Frequently Asked Questions

What are Stone Slate Roofs

Stone Slate Roofs are a popular feature of houses in the pennies giving a distinctive skyline. Originally stone slate was the only alternative roofing material to using the more traditional thatch type of roof. Stone slate roofs are distinctive and cannot be replicated easily with modern materials meaning they are pretty much here to stay. However in some cases modern materials have been used.

Stone slate roofs are particularly hard wearing and with regular maintenance should last well over 100 years. A full re-roof is rarely required and often you can reuse much of the original material. However this obviously varies from roof to roof top.

Local sandstone and slate as well as slate from further afield such as Wales and West Moorland have been traditionally used.

You should use a professional roofer such as Assured Roofing who will know how to seal slate roof to stone in the correct manner so it lasts.


Ensure you check your roof at least once a year for minor problems such as loose slates, loose ridges on the outside and look for damp patches especially on roof timbers internally. If in any doubt get a specialist slate roof repairer in to check, not all cracks, flaking or changes in colour necessarily mean the roof requires repair.

Keep on top of any vegetation that starts to grow in the roof or gutters and remove moss debris and anything that may hold water or prevent it from flowing off the roof. Watch out for ivy as this can dislodge slates the higher it grows.

Hiring a roofing contractor with specialist and proven experience in working with stone slate roofs is advisable. It is common sense to check that they can show you local examples of the quality of their work.

If you are in doubt a structural engineer can give a professional opinion and possibly recommend a specialist slate roofer. Only a prolonged period with a lack of care can cause such problems to develop.

Try to find replacement stone slates locally as should have the same proportions as the existing slates, your local specialist roofer should be able to help. Agree with your contractor and ensure that this agreement is observed.

Reclaimed stone slates can be a suitable alternative but only if you can be sure that they are from a genuine source, such as a demolished building all to often such stone for roofs has not been legally obtained.

Traditionally stone slates are fixed using oak, treated softwood, or copper pegs, or copper nails. Stainless steel nails or galvanized nails should be used in the main roof structure.

Before any work starts photograph the roof this is then a record of the original detail which can be used for comparison and as a guide to ensure the work is going according to plan.

Do not leave minor problems, as they will invariably lead to larger and more costly problems over time.

Whilst you can turn over stone slates this is not always advisable. The topside of a slate may have been treated or be naturally more weather resistant than the underside and if turned over the underside can rapidly deteriorate when exposed to the elements.

An irregular shaped stone slate roofs maybe more water tight as it has settled during its first few years, the uneven shape of the ridge is a common feature. Trying to make the roof more regular may be costly to achieve effectively.

Do not bed stone slates in mortar. The mortar can draw moisture between the stones and into the roof, and also damages the stone.

Do not seal the stone slate roof with any coating including tar. This can seal in moisture and cause fungal attacks and many other undesirable affects on the slate and roofing timbres.

Back to top

What are Roof Trusses?

Roof Trusses are the timbre frames that roofs sit on. There are a wide variety of systems and configurations on the market and a more detailed description of Timbre Roof Trusses can be found here

Back to top

Why convert from a flat to a pitched roof?

There are a number of reasons why you would want to do this from the aesthetic to the practical. The work involved in changing a flat roof into a pitched roof is a simple and will no doubt alter the look of your home for the better.

Once the pitched roof timber work is complete the pitched roof can be slated or tiled in the same style as the rest of the building to ensure it looks consistent and blends in well with your property and your neighbours.

Assured Roofing have been altering flat roofs to pitched roofs providing a professional high quality service from start to finish.

The benefits to you of converting are as follows:-

  • Lower maintenance and naturally rain run off
  • Appearance blends in with the rest of your property
  • It is a permanent repair that lasts
  • In some cases it can Increase the value of your property

Back to top

What are soffits and fascias?

Soffits are underside of an architectural structure such as an arch or overhanging eaves. A fascia is usually a wooden board or other flat piece of material covering the ends of rafters or other fittings on the roof of a property.

Back to top

Gutter Maintenance

Defective gutters can be the source of many sorts of damp problems in a building, therefore maintaining your gutters is an important aspect of maintaining your home.

The guttering and associated pipe work are there to carry rainwater away from a building, if they are blocked or broken, water can run down the outside wall or (other areas), which as well as looking unsightly will eventually damage the area that is getting wet. Parts of your property can get damp, have mould and rot. Problems are only really noticeable when it rains, so you should always notice anything odd and take action before problems set in.

Autumn is the best time of year to maintain your gutters as all the leaves have fallen and the weather is still mild enough before the winter sets in to resolve any issues that have arisen.

Typical maintenance tasks include:-

  • Removal of Gutter blockages
  • Clearing downpipes
  • Correcting sagging guttering
  • Repairing or replacing Corrosion and cracks on metal guttering
  • Cracks in plastic and cement guttering
  • Repairing Leaking joints
  • Replacing sections
  • Painting guttering (not suitable for all guttering)

Back to top

What is roofing slate?

Roofing Slate (also called roofing shingles), can be installed by a slater or experienced and qualified roofer. Roof Slate has two lines of breakability known as the cleavage and grain. These make is possible to split the stone into thin sheets ideal for slating roofs. Slate retains a natural appearance while at the same time remaining relatively flat and easily stackable and therefore ideal for roofs.

Slate is particularly suitable as a roofing material as it has an extremely low level of water absorption which also makes it extremely resistant to frost damage

Back to top

What are plastic verges?

Plastic verges provide a cheap alternative to the more traditional mortar verges, in some cases they look better but it really depends on circumstances. Assured Roofing can advise the most suitable type of plastic verges for roofs to fit to your property and at highly competitive rates.

Back to top

Re-Roofing or Re-slating a roof

The process of re-slating a roof is as follows:-

  • Firstly the existing slates need to be stripped off and stored it makes sense to store them sorted by length, size and thickness thought this is not necessary.
  • Next you will need to re-felt the roof - felt is a breathable membranes and is essential to allow water vapour to dissipate due to natural air movement to move through which also reduces wind pressure on the underside of the slates.
  • The roof may need re- battening by using softwood attached to the roof rafters
  • Re-slate the roof
  • Re-fix lead flashings and any chimney aprons
  • The last two stages are the "Dry fix" (replace any dry verges, hips and ridges) and the "Wet fix" (verge pointing, verge fair ends, bedding and pointing of slate at the gable ends and the ridges with mortar)

Back to top

How long will felt roofing last?

A felt roof can last for around 10-15 years if laid correctly by a professional and experienced roofer. As such felt roofing is often the most cost effective way of waterproofing a flat roof. If the roof is properly maintained every few years the roof will last longer than if it is not maintained properly.

Back to top

Can you maintain or fix a problem with the lead work on my roof?

Lead work is a craft, a skill and a specialist roofing service that Assured Roofing have been fine-tuning for more than 15 years. Mainly used in churches and listed buildings it is also used on chimney stacks and bay roofs. Thinner quality lead work that used to be installed in the past, can slowly wear away causing sudden leaks.

Assured roofing have all the specialist skills and experience to manage and maintain the lead work on your roof this includes:-

  1. Full and Comprehensive Site Survey
  2. Full Preparation works
  3. Installation of lead sheet roofing & lead flashings
  4. Lead Work Repairs and Maintenance
  5. Lead Welding

As part of Assured Roofing's commercial services we will assess such things as:

  • The presence of serious ripples or splits
  • The use of oversized lead roof pieces
  • Poorly located fixings which restrict the normal thermal movement of lead
  • Worn or inappropriate lead roof fixings
  • Lead roof under lays
  • Heating and insulation, which can affect the lead roof decking
  • Corrosion on top or on the underside of the lead

Whether to repair or renew a commercial lead roof can also be influenced by other factors.

Lead Roof Tips

Use plastic or wooden tools to clear snow as this will prevent damage to lead work.

Abutments are the most vulnerable areas of the building fabric and usually occur where one part of the building meets another. Usually lead or zinc flashings are used to protect the joint from the weather. Inspect flashings to check that they are in good condition, without holes or splits.

Back to top

Can Assured Roofing help with Roofing joinery?

Traditionally roofs were constructed on site using sawn timber, with the joints simply nailed together. Modern roofs are frequently erected using prefabricated roof trusses. These are built off-site and delivered ready to be positioned and linked together to form the roof.

With traditional roofs you have a strong roof structure with mostly open loft space with strong floor joist which is suitable for additional storage. You can also build complex roof designs for more unusual buildings. At Assured Roofing we have the skills and experience to maintain and replace traditionally constructed roofs.

Back to top

How can I use the loft space in my modern house?

Prefabricated Roof Trusses are much quicker to install and used on most new builds, the problem with them is that unless a large open space was originally specified (not in most cases) it is difficult to utilize the space for storage or as additional living space. This is because the trusses effectively form a mesh that just gets in the way. Space is a precious commodity in any home and Assured Roofing can convert or replace a prefabricated roof allowing you to utilize the space.

Back to top

What is GRP Fibre Glass Roofing?

GRP Stands for Glass fibre Reinforced Plastics, and is usually referred to as Fibreglass or Composite Plastic. GRP is incredibly versatile, with a vast range of properties. Whilst it is plastic it has few of the disadvantages of conventional thermoplastics in everyday use making it an ideal roofing material.

A properly laid fibreglass roof should last for at least 30 years before it starts to noticeable deteriorate. As a result GRP fibre glass roofs are an ideal solution in many roofing requirements.

It will not melt, but will burn in the same way wood will, but can be easily made fire retardant. It is seven times the stronger than steel, yet very light weight and can absorb a tremendous amount of energy making it a common for racing cars, boats, baths and aeroplanes. Most importantly GRP can be moulded using a former or tool and in its simplest for know as hand-lay.

This flat roofing system is a new generation and the answer to traditional leaking felt roofs. Since it is seamless, it eliminates all the problems and short life span of felt or bitumen materials. GRP fibre glass roofing is attractive, cost effective, durable, long lasting, and maintenance free.

As a result fibre glass roofing offers long term peace of mind and genuine value for money.

Back to top

What are the benefits of Velux windows?

Whether you are considering a loft conversion, extension or a sun room a Velux window can add the all important natural light to make the room spacious light and an enhancement to your home.

Natural light or daylight is important to enhance the quality of our lives and indoor environments. The many shades and variations produced by natural light help turn a house into a real home. Couple that with fresh air, and Velux windows bring quality of life, and help create healthy places to live and work. Velux windows have been available for over 60 years, which means that Velux windows are high in quality and durability.

Velux windows are designed to keep heat loss to a minimum, to maximise warmth from the sun and to let in natural daylight and fresh air. As a result Velux windows can help reduce fuel bills and therefore carbon dioxide emissions.

Back to top

Are your windows cloudy or have mist between the panes?

Over time all windows will deteriorate and maintenance is required to keep them in good condition and make them last longer. If the main glazing unit has deteriorated, it should be replaced. New, low-energy pane have much more insulation and will not only solve this problem but also help with your energy costs.

If your glazing unit has deteriorated there will be increased heat loss through the pane, either due to poorer insulation or in some cases down draughts from the pane.

If the pane seems dim or you can see obvious signs of humidity between the layers of glass the glazing unit might have deteriorated. Turn the sash around to the cleaning position and if water drops run between the layers of the glass then this is a dead give away that humid air has penetrated the space between the panes.

Velux provide a maintenance kit to help service your window so it lasts longer, before more expensive replacements are required.

Back to top

How does condensation form on my Velux Window?

This is a completely natural phenomenon and not a defect in your Velux roof window. It occurs when the humidity in the building is too high relative to the outside. Condensation then forms on relatively cold surfaces, which is usually a window pane. The obvious answer is to ventilate the room by opening the window.

Condensation should not normally form between the panes unless the pane has deteriorated.

Back to top

What causes Velux Window drafts?

This can occur for a variety of reasons, but can be due to Worn out gaskets

The gaskets in a Velux roof window are developed to be air tight, but if your gaskets are around 10 years old or more, they may be be stiff and dry and no longer provide the necessary contact. As a result, cold air can penetrate the gasket cause a draught. Gaskets should be replaced so that the window can close completely between the frame and the sash.

Alternatively the draught could come from around the frame, this may be due to age. Assured Roofing can help advise whether the draught can be sorted out with simple maintenance techniques or whether greater work is required to resolve the problem.

Back to top