How often should a roof be replaced?

How often should a roof be replaced?

Roof replacement varies according to a number of factors such as the age and condition of roofing materials used on the roof, the exposure of the roof to the weather and the construction of the roof.

When to replace a felt flat roof

Flat roofs were, until the 1990s, usually constructed from roofing felt - either torch on roofing felt, or pour and roll roofing felt (usually nailed down onto the roof).

The lifespan of roof felt varies widely depending on the grade and quality of flat roof felt used, and can be anything between 2 years and 20 years.

Often, felt flat roofs are laid with the emphasis on keeping costs down, so the most economical grades of felt are used which, as you would expect, have the shortest lifespan.

The premium grades of roofing felt, are supplied by specialist roofing materials suppliers such as About Roofing Supplies, and are usually laid by professional contractors. 

Roofs constructed using the premium, professional grades of roofing felt will be built up using multiple layers and types of felt. These will typically be guaranteed by the manufacturer to be durable for 10 years to 20 years, with an expected lifespan of another 5 years to 10 years. Find out more about these products here.

The areas most prone to leaking on felt flat roofs are the joints, known as 'laps'. Water gets in through the joints over time - particularly if rain pools into puddles on the roof and does not drain away, Once water has penetrated onto the boards below, these expand, trapping the moisture and as they do so the roofing felt pulls away from the roof boards which only makes water ingress more likely, eventually leading to failure.

Ideally a flat felt roof should be regularly inspected for leaks (at least annually) and these should be repaired as soon as they are identified.

Over time the roofing felt will deteriorate and will become more brittle and prone to cracking and leaks, due to the action of the sun, UV exposure and weather, and replacement of the felt, and the boarding underneath, will be unavoidable.

Typically, when felt flat roofs start leaking, this is an indication that they are reaching the end of their lives and replacement should start to be considered, as repairs should be viewed as a short term solution.

When to replace a GRP flat roof

GRP flat roofs - often known as fibreglass flat roofs - have enjoyed enormous popularity over the last 10 years to 15 years.

GRP roofs typically have a manufacturers guarantee of 20 years, and an expected lifespan of at least another 10 years.

Assuming that these roofs were laid correctly in the first place they are very resistant to leaks, however the initial laying of a GRP flat roof is more challenging than many installers anticipate and leaks are usually due to installation errors rather than the GRP roof reaching the end of its useful lifespan.

Assessing the cause of a leaking GRP flat roof can be quite challenging due to the seamless construction of a GRP roof, however where the leak has been identified, repair can be relatively straightforward. Find out more about these products here.

If repairs to small areas of a GRP roof do not resolve the leak, then consideration should be given to replacement of the entire roof, as it is likely that the root cause of the issue is installation error (use of boards that were not completely dry during installation for example), and the only solution will be replacement of the entire GRP roof.

Temporary repairs to flat roofs

We supply a range of products which can be painted onto flat roofs to extend their lifespan.

Products, such as Cromapol, are waterproof paints that are liberally painted onto areas where leaks are known or suspected, or the deterioration of the roof is visible, and are short terms solutions used to address leakage temporarily (for a few years only).

These products do not have a guarantee because they are dependant upon the condition of the existing roof, however typically they will extend the lifespan of a flat roof by up to 5 years. Find out more about these products here.

When to replace a pitched roof

Pitched roofs can be constructed from a wide variety of materials such as clay roof tiles, concrete roof tiles or roofing slates.

A leaking pitched roof can be caused by failure of the tiles or slates due to ageing, leaks from flashings, or water ingress through the verges.

When to replace a clay tile roof

Modern clay roof tiles are typically supplied with a 30 year manufacturers guarantee, however in many instances clay roof tiles are in usable condition after 100 years, and we have seen examples of clay roof tiles that are in excess of 200 years old and still have many years life left in them!

Older (pre 1980s) clay tiles can be susceptible to frost damage, which leads to the tile cracking and leaking. This is because older roof tiles were rarely manufactured to the high standards that modern roof tiles are subject to. The rigorous UK and EU standards that we rely on in the 21st century are in place to ensure that modern roofing materials provide a log service life.

If your clay roof tiles are breaking up, this is a sure sign that the roof needs replacing, and often once a few tiles start cracking, examination of the rest of the roof reveals that many of the other tiles are cracking and need replacing promptly.

When to replace a concrete tile roof

Concrete roof tiles are cheaper than clay roof tiles, and were the primary roof tile of choice for rebuilding the roofs of Britain after the Second World War, right up until the 21st Century, when the benefits, and narrowing of the cost differential, lead to clay roof tiles becoming as popular as concrete tiles.

The cost saving made on concrete tiles is reflected by their much shorter service life than clay roof tiles. Whilst still being in good condition after 50 years is not uncommon, concrete roof tiles in serviceable condition after 60 years to 70 years are a rarity.

Concrete tiles are vulnerable to frost in the same way as clay roof tiles, but are also far more susceptible to erosion due to wind and rain which leads to thinning and cracking of the roof tile.

Concrete roof tiles are inherently brittle when new and become increasingly fragile with age, meaning that contractors fitting satellite dishes, solar panels or repairing chimneys often break them inadvertently, leading to leaks.

Usually the first indication that concrete roof tiles will need replacing soon is when they look very pale. This is because the surface coating has worn away leading to gradual delamination, usually due to the effects of the wind and weather.

When to replace a slate roof

Roofing slates, like clay roof tiles, have very long lives with many roof slates from leading manufacturers such as SSQ, currently being offered with guarantees between 75 years and 100 years.

Older slates - particuarly Welsh slates can often last in excess of 200 years, and are relatively unaffected by the weather - after all they have survived millions of years underground before being quarrieed and shaped into roofing slates!

However, when roof slates start to delaminate or crack - often as a result of frost damage - this should be seen as a clear sign to replace them.

Usually just replacing the cracked slates is just a temporary solution, as usually they all fail at a similar time, so cracking and delaminating should be seen as an indicator that the roof will need to be replaced. 

Further details of our slate range can be found here.

When to replace a leaking roof

Roofs often leak for reasons other than the clay roof tiles, concrete roof tiles, roofing slate or flat roof felt failing.

A common cause of leaks is from lead flashing around windows, bay windows and chimney pots, where it is chased into the brickwork and the chase is then filled with mortar.

Over a relatively short period of time, the thermal expansion of the lead leads to the mortar cracking and water gets into the joints. This is easily repaired using Flashpoint Lead Sealant - further details of which can be found here.

The brickwork that chimneys are constructed from is vulnerable to both damp and to leaks from the soakers and flashing around the edges. This is often treated with a masonry sealant to waterproof the brickwork - details of which can be found here.

A common cause of leaks on tiled and slate roof is from the verges: Until recently the verges on tile and slate roofs were filled with mortar which cracked over time leading to leaks - indeed this used to be the leading source of warranty claims on new properties submitted to the NHBC.

The Building Regulations were amended in 2018 with the addition of BS 8612: Dry Fixed Ridge, Hip And Verge Systems to require all new properties, and re-roofing and repairs of existing properties, to be constructed with plastic dry verges, which are mechanically fixed to the roof and will stay waterproof for the life of the roof. Further information on these products can be found here.

Where can I buy roof tiles near me?

Is your roof in need of replacing? About Roofing Supplies stock a large range of roofing materials including concrete and clay roof tiles. Our roof tiles are not only hard wearing and versatile but are offered at affordable prices.

Why not visit one of local branches below, or we also offer a nationwide delivery service:

How To Fit A Chimney Pot

How to fit a chimney pot

Chimney pots are made from clay, and are then fired in a kiln to make them resistant to the heat from the smoke and fumes that will travel through them when in use.

Replacing a chimney pot requires a tall ladder, and a head for heights - if you are in any doubt at all, the you would be wise to pay a roofing contractor to carry out the work for you.

Selecting the correct chimney pot

If there is an existing chimney pot you will need to measure the external dimensions at the top and the bottom of the chimney (as many styles of chimney pots taper inwards from the bottom up), and the height of the chimney pot, so that you can purchase a direct replacement, which will not only look right but will also be easier to fit as you will be replacing like-for-like.

If you are fitting a new chimney pot you need to take into account the ratio of the opening at the top of the fireplace to that of the top opening of the chimney pot, which needs to have a ratio in the range of 1:8 to 1:10 (the top of the chimney pot needs to be smaller than the opening at the top of the fireplace).

Also, you need to ensure that the internal dimensions of the base of the chimney pot that you are looking to purchase should always be equal to or greater than the external dimensions of the flue.

Replacing a broken chimney pot

If you are replacing an existing, damaged or broken chimney pot you will need to completely remove what is left of the existing pot, and any mortar holding it in place.

You will need to be very careful, as chimney pots can be surprisingly heavy - many older pots were manufactured from very substantial clay and subsequently can be disarmingly heavy.

It will be a tricky job to remove the chimnney and the mortar holding it in place (assuming that it is still fixed in position) and you will then need to carefully and safely get the broken pieces down to ground level.

Fitting a new chimney pot

Firstly, carefully lift the chimney pot up to the roof - the safest way to achieve this is by using a length of rope to haul it up.

Attempting to carry the chimney pot up the ladder is unwise and should not be attempted.

Once the new chimney pot is up on the roof it should be placed over the flue opening in the chimney stack, which will allow you to judge if the base will correctly fit.

If the base of the pot does not match the size of the opening, pieces of slate can be used to narrow the opening, which will provide a secure base for the chimney pot.

Using a 3 inch (75mm) layer of mortar (made from four - rather than three - parts of soft sand to one part of cement to reduce the risk of mortar failure) around the flue opening, bind the base of the chimney pot into the mortar, pressing firmly into place once you are happy with the position of the pot.

Dampening the area around the base of the pot, any slate used over the flue opening, and the stack stops the mortar from drying out too quickly and gives you longer to make adjustment to the positioning of the chimney pot.

Once the chimney pot has been correctly positioned you need to taper the mortar away from the base of the pot using a trowel, at an angle of approximately 45 degrees, to allow rain to run off - this is known as 'flaunching' the base.

You should then leave the pot, and not use the fire, for 24 hours to allow the mortar to set, and then it should be inspected to confirm that there are no cracks in the mortar or fissures that could allow water or bird ingress.

Maintenance of chimney pots

Chimney pots require very little maintenance other than an inspection every 5 years or so to check it for cracks and to ensure that the mortar is also in good condition and that the chimney is still held securely in place.

Where can I purchase chimney supply near me?

About Roofing Supplies stock a wide range of clay & metal chimney pots, cowls, chimney caps & chimney flues to prevent drafts and encourage airflow. For a chimney supply solution that is reliable and affordable, look no further.

All of our local stores are listed below but we do also deliver nationwide:

How long does it take Cromar Cromapol roof coating to dry?

How long does it take Cromar Cromapol roof coating to dry?

Cromar Cromapol Acrylic Waterproof Roof Coating is a fibre reinforced liquid acrylic resin dispersed in solvent, and is designed to prevent the ingress of water.

Cromapol is suitable for general waterproofing and sealing of roofs, pitched surfaces & for sealing flashings, will waterproof instantly even in damp or wet conditions, and will not wash off while curing.

Following surface preparation, one coat only is required.

Cromapol should be applied in temperatures between 5 degrees c and 25 degrees c.

Drying time can be up to 1 week depending on the ambient temparature, and the thickness of the coating as applied.

It is worth noting that Cromapol may remain soft for a further period, but this is not detrimental to its waterproofing abilities.

Further details on Cromar Cromapol can be found here.

How can I stop birds from nesting in my roof?

How can I stop birds from nesting in my roof?

As the countryside has been built on, and our national (and indeed global) landscape has become increasingly unrbanised, many species of wildlife have been displaced.

The most numerous of these are birds, and being amongst the most adaptable and intelligent of creatures they have found places to live and nest in the built enviroment - often in the stucture of houses, and usually in the roof area.

Some view the colonisation of their properties by birds as a positive thing, others see it as a nuisance and seek to prevent the birds living and / or nesting in the roofspace.

Broadly, birds enter the roof in one of two areas: the chimney or underneath the roof tiles in the eaves: There are easily installed, economical solutions to both situations!


Birdguards are supplied with a bracket that easily clips around the chimney pot, allowing the chimney to continue to be used, but preventing the entry of birds. These are available in either Terracotta or Buff finishes over a durable metal body and are weather resistant as well as bird resistant and will have no effect on the performance of the chimney - if it is in use.

Birdguards also act as chimney caps limiting the effects of wind and weather down the chimney. Easy to fit and inexpensive, these are an extremely popular solution to birds nesting in the chimney or entering properties down the chimney. For further details please click here. 

Chimney Caps

If the chimney is not in use, a discreet and popular alternative to Birdguards are Chimney Caps.

These allow the chimney to 'breathe' (preventing the build up of damp, whilst keeping rain, drafts and birds out.

These are the most cost effective solution, and either clip inside the chimney pot, using the integral four flexible wire legs pre-fitted to the cap, or clip around the chimney pot using the supplied bracket.

Chimney caps are so quick to fit that roofers often joke - quite correctly! - that it takes longer to pitch the ladder and climb it, than it does to fit the actual Chimney Cap! For further details please click here.

Comb Filler

Small birds in particular, such as House Sparrows and Starlings, often enter the roofspace through gaps between the roof tiles and the bargeboard or fascia.

Double Roman and similar profiled 'wavy' tiles are particuarly prone to this. The solution is to fit Comb Filler which is easily fitted by removing the eaves course of the roof tiles and then nailing the comb filler along the top of the bargeboard, before re-laying the tiles. Easily fitted, these 1 metre strips are simply nailed into place. Further details can be viewed here.

What are the most common causes of a leaking roof?


Leaks in roof are usually caused by one of three reasons:


Roof tiles / slates are often cracked by contractors when work is carried out on the roof such as the installation of solar panels or cleaning windows.

Roof tiles / slates should not be walked on, and rarely survive this happening - if left, even a hairline crack will permit the ingress of water.


Many roofs have cement verges. These will eventually crack allowing water into the property.

All new build properties, and many refurbishment projects, use plastic verges which are a 'fit and forget' product that seals verges permanently against the effects on water ingress.


Lead flashings, particularly on older properties, are chased into the wall, with the gap, or 'chase', then filled with mortar. The expansion and contraction of the lead as it warms up in the sun and then cools at night, leads to mortar failure which in turn leads to water entering the property.

The use of silicone sealants is little better than cement, as these products will rarely last for more than a year under these conditions.

The solution is the use of a proper Lead Sealant which is specifically designed for this purpose and will provide many years of leak free service!


Do you have a roof that’s leaking? About Roofing supplies roof repair materials in each of our branches listed below:

Can’t make it to one of our branches? Don’t worry, we offer a nationwide next day delivery service delivering roofing materials & supplies to West Sussex, Mid Sussex, Surrey & South London, as well as parts of Kent & East Sussex using our own fleet of vehicles. If you’re not based in these areas, we also use parcel and pallet carriers.

Which roof tiles are suitable for a low pitch roof?


Low pitch roofs are generally considered to be those below 22.5 degrees, and above 10 degrees.

There are a number of roof tiles available that are suitable for installation on low pitch roofs.

Concrete interlocking roof tiles such as Sandtoft Double Romans and Sandtoft Calderdales are the most popular concrete options, with the Imerys HP10Imerys HP20 and Sandtoft 20/20s being the most popular clay options.

Alternatively, another solution to the challenge of which roof tiles to use at low pitches is to use Klober Permo Extreme breathable membrane instead of standard breathable membrane.

Klober Permo Extreme breathable membrane enables the use of roof tiles down to pitches as low as 12.5 degrees (depending on the roof tiles being laid). This is a very popular option, indeed the only viable solution, where an exact match to the existing roof tiles on the main roof is essential, such as clay handmade tiles where the minimum roof pitch that the tiles can be installed at, being 35 degrees typically, precludes their use normally at such low pitches.

It is worth noting that the rafter length of a low pitch roof can have a bearing on whether particular tiles, even if they are suitable for that particular pitch, can be used.


You can find roof tiles suitable for a low pitch roof in any of our branches listed below or we deliver nationwide to you:

Which roof shingles are the best?


Our own brand felt shingles are manufactured in Russia, and we also supply the Dakota Felt Shingle range which is manufactured in Canada. Many people consider these two ranges of felt shingles as the best available in the UK - which is why we supply them!

These felt roofing shingles are more than capable of withstanding anything that the British weather can throw at them, and have long service lives.

We strongly advise our customers to beware of cheap felt shingles, usually manufactured in China, Italy or Spain, which have a reputation of being made with poor quality bitumen and rarely last more than a handful of years.

What are some roofing shingle suppliers near me?

Here at About Roofing, we stock and supply heavy duty Canadian & Russian Felt Shingles, as well as Eastern White Cedar roofing shingles imported from Canada. Available to purchase online or from one of branches listed below:

Sourcing roofing materials locally and online

Sourcing roofing materials locally and online

Ordering roofing materials online

Most of us research products and shop online these days. When ordering Christmas presents, clothes, and even our weekly food shopping, the process is straightforward and the order will be delivered in a small box, or a few bags, a day or two after the order is placed online.

But what if you need 10,000 roof tiles for your extension roof, five bags of gravel for the drive or a number of large tins of waterproofing paint for your flat roof? These products will be delivered on big lorries with cranes, or by pallet couriers - surely it's not straightforward?

Actually, ordering roofing materials online is very simple - you add your goods to the basket on the website, and they are then delivered shortly after in much the same way as your delivery from other online sellers - it's that easy!

Often our customers are unsure of the types and quantities of the materials that they need, or they have architects drawings which require specialist quantification - in these scenarios the order cannot easily be placed online as it is not readily apparent which materials are required, or they may even be items that need to be specially ordered and supplied directly from the manufacturer: so what happens in these instances? Here at About Roofing Supplies we deal with these kinds of situations on a daily basis - all we ask our customers to do is to forward us their plans or drawings by email or in the post, we quantify the materials required, and then send the customer a pro forma invoice setting out which materials are required, the cost of delivery etc and payment details.

Unlike our competitors, here at About Roofing Supplies we have experienced staff who are available in person, via email or by phone, to ensure that your order is dealt with by a member of staff that you can actually speak to regarding your order, and who will know who you are and will know all about your order - no call centres here at About Roofing we promise!

Ordering roofing materials locally

There are pros and cons to ordering your roofing materials locally.

On the positive side, you can deal with your supplier face to face, see samples of the actual tiles that you are buying, and the delivery costs are sometimes lower than ordering online, however there are drawbacks too: Are you sure that you are getting the best price? Online suppliers are often cheaper than your local supplier, however ordering online from a website, rather than a human being, is not the way that everyone likes to purchase goods - especially expensive, bulky and often complex building materials, such as roof tiles.

Also your local supplier, particuarly if they are a builder's merchant, may not have the experience to process your order and to supply the right products for your project - unlike a specialist roofing supplier, such as About Roofing Supplies. They might be local, but you will get none of the advantages of dealing with a local specialist.

Where can I buy roofing materials near me?

Using a specialist roofing supplier such as About Roofing Supplies gives you the best of both worlds: Friendly experienced staff in real branches with actual stock to see and purchase, at online prices - the best of both worlds, both online and local!

Our local branches are listed below but we do also deliver nationwide:

Which roof tiles last the longest?


In practical terms, clay roof tiles and natural slates last the longest, with usable examples over 100+ years being relatively common - on occasion customers bring in clay roof tiles or slates to be matched that are much older.

We have seen clay roof tiles that are estimated to be at least 250 years old that still had plenty of life left in them.

Concrete tiles degrade over time in both appearance and integrity, and they will certainly be approaching their 'twilight years' after 60 years - having said that we are regularly asked to match concrete roof tiles laid just after the end of WW2 - over 70 years ago - that are still in fair condition.

Environmental factors such as pollution or severe weather (such as in coastal locations) can have a marked effect on roof tiles: when we see old roof tiles from within the M25 boundary surrounding London, it is readily apparent how much worse their condition is than those that we see of a similar age from the Home Counties.

Roof tiles and slates are not designed to be walked on - doing so, when installing solar panels for example, leads to many breakages and leaks.

Pressure washing of roof tiles and slates is arguably the worst thing that can be done to a roof, and it is strongly advised against. If moss is a problem or unsightly then we recommend the application of a proper Moss & Mould Remover (such as the Cromar Moss & Mould Remover that we supply), and that the instructions are diligently followed. 


You can find long lasting clay roof tiles and natural slates in any of our branches listed below or we deliver nationwide to you:

Five key factors to consider before bulk buying roofing materials

Five key factors to consider before bulk buying roofing materials

There are five main points that should be considered before bulk buying roofing materials:

Will they suit my property?

Not all roofing materials suit every property - a factor that is sometimes overlooked by buyers seeking to purchase roof tiles or slates for their property.

Older properties - pre 1940s for example - are often best suited to handcrafted or hand made clay plain tiles, whilst concrete plain roof tiles, for example, just would not look right!

On modern properties, a contemporary roof tile such as a clay machine made roof tile, or large format concrete interlocking tile are the most suitable option, whereas a handmade clay roof tile would simply look out of place.

Here at About Roofing Supplies we are experts in roofing materials and are available to help you to make the best decision for your project.

Do I like the look of them?

This is a simple point, but a very important point! The roof tiles and slates that you choose are not easily changed in the same way that a pair of shoes that you regret buying can be returned or easily replaced.

Time spent looking at samples, weighing up the features and benefits of the different roof tile types is essential, and we strongly encourage our customers to talk to us before purchasing roofing materials so that we help them to come to the right decision.

Do I have planning permission for them?

Local Authority Planning Departments should always be consulted before purchasing roof tiles - they are there to make sure that properties are in keeping with the local area, and carry out a very important job protecting both your, and your neighbours' interests, and the look of the area.

Are they from a reputable manufacturer?

Not every manufacturer who's products are sold online or through roofing materials suppliers, subject their roofing slates and tiles to the full range of UK and EU testing and certification processes.

Rigorous testing of building and roofing materials is essential to ensure a long service life, satisfactory performance and safety.

Sadly, we are aware of products that are available on the UK market that have not been tested properly, do not meet standards or have warranties that are frankly worthless.

At About Roofing Supplies, we only sell products from manufacturers in whom we have complete confidence that not only do their products meet and / or exceed every relavent standard, but are backed up by a manufacturer who will deal with any issues.

You can rest assured that we would not sell any products that we would not fit onto our own homes!

Am I ordering them from a trustworthy supplier?

Not all supplier of roofing materials are the same!

Many so-called 'suppliers' such as Builders Merchants simply order the roof tiles and slates through merchants like us, rather than stocking them, adding yet another layer of cost, and leaving the buyer exposed to supply errors.

Some roofing materials suppliers - particuarly online suppliers - do not actually stock any of the products that they sell, and rely on ordering the products directly from the manufacturer leaving the buyer effectively relying on the actual manufacturer to have the products that they require in stock.

Few roofing materials suppliers offer a Click & Collect facility and even fewer operate lorries with cranes on them to make unloading easier.

At About Roofing Supplies we have four branches that you can collect from, one of the largest delivery fleets in the industry - and large stocks! Check out our Facebook & Twitter feeds to see our staff and branches!

What are the most cost effective roofing materials?

What Are The Most Cost Effective Roofing Materials?

This is not a straightforward question as the answer depends on your definition of what you view as 'cost effective'. 

This question should perhaps be asked as below:

What Roofing Materials Are The Cheapest To Buy And Lay?

Concrete interlocking roof tiles are the cheapest way to cover your roof assuming that you are looking at the purchase cost of the tiles per square metre, not forgetting the 'hidden costs' of the roofing batten and the nails.

In terms of square-metres-covered-per-pound, then either the 15 x 9 concrete interlocking roof tiles (such as the Redland 49, Sandtoft Standard Pattern and Marley Ludlow Plus) or the large format interlocking roof tiles (such as the Redland Double Roman, Sandtoft Double Roman, Sandtoft Double Pantile amongst others) are always going to the cheapest option.

What Roofing Materials Are The Most Cost Effective Overall?

From this perspective - where we now include the useful lifespan of the roof tiles in our thinking - clay machine made plain tiles are the most cost effective roof covering.

Although slightly more expensive per square metre to initially purchase (including the 'hidden costs' of batten and fixings), clay roof tiles will last at least double, if not three or four times as long over time as concrete roof tiles, so if looked at from the perspective of cost-per-square-metre-per-year, then clay machine made plain roof tiles win hands down.

Clay roof tiles also have an aesthetic advantage over concrete roof tiles, and are looked at as a postive feature that adds value to a property by many people so they should, perhaps, be viewed as not only a more economical long term option, but also one that may well yield a return on the original investment in terms of a higher selling price achieved for the property when it is sold.

How to remove moss from a roof


We stock & supply Cromar Moss & Mould Remover which kills lichen, moss and similar vegetation resulting in growth free roof tiles and slates.

Products such as this can also be used to remove growth on roofs, walls and other external surfaces prior to treatment with surface finishes.

Application is easy: Simply apply by brush or low pressure spray at a rate of 4 - 6m2 per litre per coat, and leave for approximately one hour.

The surface is then cleaned using a stiff bristled brush to remove any loose debris and a second coat can be applied if any growth remains.

The cleaned surfaces should then be left for at least 24 hours to cure, before cleaning again and washing down again, taking care to remove any white deposits which may have formed.

The use of a high pressure jet wash at any stage in this process is strongly discouraged as this has a very high liklihood of permanent damage and degradation of the roof tiles or slates.

It is strongly recommended that a trial area should be coated initially to assess the correct dosage, and that products such as these should not be applied in wet weather to prevent run off and local contamination.

How many squares of felt roof shingles do I need to cover my roof?


Calculating the quantities of felt shingles required is relatively simple:

Each pack of felt shingles covers 3 square metres.

So,the first step is to calculate the area that you need to cover: Lets assume that you have a conventional shed with a duo pitched roof (an inverted 'v' shape) that measures 2.42m x 1.21m on each of the two sides.

2.42m x 1.21m = 2.93m2 x 2 = 5.86m2 total roof area.

5.86m2 / 3m2 packs of felt shingles = 1.95 packs of shingles required.

Always round up your requirements to allow for cuts and wastage, so we will say that you need at least 2 packs.

You also need to allow for the ridge: We know that the ridge is 2.42m long.

To cover the ridges you cut the shingle strips into the individual tile pieces, giving a coverage of 2.4 strips required per linear metre of ridge.

Therefore 2.42 l/m of ridge x 2.4 strips/lm = 5.8 strips needed = 6 strips required. There are 21 strips to a pack of shingles, so you will need to buy a pack to cover the ridge leaving 15 strips spare.

You may, in fact end up using most if not all of the spare shingles when laying the two sides of the roof as there was very little allowance for cuts and wastage (for which 5% is usually allowed).

Roof Shingles vs Roof Tiles: Which is better?


Roof shingles or roof tiles: which is the best roof covering for your property?

The answer to this varies according to where you live: In the Unites States Of America, over 70% of domestic dwellings have felt roof shingles as their primary roof covering, yet we have not heard of a single instance in the UK!

To comply with UK Building Regulations, you could, in theory, use felt shingles, however it is unlikely that a Local Planning Officer would accept these as being 'in keeping' with the local area.

Traditionally in the UK we have used clay or concrete roof tiles, as well as natural or man made slates to cover our houses. To preserve the perceived value of your house in the eyes of potential buyers it would be unwise to use anything else - not to mention the implications for obtaining insurance cover and a mortgage.

How long will roof tiles last?


This is in fact two questions: Firstly, 'How long are roof tiles & slates guaranteed for?', and secondly, 'What is the life expectancy of roof tiles & slates'?

Clay roof tiles are, for example, manufactured to BRE standards with a minimum life expectancy of 60 years in normal conditions.

It should be noted however that 'life expectancy' should not be taken as a guarantee or warranty.

Broadly, roof tiles and slates will remain serviceable for many decades - we can supply natural slates with a manufacturer's guarantee of 100 years.

There are a number of factors that affect the length of each manufacturer's guarantee for each roof and the tiles or slates installed: To obtain a full manufacturer's warranty - which varies by manufacturer and product used - the roof will need to be designed by the manufacturer, installed to all the current standards using a complete suite of products and fixings from the manufacturer's own range.

In practical terms, the life expectancy of clay roof tiles will be 60+ years - on occasion customers bring in clay roof tiles or slates to be matched that are much older. We have seen clay roof tiles that are estimated to be at least 250 years old that still had plenty of life left in them.

Concrete tiles degrade over time in both appearance and integrity, and they will certainly be approaching their 'twilight years' after 60 years - having said that we are regularly asked to match concrete roof tiles laid just after the end of WW2 - over 70 years ago - that are still in fair condition.

The life expectancy of natural slates varies according to the type of slate used and the quality, which will as you would expect be reflected in the price, with life expectancies between 30 and 100 years, whilst man made slates have a life expectancy of up to 60 years.

Enviromental factors such as pollution or severe weather (such as in coastal locations) can have a marked effect on roof tiles: when we see old roof tiles from within the M25 boundary surrounding London, it is readily apparent how much worse their condition is than those that we see of a similar age from the Home Counties.

Roof tiles and slates are not designed to be walked on - doing so, when installing solar panels for example, leads to many breakages and leaks.

Pressure washing of roof tiles and slates is arguably the worst thing that can be done to a roof, and it is strongly advised against. If moss is a problem or unsightly, then we recommend the application of a proper Moss & Mould Remover (such as the Cromar Moss & Mould Remover that we supply), and that the instructions are dilligently followed.

Are roof tiles porous?


Yes roof tiles are porous - they absorb small amounts of water, which then evaporates harmlessly.

Does that mean that roof tiles leak? No. As long as they are not broken and are laid correctly, at the correct roof pitch, they will not leak.

Are roof tiles waterproof?


Yes roof tiles are waterproof.

Being porous they absorb small quantities of water, however the actual tiles will not let water through, and if laid correctly and not broken, no water will get past them into the property below.

The breathable or non breathable membrane laid underneath the tiles also acts as a secondary barrier, albeit only a temporary one.

Can you paint roof tiles?

Can you paint roof tiles?

Need to know more about painting roof tiles? We offer you the best advice on whether you can paint your roof tiles and the do's and don'ts of roof tile painting.

Read more

What causes felt shingles to curl on a roof?


Felt shingles can curl on a roof when the trailing, or bottom edge, has not been fixed.

The effects of the sun can cause the bottom edge of felt shingles to lift if they are not secured, and once they start to lift the wind can often make the issue worse - in extreme conditions the shingles can be damaged or even ripped off the roof.

Premium quality felt shingles, such as our own brand shingles and the Dakota brand shingles that we also supply, have an adhesive bituminous strip on each shingle, that adheres the bottom edge of each course of shingles to the course below, thus preventing wind uplift.

What goes under roof shingles?


In the UK felt shingles are normally used on shed and garden buildings, so for these applications a 3B bituminous felt is used as an underlay as the buildings below, not being subject to habitation, do not require the installation of a breathable membrane under the shingles.

In the United States, as felt shingles are the most popular roof covering on houses, a breathable membrane is used under the shingles.

What is the lifetime of felt roof shingles?


Both our own brand range of felt roof shingles, and the Dakota range that we also stock and supply, have a 15 year manufacturer's warranty, with an anticipated lifespan of 35+ years.

How to install roof shingles


Our felt and cedar shingles are quick and easy to install, and both require a minimum of skill and effort.

Installation details for felt shingles can be found here.

Installation details for cedar shingles can be found here.