of ridge, valleys and flashings. Scaffold comes down one to two days after the roofer signs off the job. Expect noise during working hours: stripping and nailing is loud and unavoidable. Access to the attic will be limited or impossible while work is ongoing. The interior of the house is not affected and you can remain in residence throughout.
SEAI grants and energy upgrades
A full roof replacement is the optimal time to upgrade attic insulation, as the scaffold is already in place and the attic is accessible. The SEAI Better Energy Warmer Homes scheme provides free insulation upgrades for qualifying homeowners (those on certain social welfare payments or with a household income below EUR 30,000). Under the scheme, 300mm of mineral wool insulation is typically installed to the attic floor at no cost to the homeowner.
The SEAI Home Energy Upgrade scheme (formerly the Better Energy Homes scheme) covers attic insulation as part of a broader whole-house upgrade, with grants of up to EUR 1,500 available for attic insulation alone. Both schemes require a registered SEAI contractor to carry out the insulation work. Check eligibility at seai.ie, and find a registered insulation contractor to line up alongside your re-roofing, coordinating both jobs together saves significant disruption while the attic is already open.
A new, sound roof is also the ideal base for roof-mounted solar, which carries its own SEAI grant. If solar is on your radar, it is worth talking to solar PV installers before the scaffold comes down, mounting panels while the roof is being worked on is cleaner and cheaper than a separate visit later.
Under Part L of the Irish Building Regulations, when more than 25% of the roof covering is replaced, the thermal performance of the roof must be upgraded to meet current standards. In practice, this means that for most full re-roofs, attic insulation must be upgraded to at least 300mm depth as part of the project. Your roofer should be aware of this requirement; if they are not, it is worth raising it before work begins.
Questions to ask your roofer before work starts
Before signing any quote or paying any deposit, get clear written answers to these questions: Are you fully insured, including public liability cover of at least EUR 2 million? Will you provide a written, itemised quote specifying materials by brand and specification? Is VAT included in the price? Will scaffold be erected and is it included in the quote? What is the payment schedule (avoid paying more than 30% upfront for any residential roofing job)? What guarantee do you offer on workmanship, and is it in writing? Are you a member of CIRI (Construction Industry Register Ireland)?
A confident, professional roofer will have no difficulty answering every one of these questions clearly and promptly. Hesitation on insurance or VAT, reluctance to provide a written contract, or pressure to agree a start date before a written quote is provided are all warning signs that deserve serious consideration before any money changes hands.