What is an elastomer?
An elastomer is a polymer with pronounced resilient properties that can stretch by tens to hundreds of percent under load and then returns fully to its original shape. Thanks to their unique combination of elasticity, watertightness and durability, elastomers are widely used in construction for seals, dampers, bearings and sealants.
What makes elastomers special?
Elastomers consist of long polymer chains that are lightly cross-linked. As a result:
- they can stretch dramatically without breaking (often 200–700%)
- they spring back fully after release
- they are water- and airtight
- they keep their properties between −40 °C and +120 °C
- they have a low elastic modulus (E ≈ 0.01–0.1 GPa)
Commonly used elastomers in construction
| Type | Abbreviation | Known for |
|---|---|---|
| EPDM rubber | EPDM | Roofing membranes, façade foils |
| Neoprene | CR | Vibration isolators, bearings |
| Polyurethane | PU | Adhesives, joint sealants, floors |
| Polysulfide | PS | Glazing sealant, underwater joints |
| Silicone | SI | Sanitary sealant, glass joints |
| Butyl rubber | IIR | Vapour barrier tapes, sealing tapes |
Application in construction
Elastomers are essential for:
- Roofs — EPDM membrane as a waterproof layer
- Bridge bearings — accommodating expansion, contraction and rotation
- Glazing joints — sealant between frame and glass
- Sanitary spaces — sealing joints in kitchens and bathrooms
- Vibration isolators — under machines, fans and pumps
- Façades — air-sealing transitions
- Floors — polyurethane coatings and poured floors
Pros and cons
Pros
– great stretch and recovery
– durable when correctly specified
– watertight and sound-absorbing
– low maintenance
Cons
– UV-sensitive (some types)
– not bonding to all substrates
– difficult to recycle
– higher initial cost in some systems
Related terms
- Elasticity
- EPDM
- Sealant
- Polyurethane
- Sliding bearing
- Plastic
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