𝐒𝐮𝐧𝐝𝐚𝐲'𝐬 𝐓𝐇𝐎𝐔𝐆𝐇𝐓𝐅𝐔𝐋 𝐏𝐨𝐬𝐭 : 𝐏𝐏𝐔-𝐁𝐚𝐬𝐞𝐝 𝐑𝐨𝐨𝐟𝐢𝐧𝐠 𝐒𝐲𝐬𝐭𝐞𝐦

 𝐒𝐮𝐧𝐝𝐚𝐲'𝐬 𝐓𝐇𝐎𝐔𝐆𝐇𝐓𝐅𝐔𝐋 𝐏𝐨𝐬𝐭:

🏗 𝐏𝐏𝐔-𝐁𝐚𝐬𝐞𝐝 𝐑𝐨𝐨𝐟𝐢𝐧𝐠 𝐒𝐲𝐬𝐭𝐞𝐦: 𝐓𝐞𝐜𝐡𝐧𝐨𝐥𝐨𝐠𝐢𝐜𝐚𝐥 𝐈𝐧𝐧𝐨𝐯𝐚𝐭𝐢𝐨𝐧 𝐨𝐫 𝐚 𝐑𝐢𝐬𝐤𝐲 𝐄𝐱𝐩𝐞𝐫𝐢𝐦𝐞𝐧𝐭?

This question has been on my mind, and I want to bring it up for professional discussion with my colleagues. I recently encountered a telling example of this type of roofing system being implemented in Central Asia, and the consequences were disastrous.

Let's take a closer look at a case where a client chose the following roofing system structure:

1️⃣ Substrate: Profiled steel sheeting and vapor barrier.

2️⃣ Thermal Insulation: Rigid PPU (polyurethane foam) with a density of 60 kg/m³, thickness of 100 mm.

3️⃣ Waterproofing: Hybrid polyurea, 2 mm.

4️⃣ Finish: One-component polyurethane coating for UV protection.

Unfortunately, the reasons for choosing this particular "pie" remain unknown, but the results of its service life forced us to investigate the causes of the rapid deterioration of the layers.

What did we discover during the inspection?

🔍 Uneven PPU Layer: The insulation layer was applied with height variations of up to 2 cm. This led to the formation of stagnant zones and uneven load distribution.

🔍 Craters in the Coating: Numerous defects appeared due to ignoring dew point control and gross violations of the spraying technology.

🔍 Delamination at Joints: Adhesion failure occurred at overlap areas. The reason is simple — a lack of dust removal and degreasing between layers. The overlap areas were not prepared (not sanded/scuffed).

🔍 Topcoat Failure: The one-component polyurethane paint delaminated literally within one season. Presumably, it was applied to a contaminated (dusty) polyurea surface, causing the coating to peel off easily.

Key Conclusions:

✅ This roofing system design requires truly meticulous work from the contractor. This is not a case where minor shortcomings can be overlooked.

✅ The success of the system critically depends not only on the contractor's qualifications but also on the quality of the materials themselves (the brands of which, by the way, were not disclosed to us).

✅ Strict adherence to climatic parameters, surface preparation, interlayer drying times, and the technological application process is not just a recommendation but the only condition for durability.

✅ Important Note: For regions with extreme UV exposure, a much more reliable finishing solution would be the use of two-component polyurethane topcoats. They offer greater chemical resistance and durability under direct sunlight.

Would I recommend this system to my clients?

More likely NO than YES. The risks associated with human error and material quality are still too high. And in harsh climates, mistakes are forgiven much less often.

What is your experience with sprayed roofing systems? Have you encountered similar problems in hot climates? Let's discuss in the comments! 👇

source : Andrey Andreev

#roofing #construction #PPU #polyurea #sprayfoam