Spray Polyurethane Foam or Polyurea?

1. Two spray systems, two different jobs

Spray polyurethane foam and polyurea are both two-component systems sprayed on site. A machine meters the two liquids, which meet at the spray gun, and the mixture reacts on the surface within seconds. From there the two materials differ, because they are formulated for different jobs.

Spray foam is insulation. The mixture expands into a cellular layer. In closed-cell foam, the usual choice for roofs and cold stores, the gas trapped in the cells slows down the flow of heat. Because the foam bonds to the surface as it rises, it also seals the joints, gaps and fixings it covers. The roof or wall gets one continuous insulation layer, without the joints that boards leave.

Polyurea is a waterproofing membrane. It does not foam. Its blend side is based on amines instead of polyols, and amines react with isocyanate very quickly. The result is a tough, elastic coating, usually a few millimetres thick, that keeps water out and stands up to wear. It is not an insulation material. A layer of polyurea on its own will not keep a building warm or a cold store cold.

So the first question on any job is simple: does the surface need to stop heat, stop water, or both?

2. Where each one fits

Most spray work falls into a few groups:

• Roofs and flat roofs. Spray polyurethane foam goes down as one continuous insulation layer over the whole deck, including around upstands, drains and fixings. On an exposed roof the foam then needs a protective top coat.
• Walls and facades. Spray foam insulates the building envelope. Polyurethane foam is also used for sound insulation.
• Cold stores built on site. When a cold store is built in place instead of from factory panels, its walls and ceilings are insulated with spray foam. Factory panels are a different process, covered in our guide to cold room panel manufacturing.
• Below-grade structures. On foundations and other concrete below ground, the job is usually waterproofing, so polyurea is the system here.
• Industrial tanks. Polyurea is used to coat tanks, because the fast-reacting material holds on vertical shells and curved surfaces.

3. When to use both

On many jobs the answer is both, in layers. On roofs and flat roofs, common practice is spray foam first for insulation, then a top coat to protect it.

The reason is sunlight. Polyurethane foam left bare in the sun degrades: ultraviolet light discolours the surface and slowly breaks it down, and wind and rain then wear it away. An exposed foam roof therefore needs a top coat that resists sunlight and weather. Polyurea is one option. It seals the foam against water and gives an elastic, hard-wearing surface for foot traffic and maintenance. Other roof coatings are also used, and the right choice depends on the roof, the budget and how the roof will be used.

One point to check: aromatic polyurea, the most common type, darkens and loses colour in sunlight. Where the colour of the finished surface matters, an aliphatic top coat is often added over it.

As general practice, the top coat goes on soon after the foam, following the system supplier's guidance, so the foam is not left exposed for long. The same order of foam, then coating, is used on other insulated surfaces that face weather or wear, such as the outside of insulated tanks. When the job is only waterproofing, as on foundations, polyurea is sprayed directly onto the prepared surface, with no foam layer.

4. Equipment, surface, climate and safety

Equipment. Spray systems run on high-pressure or low-pressure machines. Both meter the two components and bring them together at the gun, but they work at different pressures and outputs. That is why a system is formulated for the machine it will run on, and why we ask which machine you use.

Surface preparation. Adhesion decides whether a spray job lasts. In general terms:

• The surface must be clean, dry and sound, with no dust, oil, loose material or standing water.
• Concrete usually needs a primer before polyurea, to seal its pores and help adhesion.
• Metal should be free of rust and grease.
• On old roofs, loose layers come off and wet areas are dried out before any foam goes on.

Climate. Crews in Syria, Iraq, the Gulf and Central Asia work with strong sun, hot summers and, in many places, cold winters. General points apply everywhere:

• Moisture is the biggest risk. Water reacts with isocyanate, so spraying onto a damp surface, or in rain, fog or dew, spoils adhesion and, with foam, the foam quality. Keep the surface temperature above the dew point. A common rule is a margin of at least three degrees Celsius.
• Temperature changes the reaction. A roof in summer sun speeds everything up, and a cold surface in winter slows it down and weakens adhesion. On hot roofs, spraying in the cooler hours of the day is common practice.
• Wind carries overspray away. It wastes material and can mark cars and buildings nearby.
• Store drums closed, in the shade and away from heat and frost. Isocyanate reacts with moisture in the air.

Safety. Isocyanates can sensitise the skin and the airways, and repeated exposure can lead to occupational asthma. Spray crews need respiratory protection, gloves and eye protection, and should follow the safety data sheet of the system they use. In the European Union, since 24 August 2023, industrial and professional users of products containing diisocyanates must complete training on safe use before they work with them. It is a sensible benchmark for crews anywhere.

5. What drives the cost per square metre

Contractors price their work per square metre, while spray systems are bought by weight. On site, the cost per square metre depends mainly on two things, and both are set by your job:

• The thickness applied. A thicker foam layer or a thicker polyurea membrane puts more kilograms onto each square metre. For foam, the insulation target sets the thickness. For polyurea, the specification and the wear the surface will see set it.
• The surface sprayed. A flat, smooth deck takes less material than corrugated sheet, rough concrete or a surface with many details. Vertical walls and tank shells also take more time and care than an open roof.

Site work adds to this. Loss to wind, surface preparation, primers and top coats all belong in a realistic price per square metre.

We quote the system itself, based on your application and your expected monthly quantity. Your price per square metre is then built from the thickness, the surface and the site.

6. What to send for a quote, and how JiTPOL supports you

JiTPOL is a polyurethane system house in Bursa, Türkiye. We formulate our own spray foam and polyurea systems and supply each one as two matched components: the JiTPOL blend as component A and the isocyanate matched to it as component B. We adjust the pair to your equipment and your job. The range also covers polyurethane injection work. We export to Syria, Iraq, the Gulf, Central Asia and Europe. To prepare a quote, send us:

• The job: spray foam insulation, polyurea waterproofing, or both
• Your spray equipment: high-pressure or low-pressure
• The surfaces you spray and the substrate: roofs, walls and facades, cold store walls and ceilings, tank shells or foundations
• Where the work is: indoors, outdoors or below grade
• Your expected monthly quantity
• The destination country
• The spray system you use now, if any

Technical data sheets and safety data sheets are sent on request through the quote form, for the system matched to your job. Packaging is confirmed with each quote. Export orders are normally paid in advance by bank transfer in EUR or USD, and terms are agreed with each quote. For suitable projects, our technical team can visit your site and run trials with you.

Selected sources

• PU Europe, Factsheet 22: Differences between closed-cell and open-cell spray polyurethane (PU) foam (December 2025)
• US EPA Safer Choice (archive): Spray polyurethane foam product types
• Wikipedia: Polyurea
• Wikipedia: Polyurethane (light stability, aromatic and aliphatic isocyanates)
• ISOPA: The EU introduces mandatory training of diisocyanates workers from 24 August 2023