Essential Roof Guide: Safeguarding Your Home from Top to Bottom
When I'm carrying out home surveys, here are some tips & info I'd like to share about roofing. The roof is mainstay of every home, it’s important to check how sound the roof is before you seriously consider buying a property. If the roof is pitched, look out for missing, slipped or damaged slates or tiles. You should be able to see lead or similar material around protrusions, chimneys, vents and skylights through the roof. These are called flashings and if you notice any sagging, damage or bowed areas, seek professional advice. On flat roofs, you should check that rainwater outlets are not blocked and the roof is free draining.
Roof interiors
Internally, look out for damaged, damp or fraying sarking felt. Buildings prior to the 1930’s had no secondary layer of protection under the slates/tiles to the pitched roof. The use of mortar “torching” on the underside of tiles or slates to keep them in place and to prevent strong winds from getting under the tiles and lifting them was common. The torching held them in place before nibs were added to secure them onto wooden battens. If the material is brittle, it can crack and drop off.
Roofing felt was first introduced on a regular basis in the 1930s, when it generally consisted of thin building paper. Later the use of a bitumen based felt became widespread due to its superior waterproofing properties and durability. This evolution marked a significant improvement in roofing technology, as bitumen felt provided an effective moisture barrier that enhanced the longevity and integrity of roof structures. However, Bituminous felt flat roofs can have a limited life, often 10 to 15 years from installation. They therefore require periodic replacement, and often intermediate maintenance, so should be checked regularly. They can fail suddenly but more usually water seeps in gradually, eventually resulting in damp penetration noticeable internally. On stripping the covering, the decking is also often found to be defective, particularly if chipboard has been used.
Installation-pitched roofs
Things to look out for are incorrect laps on tiles that can allow ingress of water which will damage your roof and roof space. Nails placed in the wrong place, or too few used to hold down the tiles, can result in tiles slipping and breaking, particularly during bad weather.
Guttering installed incorrectly can misdirect water to areas where it can cause damage.
Roof inspections, maintenance and decluttering
I recommend that Homeowners should carry out a twice-yearly roof inspection particularly in Autumn to remove debris and in the spring to rectify any weather damage. Carefully clear away any debris from your roof, including leaves, branches, moss, algae and other organic matter. Accumulated debris can trap moisture and cause rot and mould.
Trim overhanging branches that can scrape and damage your roof and provide a pathway for pests like squirrels to access your home.
After a rainstorm, check your attic or crawl space for signs of water leaks, stains or damp insulation materials. Address any leaks promptly to prevent further damage. Replace any damaged slates or tiles after a storm.
Consider scheduling an annual or bi-annual professional roof inspection, especially if you have a number of roof pitches that cannot be inspected from the ground. This is more common on older and larger houses.
Roofing experts can identify issues that may not be visible during a visual inspection and recommend necessary repairs or maintenance. Additional inspections should be carried out in the event of extreme weather conditions, vandalism, and construction work on or adjacent to the roof, including the installation of equipment (e.g. HAV or Air-conditioning plant, telecoms equipment or solar power generation modules).
Also, where there are many trees around the roof, or it is in a particularly leafy area, more frequent inspections may be necessary.
Guttering and blocked drains
If downpipes and gutters are blocked with rubbish it can cause water to overflow into the fabric of the building leading to internal damp, which can cause damage to ceilings, windows, woodwork and walls. Ensure gratings over outlets are clear and clean gutters and downspouts thoroughly at the start of autumn and spring. Trapped water can get up under the roof coating, causing damage to the edge of your roof's surface and the underlying materials.
Wood fascia damage
Check the fascia board for signs of damage. The fascia is a large wooden covering near the bottom of your roof that protects the lower part of your home from rain damage. Large clogs in gutters can cause water to penetrate your fascia board which can cause it to rot, fall off or be severely damaged.
Flashing
Your roof flashing provides protection at joints and without which water can effectively pour straight into your home. Some mineral surface bitumen membranes can shed excess minerals for a while after installation and will accumulate around gutters and around outlets. This should be cleared away. Renew mortar or mastic pointing at the top of upstands or counter flashings. Flashing is meant to protect valleys and protrusions like vents and chimneys so it can cause water to leak into your home if not fitted properly.
A brief history of roof types and roofing materials
Pitched roofs have changed over the years. Traditionally known as “cut” roofs, they comprise separate rafters and purlins. This type of roof is easy to adapt and change.
Pitched roof styles
Thatched roofs
Thatched roofs have been around for hundreds of years. This was because the materials needed for a thatch roof were plentiful and accessible to everyone. In some parts of the UK, until the 1800s, this was the only material available for roofs because the commercial production of materials such as slate had not yet begun.
Slate roofs
Slate roofing tiles were originally used by the Romans until the 5th century and then largely forgotten until the 11th century, when the Normans brought with them a new architectural style.
Pitch Roof Coverings
Slate roofs began being used on private homes in the UK in around 1300. Particularly in North Wales and England. This was because slate was expensive and difficult to transport, so it was only used on houses that were near slate quarries.
Large-scale slate quarrying began predominantly in North Wales in 1782, which was responsible for 92% of slate production at this time. The introduction of railway lines and the removal of slate-duty meant that it was finally able to be commercialised and transported across Britain and gained popularity in the Victorian era for working class homes. By the 1900s, slate production had slowed down because the demand was no longer there.
Clay
Similarly to slate, clay tiles were first introduced to the UK by the Romans around 100 BC. Makers would pull the clay out of lakes and rivers and mould it into the shape of a tile and bake it in a kiln to be used on their shelters. They were also only available in the region they were produced because of the difficulty to transport.
Clay became popular in the 1600s when rebuilding began after The Great Fire Of London. It was taken from the Thames to rebuild homes after the blaze ripped across the city. However, clay was susceptible to warping, frost damage and leaking and so slate roofs became much more desirable.
Improvement in production and the ability to mass-produce identical clay tiles has made clay more popular in recent times. It now offers durability against the wet weather conditions in the UK as well as durability and fire resistance.
Concrete Tiles
During the 20th century, concrete rose dramatically as the most popular roofing material. Tiles made from concrete are almost always uniform and do not suffer from issues with frost or leaks. However, as of late, concrete is a heavy material and has fallen out of fashion as a roofing choice. Problems can occur with overloading of the roof structure causing deflection if concrete tiles have been used in place of lighter slate or clay tiles. If you have concerns seek professional advice.
Trussed roofs
In the 1960s, trussed rafter roofs became popular. These are engineered roofs and the trusses are delivered to site ready-made and hoisted into place. They are more difficult to adapt than a traditional roof of rafters and purlins as any changes to the trusses need to be structurally designed.
Flat roofs
Flat roofs have been around for centuries but were widely adopted in the UK after the Second World War when they were seen as a cheaper alternative to pitched roofs. The most common roof covering was two or more built up layers of bituminous felt as their weather proofing, but in more modern times the use of other roofing materials, such as rubber, fibreglass and other synthetic-based materials & membranes began to offer far superior waterproofing than previous other materials and popularity soared.
What types of insulation would you recommend?
The insulation you choose for your loft will depend largely on the use you’re intending to make of the space. As well as any specific challenges the shape of your loft poses. The most common types are rock, glass or mineral fibre. These are the easiest to fit yourself. Blown insulation is ideal for hard to get to places but does not offer a full solution for a draught loft. It also has to be installed by a professional. Looser fill insulation such as cork granules, mineral wool or paper is good for topping up existing insulation but it’s not very secure and can be messy to fit.
What is the most difficult type of roof to repair?
Pitched roofs are more expensive to repair as scaffolding is required for access. Flat roofs are easier to access, although some scaffolding will be required, and can easily be patched repaired. Specialist roofs should be inspected in accordance with the designer’s original inspection plan. For listed buildings, you should consult with the local authority Conservation officer for advice. There may be restrictions on the materials that can be used and formal Listed Building Consent may be required.
What are the most durable roofing materials?
How much of a problem is asbestos these days. Can you tell which types of building may have asbestos in the roof?
Any building built before 2000 may have asbestos. if you have any doubt, contact a licensed asbestos contractor and ask for a quote to survey the roof.
How to install a green roof
In general, a replacement roof or retrofit does not need planning permission before it can be carried out and installed. Having said that, it is always a good idea to check with your local council before you go ahead and carry out any major external renovation, particularly if you live in a conservation area or own a listed building. It might also be polite to run your plans by your neighbours if you are on good terms with them.
While there are no specific building regulations relating to green roofs, there may be issues concerning load capacity, fire prevention or the disposal of water from the surface of the installation. Building regulation approval is needed under a wide range of circumstances including:
When you construct a new building.
When you extend or alter an existing building (this may well be the issue where a green roof is most pertinent).
If you convert a loft space or replace windows.
Installing services and fittings into a building such as hot water cylinders or fuel burning appliances.
If you are building a green roof then you may need to fill in a Building Regulation Approval Notice application which means someone approved by the council will need to inspect your property to make sure it is suitable for a green roof. If your installer is on board with the Green Roof Code then they will be able to talk you through the process.
How do you check roof timbers for infestation?
The first and most obvious sign of active woodworm is frass. Frass is a fine, dust-like substance that looks a bit like sawdust. Frass is the discarded, chewed timber the adult beetle creates when exiting the wood, it is commonly found in and around exit holes where active infestation has occurred. The length of the larval stage varies considerably and can extend over several years. In active infestations, new generations enter the wood each year after egg-laying, so only a proportion of the total population emerges to the surface as adults in any one year generally in the spring. If you notice signs of frass or suspect woodworm in your timbers, it is crucial to contact a pest control specialist immediately to assess and address the issue.
What should you do about bees, wasps, rats or bats?
Bees and Wasps: Bees and wasps can be a hazard, especially if they nest in or near your home. Avoid removing bees yourself to prevent stings; instead, contact a professional beekeeper or a pest management team who are equipped to safely relocate the hive. For wasps, locate the nest carefully and use a commercial wasp spray or call pest control to handle severe infestations.
Rats: Roof rats, or black rats, often nest in the upper parts of buildings and can damage wiring and structural materials, posing fire risks and health hazards due to contamination. If you notice signs like gnawed cables, it’s crucial to contact a professional pest control service to manage the infestation effectively.
Bats: British bats, protected by law, use roofs for roosting and are harmless to humans. If bats are present, avoid disturbing them and consult the National Bat Helpline or a conservation expert for advice on managing and coexisting with bat roosts.
Other Animals: Mice, squirrels, and birds can also invade roof spaces, causing damage through gnawing and nesting. Birds' droppings can degrade roofing materials and pose health risks. For humane removal and prevention, consult with a licensed pest control expert and follow guidelines from the British Pest Control Association (BPCA) for best practices in wildlife management.
The Risks of Penetrating Damp in Roofing
Penetrating damp in roofing can lead to serious issues such as structural damage, insulation degradation, and potential health risks due to mold. It typically occurs when water infiltrates through faults in the roof like damaged tiles or inadequate flashing.
To prevent these problems, it’s crucial to perform regular roof inspections to ensure that all components are intact and functioning properly. Early detection and repairs can help maintain the roof’s integrity and prevent extensive damage to your property. For expert assessment and maintenance, consider consulting a professional roofing specialist.
If you are buying a residential property in London and the South East, the survey includes a professional property inspection of its roofing condition, RM Surveyors offers a comprehensive range of services tailored to ensure your roof is secure and well-maintained as part of a RICS Level 2 or 3 Home Survey.
As a residential chartered surveyor and RICS registered property valuer with over 20 years of real estate experience across London and the southeast, I am well-equipped to provide detailed RICS Surveys.
Understanding the critical role a well-maintained roof plays in the safety and longevity of your home, I am committed to simplifying the inspection process and helping homebuyers protect their investments. Whether it involves identifying potential risks, providing maintenance solutions, or recommending a roofing specialist, my goal is to help you make informed decisions.
If you're in need of top-notch drone photography, I highly recommend Matt Shearing Drone Photography - covering London and East Sussex. Specialising in detailed aerial inspections, Matt provides a unique perspective that significantly enhances the accuracy and thoroughness of roofing inspections and other property surveys.
Contact me today at roo@rmsurveyors.co.uk or by phone on 07957606886 for an informal, confidential, and no-obligation conversation about a RICS Level 2 and 3 Home Survey.