Sarnafil® AT-25
Polymeric FPO membrane for mechanically fastened and ballasted roof waterproofing
Sarnafil® AT-25 (thickness 2,5 mm) is a multi-layer synthetic membrane based on flexible polyolefines (FPO) with an internal fabric and backing according to EN 13956. Sarnafil® AT-25 is a hot air weldable roof membrane formulated for direct exposure and designed for use in all global climatic conditions.
- Resistant to UV exposure
- Resistant to permanent wind exposure
- Resistant to all common environmental influences
- Hot air weldable
- No open flame equipment required
- High dimensional stability from glass fleece inlay
- Resistant against impact load and hail
- Resistant to mechanical influences
- Resistant to root penetration
- Compatible with old bitumen
Usage
Waterproofing membrane for:- Mechanically fastened roofing systems
- Loose laid ballasted roofs with different ballast materials (e.g. gravel, concrete slabs)
- Green roofs (intensive, extensive)
- Utility roofs
- Inverted roofs
- Terraces with pedestrian traffic
Advantages
- Resistant to UV exposure
- Resistant to permanent wind exposure
- Resistant to all common environmental influences
- Hot air weldable
- No open flame equipment required
- High dimensional stability from glass fleece inlay
- Resistant against impact load and hail
- Resistant to mechanical influences
- Resistant to root penetration
- Compatible with old bitumen
Packaging
Sarnafil® AT-25 standard rolls are wrapped individually in a blue PE-foil.
| Packing unit | Refer to price list |
| Roll length | 10,00 m |
| Roll width | 2,00 m |
| Roll weight | 52,00 kg |
Refer to current price list for packaging variations.
Colour
| Surface | matt |
| Colours | |
| Top surface | window grey (~RAL 7040) |
| Bottom surface | dark grey |
Product Details
ENVIRONMENTAL INFORMATION
- Conformity with LEED v4 SSc 5 (Option 1): Heat Island Reduction - Roof (only traffic white)
- Conformity with LEED v4 MRc 3 (Option 2): Building Product Disclosure and Optimization - Sourcing of Raw Materials
- Conformity with LEED v4 MRc 4 (Option 1 and Option 2): Building Product Disclosure and Optimization - Material Ingredients
- Conformity with LEED v4 MRc 2 (Option 1): Building Product Disclosure and Optimization - Environmental product declarations
- IBU Environmental Product Declaration (EPD) available
- Cradle to Cradle Certified™ Silver
APPROVALS / STANDARDS
- CE Marking and Declaration of Performance to EN 13956 - Polymeric sheets for roof waterproofing
Product Declaration
EN 13956: Polymeric sheets for roof waterproofing
Chemical Base
Flexible polyolefins (FPO)
Reinforcing Material
Multi-layer synthetic membrane based on flexible polyolefines (FPO) with an internal reinforcement of glass-fleece, polyester and a polymer non-woven backing of not more than 70 g/m2.
Shelf Life
5 years from date of production.
Storage Conditions
Product must be stored in original unopened and undamaged packaging in dry conditions and temperatures between +5 °C and +30 °C. Store in a horizontal position. Do not stack pallets of the rolls on top of each other, or under pallets of any other materials during transport or storage. Always refer to packaging.
Visible Defects
| Pass | (EN 1850-2) |
Length
| 10,00 m (-0 % / +5 %) | (EN 1848-2) |
Width
| 2,00 m (-0,5 % / +1 %) | (EN 1848-2) |
Effective Thickness
| 2,4 mm (-5 % / +10 %) | (EN 1849-2) |
Straightness
| ≤ 30 mm | (EN 1848-2) |
Flatness
| ≤ 10 mm | (EN 1848-2) |
Mass per unit area
| 2,60 kg/m² (-5 % / +10 %) | (EN 1849-2) |
System Structure
The following products must be considered for use depending on roof design:
- Sarnafil® AT-18 FSA P self adhered membrane for parapet
- Sarnafil® AT D Sheet for detailing
- Sarnafil® T Metal Sheet
- Sarnabar® / Sarnafast® /Sarnaweld®
- Sarnafil® T Welding Cord
- Sarnacol® T 660
- Sarnafil® T Clean
Compatibility
The substrate can be one of the following materials:
- Concrete, lightweight concrete, screed, brick masonry, plaster, Oriented Strand Boards (OSB), plywood panels, timber boards, metal decking.
- All thermal insulation types and levelling layers suitable for roofing. No additional separation layer is required.
- Existing bituminous roofing that is clean and level e.g. re-roofing over old flat roofs. Discolouration of the membrane surface may occur if in direct contact with bitumen.
Resistance to Impact
| hard substrate | ≥ 4000 mm |
| soft substrate | ≥ 4000 mm |
Hail Resistance
| rigid substrate | ≥ 34 m/s |
| flexible substrate | ≥ 46 m/s |
Resistance to Static Load
| soft substrate | ≥ 20 kg |
| rigid substrate | ≥ 20 kg |
Resistance to Root Penetration
| Pass | (EN 13948) |
Tensile Strength
| longitudinal (md)1) | ≥ 950 N/50 mm |
| transversal (cmd)2) | ≥ 900 N/50 mm |
1) md = machine direction
2) cmd = cross machine direction
Elongation
| longitudinal (md)1) | ≥ 18 % |
| transversal (cmd)2) | ≥ 18 % |
1) md = machine direction
2) cmd = cross machine direction
Tear Strength
| longitudinal (md)1) | ≥ 300 N |
| transversal (cmd)2) | ≥ 300 N |
1) md = machine direction
2) cmd = cross machine direction
Joint Peel Resistance
| failure mode: C, no failure of the joint | (EN 12316-2) |
Joint Shear Resistance
| ≥ 400 N/50 mm | (EN 12317-2) |
Dimensional Stability
| longitudinal (md)1) | ≤ |0,4| % |
| transversal (cmd)2) | ≤ |0,2| % |
1) md = machine direction
2) cmd = cross machine direction
Foldability at Low Temperature
| ≤ -50 °C | (EN 495-5) |
Water Tightness
| Pass | (EN 1928) |
Exposure to Bitumen
| Pass | (EN 1548) |
3) Sarnafil® AT is compatible to old bitumen
Effect of Liquid Chemicals, Including Water
| Resistant to many chemicals. Contact Sika Technical Services for additional information. | (EN 1847) |
UV Exposure
| Pass (> 5000 h / grade 0) | (EN 1297) |
External Fire Performance
| BROOF (t4) < 20° (subject to system) | (EN 13501-5) |
Reaction to Fire
| Class E | (EN ISO 11925-2, classification to EN 13501-1) |
Application
Ambient Air Temperature
-20 °C min. / +60 °C max.
Substrate Temperature
-30 °C min. / +60 °C max.
EQUIPMENT
Hot welding overlap seams
Electric hot air welding equipment, such as hand held manual hot air welding equipment and pressure rollers or automatic hot air welding machines with controlled hot air temperature capability of a minimum +600 °C.
Recommended type of equipment:
- Manual: Leister Triac
- Automatic : Sarnamatic 681
- Semi-automatic: Leister Triac Drive
SUBSTRATE QUALITY
The substrate surface must be uniform, smooth and free of any sharp protrusions or burrs, etc. Sarnafil® AT-25 must be separated from any incompatible substrates / materials by an effective separation layer to prevent accelerated ageing. The supporting layer must be compatible to the membrane, solvent resistant, clean, dry and free of grease and dust. Metal sheets must be degreased with Sarna Cleaner before adhesive is applied.
APPLICATION
Installation procedure
Strictly follow installation procedures as defined in method statements, application manuals and working instructions which must always be adjusted to the actual site conditions.
Fixing method- General
The waterproofing membrane is installed by loose laying ( without stretching membrane or installing under tension) with mechanical fastening in seam overlaps or independent from overlaps. Overlap seams are hot air welded using specialised hot air equipment.
Fixing method-Linear fastening (Sarnabar®)
Unroll the Sarnafil® AT-25 membrane, overlap by 80 mm, weld immediately and fix to the substructure by means of the Sarnabar® fasteners. The preferred type of fastening will be advised by Sika. The spacing of the fasteners is in accordance with the project specific Sika calculations. The perimeter piece ends must be secured with the Sarnabar® Load Distribution Plate. For protection fasten a piece of Sarnafil® AT-25 under bar end and plate. Leave a 10 mm clearance between bar ends. Do not fasten in hole nearest bar end. Cover the bar ends with a piece of Sarnafil® AT-25 and weld. After installation the Sarnabar® must immediately be made watertight with a Sarnafil® AT-25 cover strip. At upstands and at all penetrations, the Sarnafil® AT-25 membrane must be secured with a Sarnabar®. The 4 mm diameter S-Welding Cord protects the Sarnafil® AT-25 roof covering against tearing and peeling off by wind uplift.
Fixing method-Spot fastening (Sarnafast®)
Sarnafil® AT-25 must always be installed at right angles to the deck direction. Sarnafil® AT-25 is fixed by means of the Sarnafast® fasteners and barbed washers/tubes along the marked line, 35 mm from the edge of the membrane. Sarnafil® AT-25 is overlapped by 120 mm. The spacing of the fasteners is in accordance with the project specific Sika calculations. At upstands and at all penetrations, the Sarnafil® AT-25 membrane must be secured with a Sarnabar®. The 4 mm diameter S-Welding Cord protects the Sarnafil® AT-25 roof covering against tearing and peeling off by wind uplift.
Fixing method - Field fastening
Sarnafil® AT-25 is fixed by induction welding Sarnadisc hot melt coated washers and Sarnafast® fasteners according to the project specific instructions. Sarnafil® AT-25 is overlapped by 80 mm. The spacing of the fasteners is in accordance with the project specific Sika calculations. At upstands and at all penetrations, the Sarnafil® AT-25 membrane must be secured with a Sarnabar®. The 4 mm diameter S-Welding Cord protects the Sarnafil® AT-25 roof covering against tearing and peeling off by wind uplift.
Fixing method-Loose laid
The roof waterproofing membrane is installed by loose laying and covered with the appropriate roof material according to the roof design and the local wind loading conditions. Mechanical fixing along the roof perimeter with Sarnabar® including T-Welding Cord must be used to keep membrane in place.
Fully bonded roof junctions and flashings
The membrane is bonded to the substrate and flashing by using Sarnacol® T 660 contact adhesive. Refer to Product Data Sheet.
Self adhered roof junctions / flashings / upstands
The membrane is bonded onto the adjointing surfaces using Sarnafil® AT FSA P self adhered membrane. Refer to Product Data Sheet.
Hot air welding method
Overlap seams must be welded by electric hot air welding equipment. Welding parameters including temperature, machine speed, air flow, pressure and machine settings must be evaluated, adapted and checked on site according to the type of equipment and the climatic conditions prior to welding. The effective width of welded overlaps for all methods by hot air must be minimum 80 mm.
Testing overlap seams
The seams must be mechanically tested with screwdriver (rounded edges) to ensure the integrity/completion of the weld. Any imperfections must be rectified by hot air welding.