Most gutters hang from brackets on the fascia. Concrete gutters do not. They are moulded sections that sit on or in the wall head, at the foot of the roof slope, and they carry the rain to a downpipe through an outlet at one end. They are found on some older homes and outbuildings, and they are a different problem from the plastic or metal gutters a roofer deals with every day. The key difference is that you cannot unclip one and put a new one on.
The concrete is rarely what fails. The trouble is the joints between the sections, the outlets where the water leaves and the lining or coating inside the channel. Water then gets into the wall or the roof edge, where it stays out of sight. By the time a damp patch or a rotten timber shows, it can have been going on for years.
This guide explains what concrete gutters are, why they leak, how a repair or a lining works, what replacement involves and what a national average cost figure looks like. It also covers the asbestos question that can apply to old rainwater goods. Our guttering, soffits and fascias hub covers the other materials.
What a concrete gutter is and how it sits
A concrete gutter is a channel cast in concrete, made in lengths that are laid end to end along the eaves. The profile is usually a shallow U or a box shape, deep enough to carry a good flow of water from the roof.
Built into the building
Instead of hanging off the fascia, the gutter often rests on the wall head, with the lowest courses of the roof covering overhanging it. In some designs it is bedded into the brickwork. The gutter therefore forms part of the structure at the edge of the roof. Water that escapes does not drip harmlessly onto the ground. It goes into the masonry, the roof timbers or the ceiling space.
Joints and outlets
Each length meets the next at a joint, which is sealed with mortar, mastic or a flexible compound. At one point a hole is formed for the outlet, which connects to a downpipe through a short spigot. These are the weak points, because every joint has to cope with movement and every outlet is the place where the flow concentrates.
Linings
Many concrete gutters carry a waterproof lining on the inside, such as bitumen, a paint or a liquid-applied coating. The lining stops water soaking into the concrete and makes the joints watertight. When the lining cracks or peels, the whole channel starts to leak.
A survey starts by working out which of these parts has failed. Without that, money is spent on a new lining over a joint that is the real cause, or on a new joint seal over a lining that has already failed.
Why concrete gutters leak
The common leaks follow from how the gutter is built, and they usually announce themselves with damp in the same places.
Failed joints
Sealant between sections dries, shrinks and splits as the building moves with the seasons. Water then runs through the open joint, down the face of the wall or into the cavity. Algae stains below a joint, or a dark streak on the brickwork, are the typical signs.
Cracked or worn lining
Old linings crack with frost, age and foot traffic on the gutter during maintenance. Once the lining has failed, water soaks the concrete, which is porous. It can freeze and flake the surface, and eventually the steel reinforcement inside can rust and expand, cracking the concrete from within.
Blocked outlets and standing water
Leaves, moss and silt settle in a flat gutter. A blocked outlet leaves the channel full, so water overflows the front or soaks through any weakness. Water that never drains also ages the lining, and a gutter that stays full through winter may also freeze and lift the surface. Our answer on overflowing gutters explains how blockages arise.
Lost fall
If a section has settled, the channel no longer slopes towards the outlet and water collects. A pool in a concrete gutter is a slow leak waiting to happen, because the lining under it is always wet. Even a slight dip can be enough to hold a puddle that never clears.
Relining a concrete gutter
When the concrete is sound and the problem is the lining and joints, relining is the lighter-touch fix.
What it involves
The gutter is cleaned right out, loose material and old lining are removed and the surface is prepared. Cracks and spalled areas are repaired with a suitable mortar. Joints are opened up and resealed. A new waterproof lining is then applied, which might be a liquid-applied membrane, a GRP or fibreglass lining or a sheet system, depending on the shape and the condition. Outlets are renewed or sealed in.
Advantages
It avoids taking the gutter off the building, which means no heavy lifting, less disruption to the roof edge and a lower cost than replacement. If the concrete is in good order, a well-made lining can restore the gutter for a long time.
Limits
A lining cannot fix a gutter that has lost its fall, or one with cracked or rusted sections. It sits on the surface, so the base must be sound and dry. Applied over damp or loose concrete, it will fail early. Our guide to GRP fibreglass roofs explains the material, which behaves in much the same way.
Checking it first
The sensible test is to probe the concrete for softness, look for exposed or rusting steel and check the fall with a level before deciding to reline. A bubble of water poured in at the high end, and watched as it runs, shows a lot about the fall. If the survey finds the base is sound, relining is a fair and proportionate answer.
When replacement is the better answer
Sometimes the gutter has gone too far, and the sound advice is to take it out.
Signs that point to replacement
Concrete that is cracked through, crumbling at the edges or showing rusted reinforcement. A gutter that has dropped or tilted so that the fall is wrong along its length. Sections that have shifted apart so that joints cannot be closed. Repeated failures of new linings in the same places.
What replacement involves
The old sections are removed, which is heavy work needing scaffold and sometimes lifting gear. The wall head and roof edge behind are checked for damp and rot and repaired. A new gutter is then fitted: often a modern box or lined gutter, sometimes a conventional gutter on brackets with a new fascia, if the building allows it. Our guide to gutter replacement cost sets out the published ranges for other types.
Scaffold and access
Taking out concrete sections is not a ladder job. If scaffold stands on the public highway, the highway authority licenses it, which for Andover is Hampshire County Council, and the scaffolding company applies on behalf of its customer. The cost is part of the written price.
Damage behind
Replacement is often the moment hidden rot is found in the wall plate or the rafter ends. We take photos of what we find and tell you before extra work is done, so the final bill holds no surprises, and you see the decayed timber with your own eyes before you agree to renew it.
What replacement costs, as a published average
Because concrete gutter work depends on the length, the height and the condition of the roof edge, any published figure is only a starting point.
The MyJobQuote average
MyJobQuote gives an average of £2,400 for concrete gutter replacement. The page is dated January 2026, so prices may have moved since then, and it is best to treat it as a guide to scale and not a current price. It is a national average and not a price for your house.
How it compares
The same site puts a standard gutter replacement at around £1,000 to £1,600 (Oct 2026), so a concrete gutter costs noticeably more because of the weight, the scaffold and the repairs to the roof edge that usually come with it. That is a general comparison, and a short run on a low building may cost less. A tall house with a long run, where the gutter has to be lifted out in heavy pieces, can cost considerably more.
What moves the price
Length of the run, the height of the eaves, whether the sections can be lifted out in one piece or must be broken out, the state of the wall head and rafter ends, and what replaces the gutter. A relining job costs less than a full replacement but depends on the base being sound.
The written price
The written quote follows the survey, and it states one total for the route chosen, scaffold included. Citizens Advice recommends collecting at least 3 written quotes, and each trader should be shown the same photos, so all are pricing the same gutter. A low figure that leaves out the scaffold or the wall head repair is not a saving.
Asbestos cement in old rainwater goods
Older rainwater goods can contain asbestos, and the HSE gives specific guidance on handling it.
Where it is found
The HSE names rainwater goods among asbestos cement products, alongside roof sheeting. A concrete-looking gutter on an older building might in fact be asbestos cement, which is a pressed mix of cement and asbestos fibre. You cannot always tell by sight.
The rules
Under the HSE's classification, taking asbestos cement down with care, in whole pieces, counts as non-licensed work, weathering included. Work that would smash or crumble it becomes notifiable non-licensed work, which changes who has to be told. Two layers of wrapping and a label go on the waste, which leaves on a consignment note and never in an open skip.
Before any work
If the building is old enough for the gutter to be a question, have the material identified before it is cut, drilled or broken. A house from before 2000, whether built or refurbished then, is one where the HSE says to presume asbestos until shown otherwise. Our guide to asbestos soffits explains the process and the testing step.
Our approach
We raise this at the survey, ahead of any price, and note on the report which parts of the gutter we think need identifying. We do not break up or drill a gutter we cannot identify, and the written total makes clear how any test and the waste will be handled.
