Which PU Foam Should You Choose? A Guide to PU Foam Types
There are many types of construction foam available on the market. They differ in application method, performance, yield, and key properties. If you’re wondering which foam is right for your job, this guide will help you choose with confidence.
Types of PU Foam
Installation foams can be categorized in several ways. Below, you’ll find the most common classifications to help you decide which foam to buy.
Classification of PU Foams by Application Method: Gun-Applied and Hose-Applied
PU foams are most often divided into gun-applied and hose-applied products. Each type has a formulation tailored to its application method, which affects how the foam behaves during use and what properties it delivers.
These differences influence precision, expansion, pressure, and overall performance—but we’ll come back to that in a moment.
• Foam guns – application with a foam gun ensures precision and control, which is especially important when installing windows and doors.
• Hose-applied foams – slightly less precise than gun-applied foams, but practical for filling gaps, voids, and occasional use.
An innovative alternative combining the best features of both solutions is REVO 360° foam. It features a built-in applicator and can be applied in any can position. This revolutionary product makes it easier to reach even hard-to-access areas.
Low-Pressure and High-Expansion PU Foams
Polyurethane foams are also classified by how much pressure they exert and how strongly they expand.
Low-Pressure PU Foam: Key Characteristics
Low-pressure foams are typically gun-applied products. They are designed not to exert excessive pressure on gaps during expansion, which is particularly important when installing windows and doors. Foam with too much pressure can push against jambs and profiles, potentially causing frames to warp.
Where do low-pressure foams work best?
• Window and door installation
• Work with materials that are sensitive to deformation
High-Expansion Foam: Key Characteristics
High-expansion foams are most often hose-applied products. Without going too deeply into the chemistry, hose application requires a formulation that generates higher expansion and pressure.
High-expansion foam expands more vigorously and creates higher pressure inside the gap. These characteristics are not ideal for installing windows and doors, but they are very useful when filling holes in walls, pipe penetrations, or larger voids.
With high-expansion foams, filling 30–40% of the gap is usually enough, as the foam will continue expanding to fill the space. Remember that proper expansion is also affected by factors such as can shake, storage temperature, and moistening the surface before and after application.
Where do high-expansion foams work best?
• Filling voids, cracks, gaps, and pipe penetrations
• Filling and soundproofing partition walls
Summary: Both high-expansion and low-pressure foams have their place in construction work.
Low-pressure foam is ideal for window and door installation, as well as for filling areas where surrounding elements may be sensitive to deformation.
High-expansion foam works well for filling voids where greater expansion and fill volume are needed.
Foam Expansion Pressure vs Post-Expansion
It is also worth clarifying the difference between expansion pressure and post-expansion, as these terms are often confused or used interchangeably.
Expansion pressure refers to the pressure PU foam exerts on surrounding elements, such as window or door frames, during application and curing. This pressure continues to act as the foam reacts with moisture in the air and hardens.
Post-expansion describes how much the foam increases in volume after application during the curing process.
Gun-applied and low-pressure foams usually have lower post-expansion, which is crucial when installing windows and doors. Hose-applied foams, by contrast, increase their volume more significantly after application, making them useful for filling voids.
Winter Foams and Summer Foams
Some foams are designed to perform not only at standard temperatures, but also in sub-zero conditions. Foams with a wider temperature range are especially useful during transitional seasons—between autumn and winter or spring and summer—when mornings can be very cold but temperatures rise during the day.
Classification of PU Foams by Curing Time
Foam curing time depends on several factors, including humidity, ambient temperature, and the foam formulation itself.
Most foams fully cure within 24 hours. However, products such as Tytan Professional ULTRA FAST 70 can fully cure in just 1.5 hours, allowing you to start cutting the foam after only 20 minutes. If speed matters on the jobsite, this can be the perfect solution.
How to Choose the Right Construction Foam for the Job
Now that you know how construction foams are classified and what the differences mean in practice, choosing the right product becomes much easier.
Start with one simple question: where will I use the PU foam?
PU foam is commonly used for tasks such as:
• Installing windows and doors
• Installing fire doors
• Filling gaps, openings, expansion joints, and hard-to-reach spaces
• A wide range of general construction tasks, from occasional door installation to everyday gap filling
Once you know the task, consider additional factors such as curing time, ambient temperature, application method, and the tools you have available.
The Best Foam for Installing Windows and Doors
When installing windows and doors, low pressure, high yield, and a dense, uniform foam structure are essential. Professional installers typically choose gun-applied foams with formulas designed specifically for window and door installation.
The best foam for installing windows and doors should be:
• Low-pressure, so it does not warp frames during curing
• High-yield, so you can install more windows and doors without frequent interruptions
• Dense and uniform, to effectively insulate the spaces around windows and doors
In this case, Tytan Professional 65 foam is an excellent choice because it meets all of these requirements.
If time is critical and you want to install more windows on the same day, select ULTRA FAST 70 foam. In addition to high yield, it fully cures in just 1.5 hours.
For fire door installation, Tytan Professional B1 foam is the recommended choice.
And if you want to take your installation to an even more professional level, the WINS system is the best option. In addition to foams, it includes complementary products that together create a certified window installation system backed by a 15-year warranty.
Comparison of Tytan Professional Foams for Window and Door Installation
| ULTRA FAST 70 Gun Foam | 65 Gun Foam | 65 Gun Foam Winter | GUN Foam All-Season | WINDOW & DOOR Gun Foam | |
| Yield per can | 70-77 l / 870ml | ≤ 65 l / 750 ml | ≤ 65 l / 750 ml | 45 l / 750 ml | ≤ 65 l / 840 ml |
| Ambient temperature | from +5 °C to +30 °C | from +5 °C to +30 °C | from -20 °C to +30 °C | from -10 °C to +30 °C | from -20 °C to +30 °C |
| Pre-curing time | ≤ 20 min * | ≤ 30 min * | ≤ 30 min * | ≤ 40 min * | ≤ 30 min * |
| Full cure time | po 1,5 h * | 24 h | 24 h * | 24 h * | 24h |
Polyurethane Foam for Gaps, Expansion Joints, and Penetrations
Foam for filling gaps is a must-have for every professional. If you use foam only occasionally and for gap filling, buying a foam gun may not be necessary—especially as it requires cleaning and maintenance to last longer.
When choosing foam for filling gaps, pay attention to:
• Foam expansion: if you need to fill a space thoroughly, choose high-expansion foams. They fill voids effectively and are typically hose-applied.
• Post-expansion: higher post-expansion helps the foam continue expanding after application, so you can use less product while still filling the space effectively.
• Application method: most foams are applied with the valve facing down. If you need to fill spaces near the ceiling or in difficult positions, choose a foam that works in any can position, such as REVO 360°.
Hose-applied filling foams are available for different temperature ranges, curing times, and yield levels. The comparison below will help you select the right product for your application.
Comparison of Tytan Professional Foams for Filling Gaps
| STD All Season PU Foam ERGO | Lexy 60 All Season Straw PU Foam | Lexy 20 All Season Straw PU Foam | 2K Quick Mounting Foam | REVO 360° | |
| Yield per can | ≤45 l / 750 ml | ≤ 60 l* / 750 ml | ≤ 20 l / 300 ml | ≤ 10 l / 400 ml | 45-50 l / 780 ml |
| Ambient temperature | from -10 °C to +30 °C | from -10 °C to +30 °C | from -10 °C to +30 °C | from +10 °C to +25 °C | from +5 °C to +30 °C |
| Pre-curing time | ≤ 40 min * | ≤ 40 min * | ≤ 40 min * | ≤ 15 min * | ≤ 50 min * |
| Full cure time | 24 h * | 24 h | 24 h * | 4 h * | 24 h |
| Application method | Valve Down | Valve Down | Valve Down | Valve Down | Any can position |
| Applicator type | Straw | Straw | Straw | Straw | REVO |
Now you know how to choose the right foam for the job and how different types of PU foams differ from one another. If you’d like to learn more about best practices for applying foam, subscribe to our YouTube channel.