When a roof comes off, the covering is the one big decision left to you. Concrete tiles, clay tiles and natural slate all keep the rain out. They differ in weight, in the pitch they need, in how long published sources say they last and in how they look from the pavement.
It is tempting to look for a ranking, but the choice is closer to a fit test. A covering that suits a steep Victorian terrace may be wrong for a shallow bungalow roof, and a lovely heavy tile can push a straightforward re-roof into a job that needs Building Regulations approval and a structural check.
This guide takes the three coverings against the questions that settle the matter. How does each weigh against what is on the roof now? How steep must the slope be? How long is it likely to last? Does your street or your council expect a particular material? And what changes when the new covering is heavier?
None of this replaces a survey. Once we have seen the rafters, measured the pitch and identified the old covering, we can say which options are open. You get one written total for whichever option you pick.
Where each covering earns its place
Think of the three coverings as three different bargains rather than three grades of the same thing. Each suits some roofs and some budgets, and none of them wins on every roof.
Concrete tiles
Concrete tiles are cast, and they come in many profiles, from small plain tiles that imitate clay to large interlocking tiles that cover a lot of roof in each piece. They are the usual starting point when the budget matters and the street has no strong rule about materials.
Clay tiles
Clay is fired rather than cast, and it ages in a way that suits older houses. Plain clay tiles give the fine, small-scale texture of old cottages. Pantiles, the curved clay profile, give a rolling line along the slope. Either is a choice for how the roof looks as much as for how it performs.
Natural slate
Slate is split rock. It is thin and flat and sits in neat, narrow courses, which suits period terraces and farmhouses. It also carries the longest published lifespans, which counts if you plan to stay put for a long while, and it holds its character as it weathers.
Each has a cheaper look-alike, such as artificial slate or fibre cement. HomeBuilding gives fibre cement tiles a typical life of 30 to 40 years (Sep 2025), well short of the natural products. Our slate roofing page covers that material in more depth.
So the useful question is not which material is nicest in the abstract. It is which one your roof, your budget and your road allow. The next sections take those limits one at a time, starting with the one people forget: the weight on the frame.
Weight, and what the rafters can take
Every covering sits on the same timber frame, so weight is where a handsome choice can run into trouble. A roof built for light concrete tiles may not have been designed for a heavier clay or stone alternative, and the timbers may have aged since the house went up.
The Planning Portal sets a clear marker. A covering heavier by 15 per cent or more triggers approval under the Building Regulations, and the portal suggests an engineer or surveyor assesses the frame first. Approved Document A, the structural guidance, frames its own test as an increase of more than 15 per cent in the load. Either way, a heavier tile is a structural question first and a style question second.
Where the weight figure comes from
We do not guess. The maker's data sheet gives the laid weight of each tile or slate per square metre, and we set that against what comes off. That comparison depends on identifying the old covering properly, which is why the survey includes a close look from the scaffold or the loft.
What the frame tells us
Sagging rafters, visible dips along the slope, a bowed ridge or split purlins, the horizontal timbers that carry the middle of a slope, all suggest a frame already working hard. In that case a lighter covering may be the sensible route even when a heavier one is your preference.
If the numbers say heavier and the frame looks sound, the structural check can be a short job. If the frame shows distress, you hear it before any covering is ordered, and the conversation moves to the repair of the timbers first.
Minimum pitch is a hard limit
Pitch is the angle of the slope. Each tile and slate type has a lowest workable angle, under which wind-driven rain can be forced back up beneath the laps, and the manufacturers publish it. Putting a covering on a roof flatter than its minimum is the quickest route to a leak, whatever the fixings.
Clay
Marley lists minimum pitches for its clay ranges: Canterbury 40 degrees, Ashdowne 35, Hawkins 30, Acme Single Camber 30, and the Lincoln pantile 15 degrees. The spread is wide, which is why the named product matters more than the word clay.
Concrete
Marley's concrete list starts at 12.5 degrees for Mendip 12.5, then 15 for Mendip and Wessex, 17.5 for Edgemere, 22.5 for Double Roman and 25 for Anglia, rising to 35 degrees for its concrete plain tile. Some of those figures apply to the smooth versions of a tile only, so read the data sheet of the specific product you plan to use.
Natural slate
BS 5534 indicates a minimum of 20 degrees for natural slate. Cupa adds a limit of its own: avoid hook fixings on any slope under 25 degrees.
This is why a shallow bungalow roof, or a lean-to over an extension, often points to one of the low-pitch concrete or pantile profiles rather than a plain tile or a slate. We measure the angle at survey stage, so any options we put forward fit the roof you actually have, and the data sheet for the product we propose goes with the price, so you can read the limit for yourself rather than take our word for it.
How long each covering typically lasts
Lifespans are published as typical ranges and never as promises. A warranty period is not a lifespan, and a well-chosen roof with poor fixings or neglected gutters can age early. Treat the figures below as a guide to how the products compare, nothing more.
Slate
HomeBuilding gives Welsh slate 100 years or more and Spanish natural slate 75 to 100 years, with reclaimed Welsh slate at 50 to 80 years (supply-only guide, Sep 2025). Those are the longest figures in the published tables.
Clay
HomeBuilding gives clay tiles 60 to 80 years. Marley reports a BRE minimum life expectancy of 60 years, a figure that belongs to clay alone and cannot be carried over to other tiles.
Concrete
Here the two sources disagree, so we name both. Marley expects its roof tiles to reach around 60 years and adds that the number says nothing certain about any single roof. HomeBuilding rates plain concrete and Double Roman tiles at 40 to 50 years. If you are planning around the lifespan, plan against the lower figure.
Why this shapes the choice
A longer-lasting covering costs more at the start, and the benefit only appears if you stay in the house long enough to collect it. If you are selling within a few years, whoever surveys the house for a buyer will look for a sound roof and tidy paperwork. If you expect to stay for decades, the gap between the ranges is worth weighing against the price difference, because a covering that outlasts you saves a second re-roof. Our new roof cost guide shows what the published figures look like.
What your street and your council expect
A covering that is right on paper can still be wrong for the road. Roof material is a large part of how a house reads from the street, and councils protect that more firmly in some places than in others.
Matching what is there
Where a terrace or a row of cottages shares one covering, a single concrete roof stands out for decades. Choosing like for like keeps the group together, and it tends to make a future sale simpler too. Where your neighbours have already changed theirs, there may be little left to match.
Conservation areas and Article 4
Re-covering a house is dealt with under Class C of the permitted development rules, the class for other alterations to a dwellinghouse roof. Class C carries no conservation area exclusion, so planning permission is not normally the obstacle. A flat is outside permitted development altogether. An Article 4 direction, which withdraws specified rights across a defined area, can change the position.
Basingstoke and Deane, for one, has published roof wording. Its direction reaches four conservation areas in Basingstoke itself, taking in the centre and the Fairfields, South View and Brookvale West areas, and asks that Welsh slate and clay roof tiles be kept, calling concrete tiles or artificial slates unlikely to be acceptable. For any other council, ask its planning team whether a direction applies to your address. For Andover, Test Valley Borough Council's planning team can answer, and a note with your address is a quick way to find out.
Our guide to re-roofing in a conservation area walks through the consent route in order.
When a heavier covering needs approval
Swapping a light covering for a heavier one is the change most likely to lift a re-roof out of the routine. There are two separate questions, and they are easy to confuse.
Planning
On a house, a change of covering usually falls within permitted development, so the planning team only comes into it when the building is a flat, is listed or sits under an Article 4 direction. Listed houses keep their permitted development rights but also need listed building consent for work that affects their character.
Building Regulations
A covering heavier by 15 per cent or more brings in approval and a structural check. So does a covering that would behave in a fire very differently from the one it replaces. Weight is a Building Regulations matter, not a planning one.
Where the weight is similar, the Planning Portal test applies: the work normally needs no application while it touches under 25 per cent of the building envelope and under 50 per cent of the roof. Replacing the whole covering sits well beyond that line, so we confirm the route with your building control body at the outset. For Test Valley addresses that means asking Test Valley Borough Council who handles it.
In practice it comes to this. Like for like, check the paperwork. Heavier, get the structure checked before anything is ordered. Both steps happen at the start of the job, before a single tile is ordered, and the outcome goes into the single written price.
If you are weighing a partial job instead, see partial roof replacement, and the roof replacement overview for the whole picture.
