Roof repair and replacement cost guide 2020
Roofs inevitably need repair and occasionally replacement – so why do we ignore them so? It’s the part of our homes that takes all the impact from the elements, birds and more besides and all the while it fearlessly keeps us dry and warm.
Clearly, they’re a pain to get to, but when things go wrong, you pay a heavy price for taking your roof for granted. That roof combination of sturdy substructure, insulation and protection and finally a surface cover that has to withstand all sorts of attack is essential not least in keeping the rain out. So how best to approach managing, repairing and replacing your roof?
Overview of roof repairs
The first you’ll know about a problem with your roof is when you find a leak.
A leak will most likely appear as brown staining on your ceiling. If left untended will eventually create a bubble in the ceiling plasterboard. This visible evidence of damage is not always directly under the failed roof tile itself. A hole will generally be found in the felt or membrane found fitted on the roof structure itself, below the battens and tiles.
Roofing membranes degrade over the years. The most common roof failure is a cracked tile, letting in penetrating rain. This water then finds its way under the tile and finally drips onto your ceiling. If you’ve boarded the floor in the loft space, it’s this boarding that will absorb the water. This often leads to delays in actually identifying that there’s a problem in the first place.
There are other symptoms of roof failure. The lead flashing, which is used to cover the joins between vertical walls and roofs, can be secured poorly. It can be prone to slippage over time and water can then find its way through gaps that appear. The rainwater management system that controls rain coming off your roof house might fail. Issues are that gutters can get blocked and plastic downpipes may pop out of their connections. Fascias and soffits covering the junctions of roofs and walls may also erode over time. If they are made of timber, they can deteriorate with harsh weather over the years and once weakened will need immediate repair.
All of these issues are very much repairable, the problem is that they are all challenging for DIYers. Roofs are, quite obviously, incredibly dangerous places to be working on and with all of the above, an experienced roofer, with the correct health & safety training, is essential.
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When should I replace my roof altogether?
If you have a severe underlying issue with your roof a patch repair to stop the odd leak will not suffice. The relatively high costs of continually repairing problems may mean that a comprehensive re-roofing is required.
Re-roofing can take one of two forms, a project where the existing rafters are found to be dry, stable, not rotting, and structurally sound. In this scenario, the felt, battens and tiles are replaced. The other re-roofing solution is a much more invasive full rebuild of the roof structure.
In most cases, the latter is only really an issue on properties many decades old and is often visible to the naked eye through bows and curves in the shape of the ridge or pitch.
How much does a roof replacement cost?
The more common type of roof replacement, the change of covering, is quite common and should be strongly considered after a visual inspection of the tiles. Concrete tiles installed in the period 1940-1980 may well now be subject to cracking and, if this is on a large scale, it’s usually wise to bite the bullet, rip them off and at the same time replace the membrane and battens. The cost of this job depends on what you intend to replace the old tiles with but typically costs in the range of £3,000 – £5,000. A full new roof structure, including all original timbers, insulation, membrane and tiles depends on the size of the house and the materials chosen but typically could cost between £10,000 – £30,000.
Specialist roof replacement roof by Fildes Roofing Ltd
How much does a flat roof repair or replacement cost?
The quality of flat roof construction has improved enormously over the past couple of decades, which is both good and bad news. It means that your old (pre-1990s) flat roof is likely to be at risk – the good news is that you’ll end up replacing it with something far superior that will in all likelihood last you for the foreseeable lifetime of the house itself.
Older flat roofs are more prone to suffering from leaks than pitched roofs. The reason is that rainwater has no natural place to escape too and the felt-and-gravel style roof seen on many a suburban extension is likely to be totally flat – while modern flat roofs are always built up with firrings, giving a 2-3˚ slope to allow water run-off. Couple that with the damage that burning sun, mosses and general wear and tear can inflict on a bit of usually stuck-down old felt – and you can see why they have a bad reputation.
In almost all cases the best option for the owner of a leaky flat roof is not to repair individual patches of decay but replace the whole structure. Most modern flat roofs are built as ‘warm’ roofs, meaning that the joists sit below a deck, on top of which sits a 100-150mm layer of rigid insulation and then a single ply rubberised membrane, or a similar GRP version. They’re UV resistant and expected to last for decades. Typical costs are around £100/m2.
Will I need planning permission for a roof repair or replacement?
You can repair or replace your roof under permitted development rights assuming there is no evidence of protected species being present, Any alterations project must be no more than 150mm from the original plane. If you are repairing or replacing less than 25% of your existing roof, building regulations approval will not be necessary. If, however, your project is more significant, you will require building control approval.
Who should repair or replace my roof?
Given the danger of working at heights and the skill required to do a job that lasts, it is essential to employ an experienced roofing contractor. Use Checkatrade to find someone in your area to give you professional advice.
Roof Repair Cost Calculator
Note:*The cost range(s) in our guides are estimated average costs based on current market research and input from our expert tradespeople. It’s entirely possible that on occasion various factors including scope of the project, quality of selected products, regional product cost and labour cost differences may mean that prices you actually find may be different. We aim to give a sensible ballpark estimate price for a quality job but prices are for general guidance only.
Roof Jargon Buster
The humble roof has a language all of its own – so when you’re talking to roofing specialists about repair and/or replacement, it’s good to have an idea of the key terms.
The highest part of the roof where two different slopes meet on a flat plane is called the ridge. Special tiles called ridge tiles provide a form of capping – curved or angled – to stop rain entering.
A hip is the same as a ridge, but on a lower, sloping part of the roof. Again, special hip tiles provide a capping between the two angled tiles.
A valley is the V-shape at the bottom of where two roof slopes meet.
The pitch is the angle of the roof slope. The taller the roof, the bigger the pitch. Most roofs tend to have a pitch between 30-45˚ – even modern ‘flat’ roofs tend to have a pitch of around 3˚. The steeper the pitch, the quicker the rain falls off – and in snow-bound countries shallower pitches require more support because of the heavier loading accumulated snow brings.
Steep pitch replacement roof by Fildes Roofing Ltd
The (usually) lead cover that overlaps the junction of a vertical wall, chimney or dormer with the roof itself, preventing water getting in the gap.
The solid bit of wall that is on the same level as the pitched roof is called the gable, or gable end.
A verge describes the edge of a sloping roof as it means a gable end.
The eaves are the underhanging element of where the roof meets the walls.
Soffits bridge the gap between the top of the wall and the underside of the roof.
Otherwise know and bargeboard, fascias provide a decorative solution in covering the point at which the wall and roof intersects – they also have a practical function in carrying the guttering.
Roofing is not recommended for a DIY project. Working at height brings inherent dangers, and without the proper safety equipment, scaffolding and procedures, you could seriously hurt yourself and others. We always recommend getting a professional roofer in to either make repairs to your roof or to replace it entirely. Our expert roofer Mike Fildes, owner of Fildes Roofing Ltd, offers his insights to getting your roof project underway.
Select a local Checkatrade vetted roofing company
Choose a roofing company local to your area, so if you need any further assistance at a later date, they will be easy to get hold of. Avoid giving work to roofers that come cold calling at your door, as they may just be passing through, and may vanish once the job is done.
Choose roofing specialists
Look for roofing contractors that specialise in the type of work you require. If you’re a business, choose an experienced commercial roofer. If you seek a flat roof, find a contractor specialising in flat roofs. If you demand specific work, such as a heritage roof or repairing of leaks, find out what credentials the roofing company has in these areas before making your decision.
High specification re-slating project by Fildes Roofing Ltd
Ensure you check the quality and date of feedback from customers
Many good roofing contractors get lots of their work through word of mouth, so go on Checkatrade to search for a vetted and checked local roofer with high average feedback scores. Ask to see examples of work and roofing projects already undertaken. Find out what accreditations the roofing company has. These are all examples that demonstrate high-quality standards.
High standard of professionalism
A quality roofer will provide you with a free consultation and quote, so you should never be charged for these. A good roofing company will also talk through all the different options with you for your roof, without putting you under any pressure to make a decision. Importantly, if the roofer turns up on time, answers and returns your calls, and does what they say they’re going to do, this is a positive indication of reliability and trustworthiness.
Don’t go for the cheapest quote
Getting value for money from any roofing company is essential, but a cheap quote alone shouldn’t be the determining factor. The important thing is the quality of workmanship and materials used because a cheap job poorly done using shoddy materials will prove a false economy in the long run.