Flat Roofing FAQs

Absolutely we will. Our service incorporates surveying your roof to identify the problem, providing you with a detailed report including photographic evidence, and then working with you on a solution that fits the needs of the building and your budget so that the completed refurbishment roof will meet all your expectations. More on roof refurbishment ►

Our approved contractors are the only people fully trained and certified to install Bauder products as they provide the necessary skills, experience and business structure, and capability to deliver a project that will meet the demands of our stringent sign-off for a project so that we can issue a guarantee for the Bauder works on your project.

We post our vacancies on our website and you can view the latest positions here. Alternatively, you can contact our recruitment team via email and register your CV for future roles within Bauder.

Our ethos is to support you through your project from concept and design, to system selection, installation, inspection, and sign-off. We don't just supply products to a distributor, we work with you and care about the projects you deliver.

Yes. We hold ISO 14001 certification for our business practices as well as for our manufacturing production facilities. You can view our certificate here.

All the individual installers working on your project are required to display their approved operative badges at all times as these carry a photograph, name and the systems they are approved to install. You are completely within your rights to ask an operative to see their Bauder badge at any time and our site technicians will also check installer validity when they visit your project site. If an operative doesn't have their badge on them at the time, please contact our technical department, who will take a few details and let you know the status of the person you are calling about.

There are so many considerations to the correct selection of waterproofing that it can certainly be confusing. All the following elements impact on the options available to you; weight loading; thermal efficiency, wind uplift, finished build-up height, life expectancy, durability required depending on access levels and rooftop sited plant and equipment, and guarantee duration. The best way to ensure you have the correct system is to talk with your local Bauder contact. 
Arrange a meeting with your local area technical manager ►

There are two flat roof waterproofing options for projects that have a consideration for weight loading. Single ply uses synthetic membranes welded over the span of the roof and cold applied liquid utilises resins to create a homogenous waterproof layer. Both can be installed with insulation for a warm roof construction or without for a cold roof.
Learn more about single ply ►
Learn more about cold applied liquid ►

We have a network of approved contractors that are permitted to install our systems. Each company must possess the technical expertise and operational facilities to maintain an efficient and well-run site. Additionally, their installers are individually trained specifically in the application of our products, so you are ensured an expert installation that meets the criteria for our guarantee.

Our guarantees can cover all elements of the products that we sell, the design features we were involved in and can also include the installation of the system when carried out by one of our approved installers. We can provide a guarantee on all our projects and the duration reflects the system, its life expectancy and building requirements. It is recommended to discuss your required options with your local Area Technical Manager. 

Yes you can use our LiquiTEC in an inverted roof construction on both new build and refurbishment projects. You will need to use insulation manufactured from polystyrene as it possesses the specific properties that can cope with the environmental demands that will be placed upon it and of course the insulation will require a form of ballast either as a green roof, pebbles or paving. 
More on LiquiTEC ►

These are our patented range of products that have been developed to make installation faster, safer, simpler and more secure than previously possible. The patented technology features heat-activated and self-adhesive application. For example, the BauderTHERM DS1 DUO vapour barrier has a self-adhesive underside that adheres to the deck, colour coded laps that are welded to form a seal across the roof and an upper side with heat activated bonding stripes of bitumen that provide the adhesive required for installing the insulation.

We will arrange a convenient time with you to come and carry out a survey of your roof which will appraise all aspects of the current waterproofing. A core sample will help identify where the challenges are and additional technical diagnostics can pinpoint exactly where water ingress is occurring and the extent of the damage caused within the roofing system. Just give us a call, and we can arrange a survey to take place on your building by your local technical manager.
More information on site surveys ►

There are so many options available to you with regard to waterproofing selection that it's best to speak with your local technical manager who will meet with you and discuss your project, any historical problems with water ingress, your budget, and how the progamme of works can be scheduled as well as take you through all the benefits of each waterproofing system and how they map against your criteria.
Book a meeting with your local area technical manager ►

It's a method of testing for trapped water within a flat roof containing multiple layers. A moisture gauge is used to pinpoint the presence of dampness within the roof structure to depths of 300mm with the results delivered as a topographical map. This form of technical diagnostic is very useful in determining the extent of any water ingress and the remedial action required to reinstate the roof.
Read more information ►

Yes, as long as the additional weight loadings can be accepted by the building's structure. An important factor is to ensure that the life expectancy of the waterproofing system currently on or to be installed on the roof will match that of the PV array, otherwise you may find that the waterproofing system will need replacing earlier resulting in the complete removal of the array before works can commence to reinstate the integrity of the roof. The ideal time to add photovoltaics is to do it at the same time as refurbishing the waterproofing system.
More on retrofitting PV ►

Our network of contractors undergo a rigorous selection process and their installers are individually trained specifically in the application of our systems, so you are ensured an expert installation that meets the criteria for our guarantee. Only by monitoring all aspects of the installation, including workmanship can we ensure that the system for your roof meets our standards.

Our guarantees can cover all elements of the products that we sell, the design features we were involved in and can also include the installation of the system when carried out by one of our approved installers. We can provide a guarantee on all our projects and the duration reflects the system, its life expectancy and building requirements. It is recommended to discuss your required options with your local Area Technical Manager. 

We have the ideal solution. Our profiled metal overlay system is specifically designed for this scenario. The system comprises of profiled EPS insulation boards, which are manufactured to order so that the profiles match the existing roof sheets. The insulation is then sealed with a single ply membrane system to make the building watertight.
More on profiled roof overlay systems ►

PVC and FPO membranes are both heat welded at the seams giving superior protection against leaks, as the two sheets are fused together forming a complete and durable roofing membrane system. FPO membranes usually need lap preparation to remove surface static which can otherwise interfere with the weld.

PVC (polyvinyl chloride) and FPO (Flexible polyolefin) share common characteristics, neither can claim an overall superiority over the other. However particular characteristics of each of these two polymers can be exploited by the specifier to enhance the specification of their single ply roofing system.

The manufacturing formulation of PVC roof membranes gives them good inherent properties (i.e., chlorine) in relation to fire performance, although additives are required to ensure system passes for TS 1187 B_ROOF(t4).

FPO membranes also require additives to enhance their fire performance.

Bauder has completed numerous Single Ply system fire performance tests to B_ROOF(t4) at both zero and 45 degrees. A selection of these is detailed in the BBA certificates. For a full list contact the Bauder Single Ply Product Manager.

• Thermofol Light Grey 7035
• Thermofol Blue Grey 7031
• Thermofol Anthracite 7016
• Thermofol Walkway 7012
• Thermoplan Pearl White 1013
• Thermoplan Silver Grey 7001
• Thermoplan Walkway 7016

Following trades on a finished Bauder roof should always make provision for protection of the waterproofing. The most common protection being in the form of BauderGREEN FSM 600 Protection Mat, followed by a layer of plywood. This should provide adequate protection for the waterproofing whilst following trades carry out their remaining works.

Ensure plant or equipment that has been introduced to the roof are sited on suitable isolated slabs, with additional surface protection beneath. Ensure any fixings that may have been used to secure them, do not penetrate the waterproofing.

Once works are finished, clear all debris from the roof surface, rainwater outlets, chutes, gutters, etc. Debris must be removed from the roof and not simply flushed down rainwater pipes. Any waterproofing damage caused after completion of the original installation may invalidate the guarantee.

A high-performance stainless-steel outlet with factory installed PVC/FPO membrane flange, supplied with an O-ring and a wire ball leaf grate.

Available in various dimensions to meet project requirements:

• DN70 (to suit 75mm-97mm rainwater pipe) – 2.98l/s flowrate
• DN100 (to suit 110mm-128mm rainwater pipe) – 3.94l/s flowrate     
• DN150 (to suit 160mm-178mm rainwater pipe) – 6.76l/s flowrate       
  @35mm head of water with leafguard

A rigid PVC/FPO rainwater outlet enabling thermofol/thermoplan membrane to be welded to the flange plate, whilst UV stable throughout.

• DN70 (to suit 75mm-97mm rainwater pipe) – 4.40l/s flowrate
• DN100 (to suit 110mm-128mm rainwater pipe) – 6.00l/s flowrate     
• DN150 (to suit 160mm-178mm rainwater pipe) – 7.50l/s flowrate      
  @35mm head of water with leafguard

Find out more about our outlets on our Products page.

The maximum pitch of a single ply roof that BauderSOLAR can be installed on is 10 degrees.

The maximum pitch that a single ply roof should be installed is 70 degrees. The reason for this is that the fire test CEN/TS 1187: 2012 Test 4 External Fire exposure provide two options of incline. A flat test would cover a roof pitch between 0 and 10 degrees. The second sloping gradient test is at 45 degrees, and this covers a roof pitch between 10 and 70 degrees.

Both membranes have characteristics that provide benefits to the client. Approximately 75% of the UK Single Ply market is PVC, FPO is less than 5%, therefore most operatives are more used to welding PVC.

FPO is less forgiving than PVC in its welding, which can lead to poorly welded seams. Therefore, operatives need to be specifically trained to install FPO membranes. PVC membranes typically have a generic design, making them easier to weld. FPO membranes require more time to weld with a handheld hot air gun, increasing the labour costs.

Most FPO membranes are lighter in colour (due to thermal expansion issues). PVC is now widely used in dark grey colour in the UK. Decorative profiles are not an option with FPO due to thermal expansion issues. FPO is a naturally flexible membrane as it has no plasticisers. The membrane will have an exceptional life expectancy if buried, removing UV degradation.

FM approvals is the independent testing arm of international insurance carrier, FM Global. FM approvals uses scientific research and testing to ensure products conform to the highest standards for safety and property loss prevention. Products that pass get the ‘FM Approved’ mark. Bauder has numerous different single ply mechanically fastened and ballasted assemblies that have achieved an FM approval. For more details, please contact Bauder’s Single Ply Product Manager.

All 1.5mm & thicker Thermofol & Thermoplan membranes have FLL root barrier certification ensuring they are suitable for green roof systems.

There are various considerations depending on specific project requirements:

Mechanical fastening may be suitable if the substrate is metal or plywood rather than a concrete deck. However, fasteners will be seen through a metal or plywood deck, which might not be suitable if the underside of the deck is exposed.

In general, mechanically fastened systems with a polyethylene AVCL are cheaper than a bituminous AVCL and synthetic fleece-backed membrane with adhesives. However, a bituminous AVCL (2.5mm plus thickness) will provide a building with a temporary waterproofing layer, which may benefit the project’s installation programme.

Aesthetics are an important consideration. Mechanically fastened systems can be more susceptible to thermal movement than adhered membranes and may flap in high wind loads, proving an undesired visual effect.

An adhered system may not be suitable in coastal areas or high buildings where wind loads are higher than usual, therefore a mechanically fastened solution may be the only option. A project specific wind load calculation will determine whether adhered is possible.

A hybrid build up is a suitable solution in some situations. Mechanically fastening insulation through a polyethylene AVCL keeps costs lower than employing a bituminous AVCL. Adhering a fleece-backed membrane will enhance the roofs aesthetics.

Acoustics and air leakage may be additional considerations; often a fully adhered solution will be more suitable in these situations.

SPRA (Single Ply Roofing Association) is the trade association representing the UK’s single ply roofing industry. Their mission is to achieve growth and sustainability in all sectors of the single ply roofing industry by raising the awareness of single ply technology, its value and ensuring manufacturing and installation standards remain high.

SPRA members are actively involved in the monitoring, development and reporting of cutting-edge technologies to improve single ply products, installations and aftercare. 
Bauder is a Manufacturer Member of SPRA and Nigel Blacklock, Bauder Technical Director is Chair of the SPRA Technical Committee, and also a member of the SPRA Council.

Download a copy of The SPRA Design Guide at www.spra.co.uk

Single Ply membranes are strong and flexible sheets composed of synthetic polymer, between 1.2 and 2mm in thickness. When combined with an air and vapour control layer, insulation and a continuous support they form a complete and durable roof system.

• Lightweight assemblies, suitable for new build or refurbishment projects
• Simple and fast installation process
• Provides desirable aesthetics
• Energy efficient with heat reflective properties
• Flame free installation
• A removed single ply flat roof can be recycled
• Resists UV damage

This will depend upon several factors:

• Type of single ply membrane (PVC or FPO)
• Environment (buried, exposed, orientation, location)
• Membrane thickness
• Most membranes have a life expectancy of between 25 and 40 years

LiquiTOP PU and LiquiTEC PMMA systems have many common features including, cold application methods, seamless waterproofing and adaptability to intricate roof details. Neither can claim an overall superiority over the other, however particular characteristics of each of these two polymers can be exploited by the specifier to enhance the specification of their waterproofing system.
 
LiquiTEC poly methyl-methacrylate (PMMA) liquids are two component materials and require a catalyst to be thoroughly mixed into the resin to form a seamless waterproofing membrane. This curing mechanism leads to the liquid rapidly curing which is an advantage where quick access to roofs and balconies is required. The system is reinforced with a polyester fleece and is applied wet on wet, meaning that the full system thickness is applied in one operation, which again makes it quicker to install to smaller areas. The two component nature of the liquid and the polyester fleece makes these systems more complicated for the installer to apply on site.
 
LiquiTOP polyurethane (PU) liquids are single pack materials and utilise a moisture triggered curing mechanism to form a seamless waterproofing membrane. This curing mechanism requires some atmospheric or substrate moisture to initiate the curing process, making it more moisture tolerant. The system is reinforced with a glass fibre mat and is applied wet on dry. Although this means that each coat needs to be allowed to cure before the next coat is applied, it also means that a larger area can be treated with the first/embedment coat, which allows a greater area to be temporarily waterproofed. The single component liquid and the conformable glass fibre mat make it easier for the installer to apply on site, especially over rounded of irregular details.

LiquiTOP PU and LiquiTEC PMMA systems can be applied to most substrates found in flat roofing applications including:

• Reinforced bitumen membranes (RBM)
• Single Ply
• Asphalt
• Liquid applied membranes (LAM)
• Timber
• Concrete
• Brick/Block/Masonry
• Metal

Some substrates will need to be primed as follows:

LiquiTEC PMMA

• Mineral surfaced RBM – None
• Exposed Bitumen – LiquiPRIME 1
• PVC Single Ply* - None, but clean with PMMA Cleaner
• FPO Single Ply* - Abrade and may need PMMA Cleaner or Special Primer 610
• EPDM* – Special Primer 610
• Asphalt* – LiquiPRIME 1
• LAM* - None, but clean with PMMA Cleaner
• Timber – LiquiPRIME 1
• Concrete – LiquiPRIME 2
• Porous Concrete – Cryl 287 Primer
• Brickwork – LiquiPRIME 2
• Metal – Clean with PMMA Cleaner

LiquiTOP PU

• Mineral surfaced RBM – None
• Exposed Bitumen – LiquiTOP General Purpose Primer
• PVC Single Ply* - LiquiTOP PVC Primer
• Asphalt* – None
• Absorbent asphalt* – LiquiTOP General Purpose Primer
• LAM* - LiquiTOP Reactivation Primer
• Timber details – LiquiTOP General Purpose Primer
• Concrete – LiquiTOP General Purpose Primer
• Brickwork – LiquiTOP General Purpose Primer
• Metal – LiquiTOP Epoxy Primer

*Always do an adhesion test

Substrates must be clean, dry and free of dust and any other contaminants. Any algae or moss must be sterilized with a solution of diluted bleach. Proprietary biowash solutions are also available. Existing roofs must be swept clean and then power washed to remove dirt. Chippings must be scabbled off before power washing. Metals must be rust/oxidisation free and be free of paint or other coatings. Abrade surfaces to give a key. In all cases, make sure the substrate is dry.

These are fundamentally the same but with slightly differing properties. LiquiDEK is the roofing product and flows to give a flat surface. LiquiDETAIL is for details, it has better thixotropic properties which means it holds vertical upstand details better. LiquiBALKON is the reinforced balcony and walkway product. It is tougher and flows well to give a flatter surface than LiquiDEK.

The unreinforced balcony and walkway system can only be used on concrete or asphalt cantilevered or inset balconies i.e. they are stable and not over occupied spaces.

Cracks in asphalt must be raked out and cleaned before priming with LiquiPRIME 1 and then filling with LiquiPASTE or LiquiPASTE Mortar. Blisters must only be removed by cold work techniques, usually with a grinder. Once removed the exposed deck and surrounding asphalt will need to be primed and the hole filled flush with LiquiPASTE Mortar.
 
For filling larger horizontal or vertical voids 5-30mm deep, LiquiPASTE Mortar can be used. LiquiPASTE Mortar is made from catalysed LiquiPASTE mixed with Bauder Quartz 0.4-1.2mm in a ratio of 1:1.

LiquiPAVE RF Mortar is made from LiquiPAVE RF mixed with Bauder Quartz 0.4-1.2mm as follows:

LiquiPAVE R (1 part)
Catalyst (4% average)
LiquiPAVE F (2.3 parts)
Bauder Quartz (2 parts)
 
The LiquiPAVE R needs to be catalysed before the LiquiPAVE F is mixed in and then the Bauder Quartz is added and mixed in. It is capable of filling horizontal voids and deflections of around 3-50mm e.g. low spots in a zero falls concrete deck.

The LiquiDEK roof system can be used for inverted roof applications with zero falls and this is detailed in the BBA Certificate. Note that the definition of zero falls are falls less than 1:80 and that the finished roof surface must not have back falls. For exposed waterproofing applications, the roof should achieve a minimum 1:80 fall.
 
For exposed balcony systems, the surface must always be to falls as standing water will be a slip hazard, especially if it freezes.

LiquiTOP roof systems have been designed and have BBA certification for use in exposed roofing situations and should be use on roofs to falls to avoid unsightly ponding on the finished roof.

Tiles can be used as the wearing surface for the LiquiTEC reinforced balcony and walkway system. To provide a key Bauder Quartz is bonded to the waterproofing layer either in LiquiPAVE RF or LiquiBALKON. The tiles are then bonded to the quartz surfacing. Any appropriate exterior tile adhesive can be used as long as it is not solvent-based.

The LiquiTOP PU products are all available in two shades of grey: Dark Grey (approximately RAL 7011) and Mist Grey (approximately RAL 7040). Both colours are interchangeable as embedment and top coats and are UV stable giving a waterproofing membrane that is UV stable throughout. For aesthetic reasons we usually suggest that Dark Grey is used as the top coat.

The LiquiTEC range of products are all provided in various shades of grey:

• LiquiDEK, LiquiDETAIL and LiquiFIBRE are all approximately RAL 7031 (Blue Grey)
• LiquiBALKON is approximately RAL 7032 (Pebble Grey)
• LiquiFINISH is available in RAL 7031 (Blue Grey), RAL 7030 (Stone Grey) or RAL 7043 (Traffic Grey)

The main use for LiquiFINISH is as a sealer coat to the exposed LiquiTEC balcony and walkway finishes or maintenance walkways on LiquiTEC roof and terraces where it is applied over the quartz.

It can also be used if the colour of a finished LiquiDEK roof needs to be changed for aesthetics. LiquiFINISH is available in RAL 7031 (Blue Grey), RAL 7030 (Stone Grey) or RAL 7043 (Traffic Grey). Other colours are available, but they often have long lead times. AL 7043 (Traffic Grey). Other colours are available, but they often have long lead times.

Its main advantage, apart from being extremely cost effective as a waterproofing system, are that it forms a 100% bond to the deck eliminating the possibility of water tracking between it and the deck. It is monolithic once complete. No laps!

True Hot Melt Systems utilise a Polyester Reinforcement Fleece between 2 no. 3mm layers of 790-11 Hot Melt compound. Research has shown that the best way of eradicating the effects of pin-holing is to employ a 2-layer reinforced system.

790-11 is a fully bonded system, which limits water migration even if damage occurs. 790-11 allows a building or structure to be made watertight in a hurry.

There are many types of substrates that 790-11 can be installed onto including:

• In-Situ Concrete
• Lightweight Concrete in Structural Metal Trays
• Pre-Cast Concrete Planks
• Brickwork
• Concrete Blocks
• Exterior Grade Ply
• OSB3
• Cement Bonded Particle Board
• CLT Panels
• Metal Plate
• Bituminous Membranes

Surface Applied Curing Compounds are sometimes used by the In-Situ Concrete Deck installer to aid and protect the curing process. Some of these compounds have a detrimental effect on the bond of 790-11 to the deck. Bauder should always be informed if these compounds have been employed for comment on their suitability.

The industry recognised test within the UK is the Peel Bond Test. At around 14-21 days after in-situ concrete has been poured we use the Peel Bond Test to ascertain whether the concrete has cured enough to provide a good bonding environment with our 790-11. The Peel Bond Test mirrors the specification. A layer of primer (Polymer or bituminous) is laid on a clean concrete area. Once dry a layer of 3-4mm of 790-11 is installed over the top with a patch of protection sheet laid into it when warm.

The size of the test area should allow for 2 tests. One on day of installation and one 24 hours later.

Cut two sides of a triangle through the protection sheet down to the deck. Pull the sample from the point. If the sample sticks to the protection sheet and not the deck this is an adhesive failure (FAIL), if the sample sticks to both the deck and underside of the protection sheet but pulls apart by the product parting this is called a cohesive failure (PASS).

If you gain a pass wait 24 hrs to do a second test. If the pass is replicated you are good to go.

Other methods that can be used are:

• Moisture Meters – These can measure the moisture content remaining within the deck hydration process. 4 to 5% at 75% RH would be a pass target
• Plastic Sheet Method – This can be used as a quick guide to see whether a full-blown Peel Bond Test is worth carrying out. Basically, a plastic square is taped to a dry deck, sealing it. Wait 16-24 hours and peel back. Any moisture on the deck or underside of the plastic would indicate that too much moisture is still present within the in-site concrete for successful adhesion of the 790-11

It can, as detailed in our current BBA Certificate. It must be remembered that zero falls is a completed roof deck with a fall of 0 to 1:80. There should be no back-falls.

Our BBA Certificate gives our 790-11 Waterproofing System will provide an effective barrier to the transmission of liquid water and water vapour for the design life of the roof in which it is incorporated.

The following items should be considered when specifying: 

a) Wind Uplift – In areas of high risk, tall buildings etc. we would recommend a wind uplift calculation is performed to confirm ballasting requirements

b) Flotation – all EPS or XPS inverted insulation needs to be ballasted to prevent floatation

c) UV degradation - EPS or XPS inverted insulation should be covered by its WFRL and subsequent surfacing as soon as possible after installation

d) Fire Risk - EPS or XPS inverted insulation should be covered by its surfacing as soon as possible to prevent any risk of fire at construction stage

e) U Values – Care must be taken with u value comparisons between different manufacturers inverted insulation. Design lambda values can vary making thickness comparisons tricky. Preference would be that each project has a calculation carried out to confirm thickness against specifier target u value. Always check to see whether insulation is incorporated to the deck underside as this could impact on the thickness requirement for the inverted insulation above deck. If requesting u value calculations, advise where in the country the project is located (post code required), as rainfall levels can change based on location

As a minimum, an outlet with a clamping ring should be used. Our Bauder Hot Melt Compact Vertical Outlets are ideal or any cast aluminium outlet with clamping ring can be used. We do not guarantee the seal to non-Bauder outlets.

Inverted roofs are designed with the waterproofing layer beneath the insulation. Insulation boards are loose-laid on top of the membrane and then weighted down with paving slabs, gravel ballast or a green roof construction. As such the insulation needs to be suitable for the exposure it is now subject to.  Polystyrene boards either extruded or expanded are suitable as they are impenetrable to water, resistant to rot and decay and have high compressive strength.
More on inverted insulation ►

It's a vacuum insulation panel (VIP) which is utilised in areas with limited height. The board is constructed from a Pyrogenic Silica core, surrounded by a multi layer high-barrier film with the air then removed to create the vacuum. This is then protected by a 3mm rubber crumb base and a surface of 17mm PIR. It is extremely thermally efficient with the vacuum core achieving a thermal conductivity of 0.0072W/mK.
More on VIP insulation ►

A vacuum insulation panel sounds like the solution you need. It's designed particularly with the challenge of limited installation height in mind and therefore ideally suited for roofs as well as balconies and terraces.
More on VIP insulation ►

All insulations can achieve 0.18, the difference between them is the thickness required and the weight loading of each type.  For instance a Bauder foil-faced PIR board will be 120mm thick and weigh 3.6 Kg/m²; BauderJFRI expanded polystyrene will be 200mm thick and weigh 7Kg/m² and BauderROCK mineral fibre insulation will be 200mm thick and weigh 27.2 Kg/m². Our technical team can help you with heights and weight loadings should you need assistance, just give us a call.
More on insulations ►

Our flatboard PIR is faced with a mineralised glass fibre and is specified when a torch-bonded underlayer is to be used beneath the cap sheet. Our FA-TE board is faced with aluminium foil which further increases thermal efficiency and can only be used with self-adhesive underlayers. As a comparison a 120mm board of FA-TE provides the same thermal value as 140mm of BauderPIR flatboard.
More on PIR insulation ►

When deciding on a deck, thought should always be given to the loading it will have to take. It is possible to use a concrete deck with a wood float finish, metal or timber (plywood should be an exterior WBP grade). If you are considering an alternative deck, please give us a ring and we will confirm suitability with you.
More about weight loadings of a green roof ►

The lightest weight green roof is the XF 301 sedum blanket system which is a pre-cultivated 'turf' comprised of low-growing, low-maintenance succulent plants (sedums) that is rolled out directly on top of the root-resistant or protected waterproofing. It only has a saturated weight loading of 44Kg/m² making it ideal for new build or retrofitting to a current building. 
More about sedum blanket green roofs ►

All green roofs require a minimum of two inspections a year to ensure that the rainwater outlets are maintained. An intensive green roof will need the regular care associated with the garden planting scheme and landscaping. An extensive green roof will only need minimal maintenance to ensure that any unwanted species do not become established. 
More information on maintaining a green roof ►

A substrate is a lightweight alternative to soil which reduces weight loadings on the green roof whilst still providing a base for the plants and vegetation to grow in. It doesn't hold nutrients as efficiently as soil and so annual applications of granular fertiliser are often required to sustain the plants. 
More information on green roof components  ►

A vegetation barrier is created using washed round pebbles and is primarily incorporated to prevent vegetation encroaching on elements such as rainwater outlets and to provide wind uplift resistance at roof perimeters. 
More information on functions ►

You don't have to choose between the two technologies, you can have both in an integrated solution. A BioSOLAR system incorporates a water retention board in the mounting system and uses the substrate and vegetation as the ballasting mechanism for the installation method. A key element of a combined system is that the PV panels are elevated to allow for vegetation growth without blocking light to the modules. 
More on BioSOLAR ►

This is dependant on the depth of substrate and the planting scheme, though a typical guide for a roof garden ustilising 200mm of substrate would be 270Kg/m². The system summary PDF covers the components typical and the associated weight loadings.
More on a generic roof garden build up ►

It's a pre-cultivated vegetation mat incorporating a mix of established sedum plants that is supplied in a 'turf' format to be rolled out onto a roof giving instant coverage. 
More on sedum roofs ►

This will depend on what biodiversity species you need to encourage on the roof and the plants stated in the report. If the requirement is more generic, you can consider a wildflower blanket or seed mix which will satisfy the requirements of BREEAM or planning. 
More on biodiversity green roofs  ►

Tapered insulation is one of the most cost-effective methods of introducing a fall to a flat roof. It is also significantly lighter than screed to falls solutions and does not suffer from lengthy drying times.
More on tapered insulation ►

There are a lot of points to consider, and the place to start is to establish what finish the green roof is to have. What is it to look like and who will access it?  Do you need to meet any planning conditions and would you also like to add PV to the roof?
Learn more about the factors to consider ►
Book a meeting with your local area technical manager ►

Absolutely. Just contact our technical team for advice on how to create the detail for your project.

We have BBA certification on a number of our waterproofing systems, including:

Bituminous membrane systems ►
Single ply waterproofing ►
Cold applied liquid ►
Hot melt waterproofing ►

You have a couple of choices with regard to insulation type and waterproofing systems. Our bituminous, single ply and cold liquid applied will all work within your height constriants and can be used in warm roof designs. Your choice of insulation is a little more restricted and will be primarily between PIR flatboard or foli-faced PIR FA-TE. The exact combinations of both waterproofing and insulation can be determined by what needs the building has for durability, weight loading and life expectancy.
More on profiled roof overlay system ►

We have a solution that combines the technologies enabling both to be installed without one compromising the other. Bauder BioSOLAR is an integrated solution where the anchor board for the PV mounting rails is ballasted by the substrate and vegetation of the extensive/biodiverse green roof. The PV modules are raised above the vegetation so that there is ample growing room for the plants so that they don't shade the modules and light and moisture can reach beneath the panel to support the plants.
More about BioSOLAR ►

The units can be installed on roof pitches up to 10° on single ply & up to 5° on Bituminous membranes. The BioSOLAR system can be installed on roofs up to 3°.

No. We are not able to verify or warranty the bond or ballast requirements to non-Bauder roof systems. For BioSOLAR, we need to ensure that our substrate is used as this is the ballast material. If an alternative substrate was used this could erode allowing the modules to lift & we would be unable to provide windload calculations.

• Bauder BioSOLAR is designed to be used with our Biodiverse green roof solutions
• BauderFlora 3 is specifically formulated to provide a biodiverse planting mix to meet most UK local biodiversity action plans
• If your scheme has specific planting requirements please contact our technical team to discuss options

The exact system weight will vary depending on ballast requirements and system specification but the average BioSOLAR solution will weigh approximately 175kg/m²*. *Weight includes waterproofing membranes, insulation, green roof system and solar modules.

The forces exerted would never be strong enough to damage the membrane if correctly installed and designed as per our layout.

We will work with you and discuss the roofing project, your budget and how the roof array can be designed to maximise your benefits from the use of PV.  More ►

This pitch is a factor in system efficiency. The most efficient angle in the UK is 30-35° but as you can fit more panels onto the roof at 12° you will achieve a higher output per m². 12° also reduces wind uplift making the system much cheaper to install and the low profile can reduce issues with planning.

The exact weight varies depending on the module choice but the maximum weight is 12.5kg/m².

Unless it is specifically designed for green roofs then it is likely to fail from both a green roof and solar PV perspective.

• The panels are all MCS accredited
• Flat roof mounting units are not currently included in MCS certification

• BioSOLAR can be used on substrate based extensive and biodiverse green roofs
• Bauderflora 3 seed mix is specifically designed to work with BioSOLAR applications

Yes – BioSolar is universal for framed modules up to 1.9m length.

Installing as an East/West orientation will both reduce windload impacts and therefore costs of mounting system/ballast. It also allows for more of the green roof to receive direct sunlight which leads to better vegetation cover.

Modules are installed at 10° pitch to reduce windload impacts and therefore ballast requirements.

•    All bituminous
•    All Thermoplan
•    1.8mm and 2mm Thermofol mech fixed – all colours
•    1.5mm fleece backed Thermofol fully adhered – all colours

If a roof leak is identified then Bauder will require the solar PV system to be removed, at the client’s cost, by the client before we can attend site or explore the issue.

Outputs will vary depending on a number of factors but the following can be used as a general rule of thumb:

• BauderSolar -1kWp = approx. 8sqm of ‘clear’ roofspace
• BioSolar – 1kWp = approx 10sqm of ‘clear’ roofspace.
• NB – a 250sqm roof will not provide 25kWp due to avoidance of perimeter windload zones/SVPs/shading of parapets etc.

Yes, as long as the additional weight loadings can be accepted by the building's structure. An important factor is to ensure that the life expectancy of the waterproofing system currently on or to be installed on the roof will match that of the PV array, otherwise you may find that the waterproofing system will need replacing earlier resulting in the complete removal of the array before works can commence to reinstate the integrity of the roof. The ideal time to add photovoltaics is to do it at the same time as refurbishing the waterproofing system. 
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When modules are in shade their performance can be affected. If you install a power optimiser each individual module is monitored to determine the maximum power point (MPP) so that any shading does not impact on the entire string. This monitoring system can give up to 25% more output from an array. 
More on power optimisation ►

A distinctive element of our solar system for flat roofs is that the installation doesn't require any penetrations of the waterproofing or roof deck, even in a non-ballasted arrangement. Our system utilises membrane-to-membrane fixing techniques to secure the mounting units to the roof. The weld areas create a very stable base for the units and PV modules, even in areas at risk of high wind uplift. 
More on our BauderSOLAR system ►

We have a solution that combines the technologies enabling both to be installed without one compromising the other. Bauder BioSOLAR is an integrated solution where the anchor board for the PV mounting rails is ballasted by the substrate and vegetation of the extensive/biodiverse green roof. The PV modules are raised above the vegetation so that there is ample growing room for the plants so that they don't shade the modules and light and moisture can reach beneath the panel to support the plants.
More about BioSOLAR ►

You would need 322 panels with 310Wp capacity rating, all orientated at due south. This number of panels would require 966m of flat roof without any areas of shading. We can produce calculations and an array layout for you if you need assistance. Call our technical team for more information.

The ideal siting for a PV array on a flat roof is with a due south orientation, on an area without possible shading from overhanging trees, other buildings or lamp posts etc.