Tough 3kg/m² SBS elastomeric venting underlay. Semi-adhesive.

Product variations:
BBA 10/4787 (1) BBA 10/4787 (1)
Bituminous SBS modified membrane reinforced with a non-woven polyester felt. Combined underlay and venting membrane for partial-bond applications finished with easy peel polyethylene film finish.


  • Bottom sheet in bilayer membranes for waterproofing roofs with semi-adhered heavy protection.
  • Bottom sheet in bilayer membranes for waterproofing semi-adhered self-protected roofs.

Advantages & Benefits

  • High movement capability.
  • Modified with SBS polymers, it achieves much higher performance in behavior at high and low temperatures, elasticity and resistance to aging, which leads to improved durability of the membrane .
  • Helps to increase the durability of the sheet.
  • It retains its properties better over time.
  • Good anti-piercing protection from mechanical damage.
  • High tensile strength and high elongation at break.
  • High resistance to tearing.
  • High resistance to static and dynamic piercing.
  • Rot-proof.
  • Improves the performance of mechanically fastened sheets by providing a high wind suction resistance value and optimising the density of fastenings.
  • Very stable in the long term.

Instruction for Use

  • The substrate surface must be solid, uniform, smooth, cleaned, dry and free from foreign bodies.
  • It is placed on the support by mechanical fasteners spaced approximately 20 cm. maximum.
  • Danopol range is welded to the colaminated profile by hot air, resulting in high reliability welding and finish.

Indications and Important Recommendations

  • Store in a dry place, protected from rain, sun, high and low temperatures.
  • It should be kept in the sun for as short a time as possible to protect it from UV rays.
  • In case of new construction and renovation, possible chemical incompatibilities with APP plastomer-modified bitumen sheets shall be taken into account.
  • In case of refurbishment, chemical incompatibilities with old waterproofing systems consisting of PVC membranes, modified tar-based mastics or any other, shall be taken into account, and it may be necessary to remove them completely or to use suitable separating layers.
  • If it is necessary to adhere to metallic or slightly porous elements, a bituminous primer (IMPRIDAN 100) shall be applied to the entire surface to be welded beforehand.
  • Not suitable on flat roofs as permanent waterproofing layer.
  • In case the substrate is a thermal insulation board, the compatibility between the two materials shall be verified.
  • During cold weather, the substrate, if uncombustible, can be heated with the torch or other means.
  • This product is part of a waterproofing system, so all the documents referred to in the Danosa Solutions Manual must be taken into account, as well as all the regulations and legislation that must be complied with in this respect.
  • Exposure to the sun can make it difficult to remove the release film. The temperature of the membraneduring installation must not exceed 45°C.
  • It must not be installed when the ambient, product or substrate temperature is below +10°C.
  • There is no chemical incompatibility between the Danosa range of SBS elastomeric bitumen and plastomeric bitumen sheets.
  • Not suitable as cap sheet on green roofs; use GARDEN variant.
  • To join the transverse overlap at the ends of the rolls, it is necessary to preheat the transverse edge of the bottom sheet in a strip of 8-10 cm, remove the protective polyethylene film in the bituminous mass and then adhere the end of the next piece.
  • Possible incompatibility between thermal insulation and waterproofing shall be checked.
  • A separating layer (DANOFELT or DANODREN) must be laid before laying the heavy protection (paving, gravel, topsoil, etc.), except in the case of waterproofing under tiles.
  • Polyurethane foam shall not be sprayed directly on top of the waterproofing without the use of a suitable separating layer (geotextiles, mortar layers, polyethylene film, etc).
  • If expansion that could affect the sheet is expected, a separating layer shall be used between the sheet and the extruded polystyrene insulation boards, so that each product expands independently.

Maintenance Recommendations

  • Please refer to DANOSA UK Technical Statement ‘Flat Roof Waterproofing – Cleaning and Maintenance Recommendations’

Handling, storage and preservation

  • Before moving the pallet, check the condition of the shrink-wrap and reinforce if necessary.
  • The product should be kept in the sun for the shortest time possible to protect it from UV rays
  • The product must be stored in a dry place protected from rain, sun, heat and low temperatures.
  • The product must be stored horizontally.
  • The product will be used on a first-come, first-served basis.
  • In cold weather, it is advisable to slightly heat the support with the blowtorch.
  • This product should not be installed when the ambient, product or support temperature is below +10ºC.
  • This product is not toxic or flammable.
  • Exposure to the sun can make it difficult to remove the release film. The temperature of the sheet during installation must not exceed 50ºC.
  • Waterproofing work must not be carried out when weather conditions may be detrimental, in particular when it is snowing or there is snow or ice on the roof, when it is raining or the roof is wet, surface dampness >8% according to NTE QAT, or when a strong wind is blowing.
  • Pallets shall not be stacked on top of each other.
  • For high storage, the racks must have three cross members, or braces under the wooden pallet skids.
  • For handling with a crane, use a protective net as indicated on the pallet label.
  • Danosa recommends consulting the safety data sheet for this product, which is permanently available at, Knowlegde Portal, or it can be requested from our Technical Department.
  • In all cases, the Occupational Safety and Hygiene standards, as well as the standards of good construction practice, must be taken into account.
  • For further information, please contact our Technical Department.


  • The information contained in this document and any other advice provided, are given in good faith, based on DANOSA's current knowledge and experience when products are properly stored, handled and applied, in normal situations and in accordance with the recommendations of DANOSA. The information applies only to the application (s) and the product (s) to which reference is expressly made. In case of changes in the parameters of the application, or in case of a different application, consult the DANOSA Technical Service before using the DANOSA products. The information contained herein does not exonerate the responsibility of the building agents to test the products for the application and intended use, as well as their correct application in accordance with current legal regulations. The product images used in our communications are indicative and may differ slightly in color and aesthetic appearance in relation to the final product.Orders are accepted in accordance with the terms of our current General Sales Conditions.DANOSA reserves the right to modify, without prior notice, the data reflected in this documentation.Website: E-mail: Telephone: +34 949 88 82 10


  • Length (cm): 700
  • Width (cm): 100
  • Thickness (mm): 2.5
  • Product code: 141287

Technical Data

Concept Value Standard
Mass per unit area (nominal) (kg/m²) 3 -
Durability flexibility -5 ± 5 -
Creep durability (ºC) 100 ±10 UN-EN 1110
Elongation at break longitudinal (%) 45 ±15 UNE-EN 12311-1
Elongation at transverse break (%) 45 ±15 UNE-EN 12311-1
Water vapour resistance factor (μ) 20.000 UNE-EN 1931
Low temperature flexibility (ºC) <-15 UNE-EN 1109
Reaction to fire E UNE-EN 11925-2; UNE-EN 13501-1
Resistance to static loading (kg) >15 UNE-EN 12730
Resistance to root penetration No pasa UNE-EN 13948
Longitudinal tensile strength (N / 5cm) 700 ± 200 UNE-EN 12311-1
Transverse tensile strength (N / 5cm) 450 ± 150 UNE-EN 12311-1
Longitudinal resistance to tearing (nail shank) (N) NPD UNE-EN 12310-1
Transversal resistance to tearing (nail shank) (N) NPD UNE-EN 12310-1
Resistance to impact, A (mm) >900 UNE-EN 12691
Joint Strength: Welding Shear 450 ±150 UNE-EN 12317-1
Hazardous substances PND -
Resistance to root penetration No pasa UNE-EN 13948

Addtitional Technical Data

Concept Value Standard
Adhesion of granules (%) NPD UNE-EN 12039
Creep resistance at high temperatures (ºC) >100 UN-EN 1110

Standards and Certification

  • In accordance with the UNE-EN 13707 standard ‘Flexible sheets for waterproofing - Reinforced bitumen sheets for roof waterproofing - Definitions and characteristics’.
  • In accordance with the UNE-EN 13969 standard for ‘Flexible sheets for waterproofing - Bitumen damp proof sheets including bitumen basement tanking sheets - Definitions and characteristics’.
  • Complies with CE marking requirements.
  • DTA "ESTERDAN Adhésif".

Environmental Information

Concept Value Standard
Post-consumer recycled content (%) 35 -
Manufactured in Fontanar - Guadalajara (España) -