SikaSeal®-173 - Bituminous mastic for roofs, gutters and downpipes
SikaSeal®-173: bituminous mastic for repairing roofs, gutters and downpipes
SikaSeal®-173 is a roofing sealant and adhesive based on bitumen reinforced with cellulose fibres. Those fibres are what give it body: the bead does not sag on slopes and fills holes and cracks without running, something a bituminous mastic without fibre cannot do.
It is designed for classic roof maintenance: bonding and sealing asphalt membranes, patching rainwater gutters, sealing chimney flashings, finishing downpipes and closing holes and cracks in roofs and wall surfaces. It offers very good resistance to weathering and UV rays, so it holds up when left exposed without additional protection.
✅ Main advantages
Reinforced with cellulose fibres: does not sag on slopes and fills gaps and cracks.
Compatible with asphalt membrane: bitumen on bitumen, the natural bond on a roof.
Very good UV and weather resistance: designed to be left exposed.
Adhesion to metal and wood: gutters, downpipes, sheet metal and board decking.
Ready to use: one-component, in a cartridge, no mixing or heating.
🏗️ Recommended applications
Sealing and bonding roofing membranes and asphalt felt overlaps.
Repair of rainwater gutters.
Sealing of flashings and chimney junctions.
Finishing and joints of downpipes.
Filling holes and cracks in roofs and exterior walls.
📋 Technical specifications
Chemical base: bitumen reinforced with cellulose fibres
Colour: black
Density: 1.3 kg/l · ISO 1183-1
Application temperature: the substrate must be at least 3 °C above the dew point
Service temperature: -20 °C to +70 °C
Substrates: bitumen, metal and wood
Resistance: very good to weathering and UV rays
Packaging: 300 ml cartridge
Shelf life: 12 months from the date of manufacture
🧰 Directions for use
Remove standing water, leaves and loose dirt from the area to be repaired.
Brush off rust and flakes of old, poorly bonded bitumen until you have a firm substrate.
Check the dew point: the substrate temperature must be at least 3 °C above it to avoid condensation under the bead.
Cut the nozzle to the size of the crack or overlap and fit the cartridge into the gun.
Extrude the material, pressing it into the crack or overlap until it is completely filled.
Spread and press with a spatula to ensure contact across the whole surface.
Clean tools and splashes while fresh; once hardened, it can only be removed mechanically.
🛡️ Standards and certificates
Product from the SikaSeal® range by Sika España with published Product Data Sheet and Safety Data Sheet
The product data sheet does not declare an EN 15651 classification for this reference
📦 Supply formats
300 ml cartridge · black
💡 Professional tip: bitumen and silicone do not get along. If the same roof has a joint sealed with SikaSeal®-171 or any silicone, do not overlap one product over the other: they do not bond to each other and the repair will open up at the first heat cycle. And do not apply it on a cold, damp roof at dawn: if the substrate is not 3 °C above the dew point, there is a film of condensation that prevents adhesion even though it looks dry.
Technical data according to the SikaSeal®-173 Product Data Sheet from Sika España (version 01.01, March 2023).
Frequently asked questions
What is SikaSeal®-173 used for?
It is a bituminous mastic for roof maintenance: bonding and sealing asphalt membranes, repairing gutters, sealing chimney flashings, finishing downpipes and closing holes and cracks in roofs and exterior wall surfaces.
Does it withstand weather and sun?
Yes, the description indicates very good resistance to weathering and UV rays, so it can be left exposed. Its service temperature ranges from -20 °C to +70 °C and it is black.
What substrates can it be applied to?
On bitumen, metal and wood. Before applying, remove water, leaves and dirt, brush off rust and check that the substrate is at least 3 °C above the dew point. Do not overlap it onto joints sealed with silicone.
What format does it come in and how long does it keep?
It comes in a black 300 ml cartridge, ready to use with a gun, with no mixing or heating. It keeps for 12 months from the date of manufacture.
Frequently asked questions about Sika products (mortars, adhesives and sealants)
How do I know which size and quantity to buy?
Each product page includes the approximate yield or consumption (for example kg/m² or metres of bead per cartridge) in the "Technical specifications" section. Calculate the surface area or thickness of your project and multiply by that consumption to find out how many units you need. If in doubt, contact us with the measurements of your job.
Where can I find the complete technical data sheet (Product Data Sheet)?
The description of each product already includes the main technical data (strengths, setting times, application temperature, applicable standards, etc.), taken from the official Sika Spain Product Data Sheet. If you need the complete PDF data sheet or the safety data sheet (SDS), write to us and we will send it to you.
Do these products comply with European regulations (CE marking)?
Most Sika products carry the CE marking in accordance with the relevant European standard (for example EN 1504 for structural repair, EN 12004 for tile adhesives, EN 13888 for grouts or EN 15651 for sealants). The exact standard for each reference is detailed in the "Standards and certificates" section of its product page.
What protective equipment do I need to apply them?
It depends on the product: cement-based mortars and adhesives are usually irritating to skin and eyes (gloves, goggles and a mask are recommended), while polyurethane sealants and adhesives require good ventilation. Always check the safety section of the product page and its safety data sheet (SDS) before use.
How should I store these products and how long do they last unopened?
Shelf life and storage conditions (temperature, humidity, protection from light) vary depending on the type of product (cementitious, polyurethane, epoxy, etc.) and are stated on the packaging and in the data sheet of each reference. In general, it is advisable to store in a dry place, protected from frost and direct sunlight.
Can I return a Sika product if I haven't used it?
Yes, you have 14 calendar days from receipt to exercise your right of withdrawal, provided the product is in its original packaging and has not been opened. The cost of return shipping is borne by the customer. Contact us at info@vetonek.com or via WhatsApp on +34 629 571 735.
How long does my order take to arrive?
We ship to mainland Spain, the Balearic Islands, Portugal and the other European countries we serve (France, Belgium, the Netherlands, Germany, Italy, etc.). The estimated delivery time is 3 to 9 working days (no shipping to the Canary Islands, Ceuta or Melilla).
Todo excelente. Tras una primera equivocación con el producto elegido, el equipo de atención al cliente se puedo a trabajar para solucionar el problema y darme una solución adecuada.
