A Modified Bitumen is a key element in any built-up roof.
This type of roofing system was developed in Europe during the sixties and later introduced in the U.S. in the early seventies. Modified refers to the addition of plastic or rubber-based polymeric binders to the asphalt or “bitumen” to improve its roofing performance and durability. Modified Bitumen Flat Roofs are usually assembled using one, two or three plies.
The Modified Bitumen Membrane is made up of multiple layers in what is essentially a “factory assembled” built-up roof. During the roofing manufacturing process, several coats or laminations of modified bitumen are reinforced with a woven fiberglass, or polyester fabric reinforcing mat or a combination of both. They are then finished with either a smooth or granular top surface.
The Granular type comes in different colors. The smooth surface type is then coated with either an aluminum or white surfacing on site. The coatings are used to deflect the damage from ultra-violet rays from the sun as well as keeping the roof surface cooler.
Modified Bitumen Roofs exhibit many characteristics of a built-up roof (BUR), yet affords the ease of application on a single-ply roof. This offers various specifications which allow for multiple plies, which provide redundancy and exceptional resistance to heavy traffic, punctures and tears. Modified Bitumen membranes also have low-temperature flexibility and are resistant to membrane fatigue(break down).
There are two types of Modified Bitumen Systems
- APP (Atactic Polypropylene) roofs are applied using a heat-welded method. The top surface comes in either smooth or granular. The consistency and uniformity of the factory produced sheet results in a membrane that has greater stability and flexibility than that of a laminated built-up roof system.
- SBS (Butadiene Styrene) roofs are usually applied using hot asphalt, bonding adhesives, heat welding or heat activated self-adhesives. The top surface is a mineral granular of choice of colors. It has the benefits of a built-up redundant system with the quality of a factory single ply membrane.
flatroofs.ie employ expert technicians and are qualified to install modified bitumen roofing on any commercial and industrial flat roofing system in Ireland.
TPO Flat Roofing
TPO is an excellent roofing system for any climate. TPO, it is said is an advancement and a great improvement to traditional flat roofs that are being explored today. The seams of TPO roofs are welded instead of glued. They are less likely to separate when heated and consistent environmental changes.
The Manufacturer certify the flat roof contractors to install the membrane and in turn honor the warranty. A TPO flat roof material gave a white surface that reflects ultraviolet light and keeps the structure cooler than other options.
Because the system is relatively new, revisions and improvements are happening everyday. This requires flat roof repair contractors addressing shrinkage caused by prolonged exposure to UV rays.
They cause stress on flashing and seams. The warranty on TPO roof systems is 15 to 20 years. The welds of both hand-held and walk-behind welding must be checked. Welding that does not take, must be patched or replaced.
Long and short seams require different welds. A lack of uniformity can cause seams to fail and leaks on the roof. Commercial skylights for flat roofs cannot be welded with walk-behind welders used for long seams.
Short seams are needed for A/C units, drains, vents, and skylights. These areas are welded with a hand-held heat gun. The heat difference between the long and short seams becomes an issue.
Heat-welded seams must be correctly calibrated throughout the day of flat roof installation. The quality of a welded seam is affected by wind, cold, and humid weather conditions. A tool is used to check the seam quality to ensure the welds take.
With many different types of Flat Roof to choose from we have prepared a listed of Pros and Cons of each below
Newer and newer flat roofing materials are appearing yearly. They wear better than older material and made with better technologies than before.
Domestic/Homeowners and Commercial business can choose among four kinds of flat roofs.
All 4 types of flat roofing systems can cost €250 to €350 per/square foot, prices do vary according to region and size of the roof. Flat roofs usually come with a 10 to 25 year warranty but the roofs can last up to 30 years if properly installed and maintained.
Built-Up Roof or Hot Tar flat roofing similar to roads
The traditional hot tar and gravel roof is built from three or more plies of waterproof material alternated with hot tar and ballasted by a layer of smooth river stone. Once made of tar paper, these types of roofs gradually are using more-advanced materials such as fiberglass membranes.
- Pros: Gravel is an excellent fire retardant. Attractive for windows and decks that overlook the roof. It’s the cheapest of the four roof varieties.
- Cons: Very heavy. Joists sometimes have to be strengthened. Smelly and messy to install. Installation’s not recommended for occupied homes. It’s not a DIY installation job, and it is hard to find the source of leaks. The gravel has been known to clog gutters.
Heated Modified Bitumen
A single-ply rolled roof similar to ice-and-water shield, but impregnated with a mineral-based wear surface. Torch-down systems involve heating the adhesive as the material is unrolled. Newer peel-and-stick systems are safer and easier.
- Pros: Peel-and-stick material can be installed easily. Its light-colored mineral surface reflects heat and cuts energy bills. Its price is in the middle of the pack.
- Cons: Torch-down application is a fire hazard, and not recommended for occupied buildings. It has been know to scuff and tear rubber-membrane roofs.
Rubber Membrane Flat Roofing
EPDM (short for ethylene propylene monomer) is a true rubber. The durable material resembles an inner tube, but it’s engineered to resist damage from sunlight. EPDM can be mechanically anchored with fasteners, ballasted with stone, or glued in place.
- Pros: Homeowner-friendly installation. The material’s relatively light yet highly resistant to scuffs and tears. Leaks are easy to patch.
- Cons: The standard black material absorbs heat, and light-colored coatings (recommended in warm climates) add 30% or more to the cost. Even the black version, though, costs more than BUR or modified bitumen. It’s also more vulnerable to punctures than other choices.
Flat Roofing Options & Costs
Flat roofing has come along way in the last then years since the days of them just being a cheap alternative to a pitch roof and nearly always leaking. That has changed now and thanks to the development of better materials.
We live in a climate of consistent damp and wet and all roofing systems need to be able to cope with that certainty not to mention driving winds and unpredictable conditions. Our wind driven rain will test any roofer worth his salt. “Modern materials, design and ventilation have completely changed flat roofing”
Flat roofs which should not not be totally flat as its needs to give a small fall in order to direct water using 1 degree fall to direct water to the gutter. Flat roofs are popular usually on rear or side extensions avoiding the need for an apex or pitch. With some buildings depending on where the windows are giving better views and vista.
Dublin Flat roofing
Our roofing team are highly trained flat roofs in dublin. We know that poor drainage is usually the number one cause of leaks in flat roofs, because the water is more likely to collect on top. Regular monitoring is required for structures with flat roofs to prevent puddles from forming since the weight of the water will eventually lead to structural damage. Bitumen or Asphalt is a common material used on flat roofs and a contractor will need to repair any cracks caused by drainage issues. To seal cracks on a flat roof, the cost can be approximately €500 to €1,200.
Roofing Repair Costs is based on material and location of leak
The material your flat roof is made of will have a direct impact on where you’re likely to find a leak. When hiring a contractor, it’s important to advise the professional of the material to confirm they have experience repairing this type of roof.
- Metal roofing systems. They will commonly have leaks due to puncture holes from debris or gaps formed by rust. Loose or missing screws and fasteners are another reason a metal roof may leak. Metal roofs are very durable and can last decades, but the cost to repair them can range from €500 to €800.
- Tiles. Roofs using tiles can make it difficult to locate the source of the leak because of the many different patterns that rainwater flows off of the tiles. Damaged tiles are common sources of roof leaks and it costs around €150 to €500 replace the defective tiles.
- Clay tiles. When used on a roof, they can become cracked and damaged. The valley on a clay roof is also prone to collecting debris and contributing to roof leaks. The average cost to repair a clay tile roof with new sections is between €250 and €750.
- Solar tiles. Solar tiles are used as a replacement for your existing roof tiles. Solar tiles are a newly developed product, so any issues with a roof leaking would need to be directed to the installer. Solar tiles are typically protected under a 25-year warranty, so any costs to repair them will usually be covered in the purchase price.
- Composite roof. A composite roof uses a few materials for installation including tar and slate. Leaks in these types of roofs can be caused by the tiles, joints, trim pieces, seals or flashing. The final cost to repair a composite type of roof depends on what exact materials were used for installation.
- Wood roof. The tiles or valleys on a wood roof may need repairing to fix any leaks. The cost to repair a wood roof with new tiles is about €600 to €900.
- Slate roof. Slate roof repairs for a leak are typically needed due to broken tiles or damaged flashing. The average cost to replace slate tiles is €150 to €250 while flashing repairs may cost upwards of €800.
Flat Roof Repairs and Replace Dublin
Torch-on felt is what covers most flat roofs and has come a long way in the last ten years. This is the go-to option, cheap and readily available, it’s usually applied in two or three layers. They can either have a granular finish or a smooth finish and this can be then painted with solar reflective paint. It usually comes with a materials guarantee of 10-15 years and costs about €55per sqm.
Another alternative is PVC, this is a single ply membrane of usually grey-coloured rubber is fixed to your timber base, making labour costs cheaper than the installation of a two-ply material. When its laid well it can looks very good, it usually costs 20-30 per cent more than a torch-on system and will come with guarantees of around 12-15 years.
Fibre Glass Roofing
Then there’s fibreglass flat roofing, its effectiveness is still a bit undecided but has a reputation of being durable. Its inflexible nature is not suitable for some situations, but advances in materials in recent years have made fibreglass roofing more reliable and very durable. Costs are around €70 per sq m on domestic-sized roofs and should be able to last for about 15-20 years. Read our advantages and disadvantages page
Zinc is growing in popularity and one of our favourites, it’s a slick, smooth, contemporary look that goes on in panels with a standing seam joining each panel. Its a very modern and durable look impressing the neighbours and visitors.
It is naturally resistant to corrosion, needs minimal to no maintenance due to its natural, self-protecting patina, and is extremely long lasting – 100 years-plus. It can come in a few grey, dark and silvery colours and will maintain its colour throughout its life.
Costs are about €120 per metre by the time up-stands, drips and fascias are taken into account. It is a nice advantage to be able to do your fascias, soffits and rainwater goods in the same material, giving nice continuity and consistency.
Copper has been the more traditional way to go. It is one of the few metals that occur naturally rather than needing to be extracted from ore, thus making it one of the earliest metals to be used.
The covering of choice for well-to-do buildings of the past. The gorgeous green patina it develops after years of oxidation has long been coveted by architects.
A truly beautiful natural product but unfortunately it comes with a truly heavy price tag. Expect to pay in the region of €130 per metre. Like zinc, it is extremely long lasting, around 100 years in this country.
Lead, another beautiful and traditional product, is hugely malleable, and mostly used on small areas, over bay windows for example. Cost would be similar to copper at €130 per metre and comes with a material guarantee of 50 years.