ONE Generally speaking, what is your take on applications being performed in cold weather? Specifically, how well do Canadian contractors handle cold installation conditions and how well suited are SPF products for being applied in cold conditions?
Dave Andre, Morrison Hershfield: In our experience, the applications performed in cold weather are working in Canada. However, new contractors/installers need to be aware of the differences between warm and cold spraying, and the various techniques used for successful applications. Cold-weather formulas react differently than the regular or warm-weather formulas. The onus is on the installer to be familiar with the different weather formulations and associated temperature limitations. When the manufacturer’s parameters are followed, we rarely see any issues. If the parameters are not followed, prepare for a “gong show.” There are also some varying conditions based on interior or exterior application. Exterior applications have challenges related to wind and snow.
Brad Glazier, IFTI: It’s that time of year again: the temperature starts to drop and you need to start ordering cold weather formulations. We all go through it, and after a couple of weeks of cursing the clogging tip, we remember last winter’s spray settings and get back in the grove. At least we have the option now of spraying in the winter; not so long ago there was no “C” formulation and essentially business stopped when it got too cold out. With the correct formulation and attention by the installer, cold weather spraying is just another day at the office for the Canadian SPF contractor.
Marc Kast, Elastochem: The real issue is the transition from spraying in warm weather to cold weather. Most applicators forget to keep the materials warm overnight, as it is still warm during the day so they allow the materials to get below 18 degrees C (64 degrees F). As the temperatures begin to drop during the daytime hours, they are more diligent in ensuring the raw chemicals are kept warm.
Adam Luffman, Urethane Foam Consultants: Application of spray foam in cold conditions requires contractors to keep a closer watch on the storage conditions of their chemicals, as well as monitor the suitability of substrate and ambient temperature throughout the application process. The risk of not taking care in the upcoming season is potentially foam that has poor adhesion characteristics and is at a higher risk of going off-ratio during installation. Contractors can minimize these risks by making sure their rigs are adequately prepared and they are working with their chemical supplier to ensure they have the most up-to-date information regarding spray parameters. Manufacturers can provide the best guidance on when to switch from summer to winter systems, and what equipment settings are optimal for each material.
Brian Pedersen, SWD Urethanes: In general, most experienced contractors have learned through trials and experience how to transition fairly well into colder temperature applications. The challenge for most applicators is looking through that crystal ball trying to predict the Canadian weather in their region to determine when to order winter formulations and then when to make the switch. The next challenge is to make the required adjustments not only on the equipment and processing side, but how they actually spray. Most cold weather formulations will react quite well if manufacturers’ recommendations are followed. For manufacturers, it can be a production and inventory challenge just simply due to the vastness of the Canadian geography and weather. Some places in the country may be ready for cold temperature formulations three to four weeks earlier than others. Some areas may never have to transition due to their location.
Scott Ruffett, Icynene: In a country where much of the population is in a heating season for four or five months of the year, we need to adapt and look for solutions to ensure we can continue spraying when the temperature drops below zero. Most Canadian contractors are trained or have experience in cold-weather applications and can handle most of these conditions fairly easily. Unfortunately, the last few years have been extremely cold, causing many contractors to lose a considerable amount of production days.
Cold temperatures will affect some projects more than others. Exterior applications of medium-density foams need to be managed differently than interior applications of light-density foams, as weather, precipitation, wind speed, and ambient air temperature need to be considered before sending the crews out. Foam contractors quoting work that might be done during the winter months must point out to their customers that there may be a need for heating and/or hoarding, and that comes with a cost. Determining who is paying for what at the quote stage ensures the project runs smoothly as possible.
Compared to other insulation and air/vapour barrier products, select SPF products have an advantage and are well suited for cold weather applications. Many of the competing products as well as adhesives used for board stock insulation materials have cold temperature limitations. Water-blown light-density foams can be sprayed down to approximately negative 25 degrees C, while water-blown medium density foams have more flexibility than chemically blown medium-density foams in cold temperatures.
TWO What are some common pitfalls of cold weather applications, and the considerations needed to avoid them?
Dave Andre: The usual suspects for construction in cold climates are frosty/wet substrates. Most things don’t stick well to this type of surface, including SPF. We also see applications that are too thick and develop thermal cracking. Typically, the foam should be installed in two-inch passes. Also, some provisions need to be made for controlling ambient and/or surface temperatures depending on the severity of the cold. By monitoring thickness and following recommended cold weather techniques, you can often prevent thermal cracking. Lastly, challenging surfaces for SPF such as concrete and steel are only made worse by the cold. Having sufficient lead-time for surface preparation and subsequent weather protection prior to application is critical.
Brad Glazier: The obvious issue is always getting used to spraying the winter formulation again. However, the biggest issues I used to see were to do with temperature, not necessarily ambient, but of the chemicals and the equipment. Hose insulation has taken a beating all summer when it’s not as critical, so take the time before the weather changes to inspect your hoses and replace your insulation. Every time the applicator stops spraying, his hose will change temperature. It’s not so noticeable in the summer, but come winter, this can lead to a “chase your tail” scenario of constantly playing with temperatures. The other mistake is not heating the chemicals. A lot of applicators think that because the proportioner is heating the chemical that the barrel temp doesn’t matter. Even if the Delta “T” of your machine is capable of dealing with the cold chemical, you are causing yourself grief by not warming the barrels–remember the change in viscosity. A cold drum will have a huge impact on your pressures and mix ability, so when your tip is gumming up and the foam is not behaving properly, don’t just call your sales rep and tell them their foam sucks; warm your barrel up and get back to easy spraying. Oh, and it’s also easy to forget to close the door on your rig; a warm barrel doesn’t stay that way with the back door open.
Marc Kast: Choose the system wisely if you plan on spraying on steel or concrete, as adhesion is an issue with some foams. Flash passes (less than one-quarter inch) are not recommended, as the density of the flash pass will be much higher than the subsequent passes and as the foam cools there will be a tendency for the foam to either split, crack, or delaminate. Heating the area with a propane or electric heater prior to the application of the foam is another concern, as the substrate will develop a high level of moisture. If heating is to be utilized it should be initiated at least 72 hours prior to spraying or not at all.
Adam Luffman: Two common pitfalls of cold weather application would include improper storage of chemical components and application of foam in environmental conditions that are outside of parameters set out by the manufacturer.
If spray foam is applied to a substrate that is below the manufacturer’s specified parameters, there can be issues with adhesion, cracking, and poor yield as a result of a bad reaction. To minimize these concerns, contractors should ensure they are utilizing temperature-controlled storage for chemicals and have properly functioning and suitably-sized heating systems on the spray-rigs. This ensures little time is wasted on the job site getting material to temperature, and also helps ensure the chemical components are not comprised from poor storage.
On-site evaluation and testing of installed foam is the only way for the installers to be certain that the foam is in compliance with national standards. Contractors should ensure each spray rig is outfitted with a complete field test kit, and installers understand the importance of adhesion and density tests. Having an accurate idea of density and an assurance of proper adhesion helps contractors maximize yield and minimize call-backs over cracking or poorly adhered foam.
Brian Pedersen: I think the biggest challenge is just simply remembering how and what it feels like to spray the colder temperature formulations, and then make the adjustment. Secondly, sprayers really need to focus on the substrate temperatures, not just the ambient. Substrate temperatures can be quite a bit lower than ambient in many instances. If they are only checking ambient and it falls within the range, but the substrate temperature is below the range, it’s going to be a long, tough day. Lastly, applicators really need to get and keep those drums warm. Material drums should be stored someplace warm overnight and then heated prior to application.
Scott Ruffett: Site conditions change rapidly during the winter: temperatures rise and drop; unpredictable winds and lake effect snow can bring unwanted conditions quickly. For exterior applications, sunny days can be difficult, especially in the afternoon. Big swings in temperatures can make spraying difficult as substrates can be warmed by the sun, or kept cold by the thermal mass effect caused by an extremely cold night. Knowing the site conditions (i.e. where is the shade and sun; is the site protected from cold winds; etc.) and the current weather forecast for the day can make for a successful project during the winter. For interior applications or hoarded exterior applications, construction heaters can be used to raise the ambient temperatures to acceptable levels. Caution must be used, as you do not want to use a heater, which introduces moisture into the air.
THREE How could installation processes and/or products be improved for cold weather applications, if at all?
Dave Andre: The industry needs to do a better job of educating installers about cold weather product limitations and manufacturer formulations. Good communication with general contractors is also important, as weather limitations often have direct impacts on construction schedules. Although the general contractor is often focused on schedule, the project-specific teams still have expectations regarding quality and rely on certified installers. In that regard, we have seen challenging site conflicts between schedule and weather limitations turned around with good communication from installers and technical support by manufacturer’s representatives.
Brad Glazier: Warm your chemical, warm the jobsite, and make sure the insulation on your hose is good so you can maintain a temperature and enjoy the fact that you’re in a Tyvek suit and not sweating for once. Cold weather spraying can be even better than summer spraying as long as you pay attention to the equipment, use the right system, and do everything you can to warm the job site up prior to spraying, especially if spraying concrete. And make sure the job site is prepped so once you pull the trigger, you can spray steady until break time. This will lessen the temperature swings if you don’t have good insulation, or even when you do, not allow as much drop in temperature from all that hose lying in the snow.
Marc Kast: The key to successful application in cold or extreme cold weather is system selection and product storage. Ensuring the products are warm before they are placed on the rigs is critical, as is keeping them warm throughout the day. Some manufacturers foam work better than others when the temperatures are below freezing. Consult your manufacturer’s Product Data Sheets before selecting a product. If the chemical representative tells you it’s ok to spray below the recommended parameters, be wary, as the manufacturer will not warranty any failures and a quick search on the Internet will confirm the ambient temperature for the day the foam was applied.
Adam Luffman: It is up to each contractor to assess site conditions and make a determination of whether it is suitable to spray or not. Tight deadlines and the schedules of other trades can often pressure the installation of foam. Contractors need to be aware of the risks of spraying outside of the parameters set out by each chemical manufacturer. It is prudent at this time of year that contractors document environmental and material conditions on daily work records, as required by the national installation standard. This practice helps provide an assurance that the contractor followed the standard, should any issues arise in the future. Proper training and manufacturer field support help contractors make these determinations.
Brian Pedersen: Heated workspaces and warm chemicals are your friends in colder temperatures. It always amazes me that some applicators refuse to invest in drum heaters and heating their rigs overnight. Spraying cold chemicals on cold substrates results in processing issues, a frustrated sprayer, lost production, and reduced yield. I understand the pressure of schedules and getting the job done, however we as an industry need to educate our customers, builders, and general contractors on the temperature parameters in which we can be successful. I believe a delayed application due to weather and temperatures that is done right is much better than a bad application done on time. The result is coming back, ripping out, remediating, and losing money. •