Foam insulation can be applied via either spraying or injecting procedures, depending primarily on the specifications of the project. To put it simply, insulating an open nook or a new construction via spray foam provides optimal results, whereas injection is better suited for sealing enclosures in retrofitting projects. It is important to remember that the two insulation techniques rely on distinct mechanics, in accordance to the conditions of the application and the substance utilized.
One might consider that point and shoot foam guns simplify the task considerably compared to fiberglass batt installation, but in actuality, the entire process is more complex and challenging. Let’s find out what you need to remember.
A critical component in terms of achieving an optimal insulation consists of learning the distinction between the two types of applicators. In spite of the fact that contractors mainly employ spraying foams, the injection-based applicators still play a major role within the industry.
Both spraying and injection mechanics are similar in terms of expansion, however the rate at which they expand differs considerably. In essence, while sprayed foam requires a few seconds to settle, its injected counterpart takes several minutes. Controlling and slowing down the rate of expansion for injected insulation foam via catalysts is critical for preventing excessive pressure inside the enclosure and disastrous results.
Dual component foams, for both sprayed and injected insulators, have to be formulated correctly prior to the application. Otherwise, the consequences incurred vary between highly toxic emissions and a low quality insulations. Numerous factors influence the ratio of the mixture, and specialized measurement equipment is necessary to ensure on-site quality control readouts. Monitoring the temperature of the mixture and displaying/printing values can also help maintain the compound levels within the correct thresholds.
The lift, which constitutes the elevation of the insulator layer from the surface achieved in a single pass, is different based on the product utilized. With most sprayed insulators, the maximum recommended lift does not exceed 2 inches, but certain products permit layers of up to 6 inches in thickness.
When using closed-cell foams, excessive thickness applications could translate into decomposition and/or chemical ignition. Open-cell foam is more permissive in terms of chemical reaction generated heat, but don’t forget that the rate of expansion is over 3 times higher. That can lead to the development of large cavities with a negative impact on the R-value of the materials.
In most cases, managing the lift requires only paying attention to the sequencing and being patient, but in others situations the lift simply cannot be controlled properly. Therefore, electing to use an injection applicator to insulate the tougher sections first is recommended.
The substrate’s temperature is often critical when insulating a surface during the cold season, because the heat it absorbs has a realistic chance of negatively influencing the foam’s ability to bond and expand correctly. The same goes when the installation is performed at high temperatures. In addition, don’t forget that certain substrates – such as polyethylene sheets – are inherently problematic since they tend to break the bonds. Excessive moisture contents might also prevent the insulation foam from adhering properly.
When you’re spraying multiple layers of insulation foam on a surface, you have to be patient and treat each lift as an individual substrate. Permit the sprayed foam to cool before a subsequent application. The waiting time is also critical when subsequently using injected insulation foam, as contractors should allow the former to expand before inserting a new one. It may feel that you’re slowing down the construction project, but in reality you’re ensuring that the insulation is properly installed and effective.
There is a specific type of insulation foam for every venture, and learning how to determine the optimal variety is something that comes with experience. The chemical clock, which essentially represents the rate at which the foam expands and adheres to the surface, determines the effectiveness of the insulator. For example, slowly rising foams should be employed in projects that require decreasing the pressure within a certain cavity, whereas a sprayed-on foam is a better choice when the job implies filling open frame voids.
Selecting a quality insulation foam, applying the correct one in accordance to project specs and allowing it to expand/cool according to the manufacturer recommendations are all mandatory steps in ensuring optimal results. However, you can’t guarantee that the job is well down without implementing a set of protocols for verifying the quality of the mixtures on-site and making sure that all the contractors respect them to the letter.