Is Polyurethane Waterproof? Types and Application
Yes, polyurethane (PU) is a waterproof material. It consists of a polymer that is made up of chains of organic units joined by carbamate links. This carbamate line composition creates a closed-cell structure that completely blocks water, making it an excellent material for waterproofing. Due to water waterproof capability of polyurethane, it can be used as a waterproofing membrane for buildings and constructions.
Polyurethane is mainly available in 5 types such as water based oil based, thermoplastic, thermosetting, and polyurethane foam. All of these PU types are highly water resistant. But its waterproofing capability depends on the material it is applied on.
As waterproofing experts, Aqviz, we use polyurethane on concrete, wood, and metal to waterproof the surface. So far, we have got amazing results with the PU. In order to have proper result prom PU you should follow the correct method statements and proper maintenance as well as layer protection. We highly recommend you use PU as a waterproofing membrane.
Is Water Based Polyurethane Waterproof?
Yes, water based polyurethane is waterproof due to its strong water-resistant properties when it is applied on the surface. It creates a protective barrier that prevents water from seeping into surfaces making it a reliable choice for waterproofing applications. Polyurethane waterproofing is not entirely impervious to prolonged water exposure it significantly reduces water absorption and protects surfaces from water damage.
Water based polyurethane can be used for wood floors, furniture, kitchen cabinets, concrete surfaces, and even outdoor decks to protect from the water and sunlight. The lifespan of water-based polyurethane typically ranges from 3 to 7 years. However, it depends on the level of wear, exposure to moisture, and maintenance.
Read More: 6 Types of Polyurethane: Best for Waterproofing Projects
Is Oil-Based Polyurethane Waterproof?
Yes, oil based polyurethane is waterproof due to its dense, hard wearing finish and superior moisture resistance. It forms a thick, durable protective layer that effectively repels water. Hence it is highly effective in waterproofing applications. And also oil based polyurethane provides better water resistance than water based polyurethane.
You can use oil-based polyurethane on hardwood floors, wooden furniture, outdoor decks, doors, and marine applications where a tough, waterproof finish is required. The lifespan of oil based polyurethane ranges from 5 to 10 years, depending on exposure to moisture, sunlight, and wear conditions.
Is Thermoplastic Polyurethane (TPU) Waterproof?
Yes, thermoplastic polyurethane (TPU) is waterproof due to its high density molecular structure and excellent water resistance. TPU forms a seamless, flexible barrier that repels moisture. Unlike traditional polyurethane, TPU offers superior long term water resistance, even under extreme environmental conditions.
TPU is widely used in roofing membranes, waterproof clothing, footwear, inflatable boats, phone cases, and protective coatings for electronics and automotive parts. TPU lifespan ranges from 7 to 15 years. But it depends on environmental exposure, mechanical wear, and maintenance.
Is Thermosetting Polyurethane Waterproof?
Yes, thermosetting polyurethane is waterproof due to its high density cross linked structure. Thermosetting polyurethane does not soften under heat and is stable even in extreme environmental conditions.
Thermosetting polyurethane is commonly used for industrial waterproof coatings, rigid foam insulation, marine applications, pipelines, protective coatings for metal and concrete, and waterproof adhesives. The lifespan of thermosetting polyurethane ranges from 10 to 20 years.
Is Polyurethane Foam Waterproof?
No, polyurethane foam is not completely waterproof, but it is highly water resistant. While closed cell polyurethane foam has a dense structure that repels water effectively, open-cell polyurethane foam is more porous and can absorb moisture over time.
Polyurethane foam is used for roof insulation, waterproofing basements, sealing gaps in walls, flotation devices, and marine applications. We have seen that polyurethane foams withstand 10 to 25 years with proper maintenance and protection.
Does Polyurethane Waterproof Concrete?
Yes, polyurethane waterproofs concrete by forming a seamless, moisture resistant barrier that prevents water penetration. Both polyurethane coatings and polyurethane sealants effectively protect concrete surfaces. Water-based polyurethane provides a breathable, clear finish, while oil-based and thermosetting polyurethane offers a more durable, chemical-resistant, and waterproof layer. Polyurethane membranes are also commonly used for high performance waterproofing in heavy duty applications.
Polyurethane is most compatible with poured concrete, precast concrete, concrete slabs, driveways, foundations, and walls. It enhances the durability of garage floors, patios, basements, bridges, and industrial flooring, preventing cracking, spalling, and moisture damage overtime. Polyurethane’s strong adhesion, flexibility, chemical resistance, UV resistance, breathability, and thermal insulation help protect concrete from temperature fluctuations, heavy traffic, and weathering.
This Concrete Waterproofing guide helps to seal the concrete for DIYs and professionals
Does Polyurethane Waterproof Wood?
Yes, polyurethane waterproofs wood by creating a protective, water resistant barrier that prevents moisture penetration. Both oil based and water based polyurethane effectively waterproof wood. Oil based polyurethane offers greater durability and deeper penetration, while water-based polyurethane provides a clearer finish with faster drying times.
Polyurethane is most compatible with hardwood, softwood, engineered wood and plywood waterproofing. It enhances the durability of oak, maple, pine, cedar, teak, and mahogany, making them more resistant to water damage, warping, and rotting. Polyurethane’s flexibility, adhesion, chemical resistance, thermal insulation, breathability, and UV resistance help protect wood from environmental factors like heat, humidity, and sunlight exposure. Normally, polyurethane can last 5 to 15 years on wood surfaces.
Does Polyurethane Waterproof Metal?
Yes, polyurethane waterproofs metal by forming a durable, moisture-resistant protective coating that prevents water penetration and corrosion. Both oil based and water based polyurethane can be used for the metals. Oil based polyurethane provides superior durability and chemical resistance, while water based polyurethane offers a clear, flexible finish with faster drying time.
Polyurethane is most compatible with steel, aluminum, iron, copper, and galvanized metals. It is widely used for metal roofing, bridges, pipelines, machinery, marine vessels, and outdoor metal structures, protecting against rust, oxidation, and weathering. Polyurethane’s strong adhesion, flexibility, chemical resistance, UV resistance, breathability, and thermal insulation help metal surfaces withstand extreme environmental conditions.
