A re-roof is the one moment when you can change the covering, and the choice is bigger than colour. Concrete tile, clay tile and natural slate behave differently on a roof, last for different lengths of time, suit different pitches and cost different amounts to supply and lay. Pick the wrong one and you may meet a Building Regulations question, a structural question or a planning question that the right choice would have avoided.
Many people start from the look of the house next door and work backwards. That is sensible, because matching what is already on the street is often what keeps a roof acceptable to the council, especially in a conservation area. But the matching has to be weighed against the pitch of your roof and the strength of its timbers.
This post compares the three coverings on the points that decide a re-roof around Farnborough and its neighbouring villages: published lifespans, minimum pitches, weight, cost as far as published guides give it, and the planning side. Figures are typical ranges from named sources, never promises, and the data sheet for the exact product always has the last word.
Years of service to expect from each
Published lifespans are typical ranges, and the guides do not always agree with each other. The table gives HomeBuilding & Renovating's figures for the coverings, with a note below where another maker or body differs.
| Covering | Typical life |
|---|---|
| Welsh slate | 100+ years |
| Spanish natural slate | 75 to 100 years |
| Reclaimed Welsh slate | 50 to 80 years |
| Clay tile | 60 to 80 years |
| Plain or Double Roman concrete tile | 40 to 50 years |
Where the published figures differ
For clay, Marley reports a BRE minimum of 60 years. That is a clay-only figure and does not carry across to the other coverings. For concrete, Marley gives around 60 years too, with a plain warning that this is no warranty on the tile, while HomeBuilding puts concrete at 40 to 50. A gap that wide between two published sources shows why no single figure tells you how much life remains in a particular roof.
What the covering is not
A tile outlasting its battens is common. The covering is one part of a roof, and the nails, battens, underlay and ridge fixings can fail while the tiles above are sound. Read a lifespan as the covering's own range, not as the life of the roof. Our answer on how long roof tiles last goes into the detail, and the pitched roofing page covers the coverings we lay.
Minimum pitch for each covering
A roof's pitch limits what can go on it. Each tile has a minimum angle below which its maker does not support it, because on a shallow slope the wind can drive rain up beneath the overlaps.
| Covering | Minimum pitch |
|---|---|
| Marley clay, Canterbury plain tile | 40° |
| Marley clay, Ashdowne plain tile | 35° |
| Marley clay, Lincoln pantile | 15° |
| Marley concrete, plain tile | 35° |
| Marley concrete, Double Roman | 22.5° (smooth) |
| Marley concrete, Wessex | 15° |
| Marley concrete, Mendip 12.5 | 12.5° |
| Natural slate | 20° (BS 5534, via Cupa) |
How to use the table
Start with the lowest figure that applies to your roof and work upwards, not the other way round. Cupa, a slate supplier, reads BS 5534 as putting the floor for natural slate at 20 degrees, and it says hooks are not for slopes under 25 degrees. Small plain clay tiles are laid with deep overlaps and need a steep roof. Interlocking concrete tiles and clay pantiles go far lower. If your roof is shallow, the choice may narrow to a few products before taste enters into it. A bungalow, an extension roof or the shallow slope over a porch is where this bites hardest, since those roofs are often built to a low angle.
The figures above are for the Marley products listed. Another maker will give different numbers, so go to the maker's data sheet for the very tile in question, and be wary of a quote that names a covering without naming the product. The pitch of the roof as built also needs measuring; it can differ from the drawings.
Weight, and when a change needs approval
The weight of the new covering matters more than people expect, because the roof timbers were designed to carry a particular load. Swapping a light covering for a heavy one without checking can overload them.
The 15 per cent test
The Planning Portal says Building Regulations approval is needed when a new covering makes the roof 15 per cent or more heavier than before. It lists a second trigger, which is a covering whose reaction to fire is markedly unlike the old one. Where weight is the issue, it recommends an engineer's or surveyor's look at the timbers before work begins.
Approved Document A, the structural guidance, words it a little differently and counts a rise in loading of over 15% as significant. The two are close, and either way the practical step is the same: get the weight per square metre of the old and the new covering, and ask a surveyor whether the timbers can take the difference.
Approval, not planning
A covering that is 15 per cent or more heavier brings a Building Regulations question, not a planning one. Planning permission and Building Regulations approval are separate systems.
What this means for the choice
Weights vary by product and the data sheet gives each one. If you move from a light tile to a heavier one, or from slate to concrete or back, ask for the weights to be compared on paper, and for the roof structure to be looked at.
What the published guides say about cost
Cost is where the three coverings diverge most, and the published figures are limited. We give what the guides say, with their names and dates.
Supply-only slate prices
HomeBuilding's supply-only rates are £72 a square metre for Spanish natural slate, £90 for reclaimed Welsh slate and £185 for Welsh slate. Those cover the product alone, before anyone fixes it to a roof.
A whole roof
HomeBuilding's worked example is a three-bedroom semi with 65 square metres of roof. With plain concrete tiles it puts the job between £10,000 and £15,000, with labour, scaffolding and insulation all in, and adds that in Welsh slate the same house could reach £18,000. MyJobQuote's typical figure for fitting a slate roof is around £7,800 (October 2026). Which? (November 2025) gives £7,000 to £21,000 for an entire new roof on an average three-bed house, ex VAT. These sources disagree widely, and that is a fair reflection of how much the house, the access and the covering change the figure.
What this says about choice
Slate costs more to buy than concrete tile, and it can take longer to lay, but its published life is longer. Reclaimed slate sits between the two on supply price, and it brings a look that suits older houses. Over a long period the dearer covering can be the cheaper one per year, so look at the cost over the life as well as at the first figure. These are typical UK ranges, not Fortis Roofing Farnborough prices; your written price follows the survey. Our change of roof tile type answer covers what is involved in switching.
Matching the street and the conservation area
What is on the neighbouring roofs shapes what a council will accept, and the stricter the setting, the more it matters.
Re-roofing a house is normally permitted development
Class C of the permitted development rules handles roof alterations to a dwellinghouse, and re-roofing counts, so a house can normally take a different covering without a planning application. Flats are different: a building containing flats has no permitted development rights. A listed house keeps those rights but also needs listed building consent for any work that changes its character.
Conservation areas
Rushmoor has nine designated conservation areas, among them South Farnborough (designated 1987, revised 2025), Farnborough Street (2025), Farnborough Hill (2025) and St Michael's Abbey (1977). If your house is in one, tell the survey; the council's planning team can advise on whether the covering you have in mind suits the area. Article 4 directions can withdraw permitted development rights, and the roof-relevant one in Rushmoor is Aldershot's Cargate direction, which covers chimneys and flues.
Basingstoke and Deane's wording
For its four town-centre Article 4 areas, Basingstoke and Deane Borough Council wants original Welsh slate and clay roofs retained, and it expects concrete tiles or artificial slates to be turned down. That is one council's position for its own areas only, but it shows what a conservation team may expect to see. Our answer on matching roof tiles shows how matching is done.
Working through the choice for your roof
With those points in hand, a simple sequence settles most re-roof choices. Start from the facts of the roof and let the preferences come second.
Step one: the pitch
Measure or have measured the pitch of each slope. That narrows the field straight away, because a shallow slope rules out plain clay and some slates, and a steep one opens everything.
Step two: what is there now
The existing covering is the starting point for weight and for planning. If you are keeping to the same material, the weight question disappears. If you are changing, the 15 per cent test comes in, together with any conservation area wording.
Step three: the setting
If the house is on the statutory list, stands in a conservation area or belongs to a matching terrace, ask what the council expects before you order. Matching a terrace keeps the street consistent and avoids a refusal, and it is usually the simplest route through the planning team.
Step four: the budget over time
Compare the supply and laying cost with the published life. A longer-lived covering costs more at the outset. Think about how long you will keep the house: one you will live in for decades justifies a different choice from one you plan to sell soon.
Step five: the survey
A survey records the pitch, the structure and the state of the timbers and shows you photographs. Fitting the choice to the roof and not the other way round is the point of it. The written price follows, and covers the whole job.
