How to Insulate Rim Joists with DuPont Froth-Pak Spray Foam (Flash & Batt Method)

Sealing rim joists is a crucial step in improving a home's energy efficiency and preventing drafts.
One of the most effective ways to do this is by using the Flash and Batt method, which combines spray foam and batt insulation to provide superior air sealing and thermal resistance. In this video, we’ll show you how to use DuPont’s Froth-Pak Spray Foam to insulate rim joists and sill plates as an efficient and cost-effective method.
DuPont’s Froth-Pak Spray Foam Insulation is a portable, professional-grade system that delivers fast, high-performance results for residential and commercial remodeling projects. It’s efficient, easy to use, and ideal for contractors looking to save time and improve insulation quality.
There are three effective insulation methods for rim joists and sill plates:
1. Full Cavity Spray Foam - Provides an airtight seal and superior insulation. Spray foam completely fills the cavity, sealing cracks and gaps while offering a high R-value.
2. Flash and Batt - A hybrid method that involves applying a thin layer of spray foam (the "flash") to seal the cavity, followed by batt insulation. This approach offers both air sealing and thermal resistance.
3. Rigid Foam and Batt - Combines rigid foam insulation with batt insulation to provide a solid air barrier and excellent thermal resistance, making it a cost-effective yet efficient option.
This video will focus on using the Flash and Batt approach with DuPont’s Froth-Pak 210 Spray Foam Insulation to insulate rim joists and sill plates.
Flash and Batt with DuPont’s Froth-Pak
The DuPont Froth-Pak is a perfect solution for the Flash and Batt insulation method. This technique combines the benefits of both spray foam and fiberglass batt insulation to seal rim joists and enhance energy efficiency. It’s a simple, two-step process that is highly cost-effective and reduces air leaks.
2-Step Method:
1. Apply Froth-Pak Spray Foam: A thin layer (around ¼") seals cracks, gaps, and air leaks in the rim joist, providing a vapor barrier and preventing potential mold or rot. If you apply a thicker layer (around 2”), you can achieve an added R-value of up to 12.2.
2. Install Fiberglass Batt Insulation: After the foam cures, install fiberglass batt insulation to fill the cavity, further boosting the overall R-value for enhanced thermal resistance.
3 Benefits of Using Froth-Pak:
1. Cost-Effective: The Flash and Batt method uses less spray foam, with batt insulation filling most of the cavity. To put it into perspective, a spray foam company typically charges at least $2,400 for the minimum spray area, whereas the cost of a Froth-Pak, PPE, and a roll of insulation can be $600 or less-making it much more affordable.
2. Air Sealing: Froth-Pak effectively prevents drafts, which enhances comfort by maintaining consistent indoor temperatures year-round.
3. Energy Efficiency: Increases R-value and reduces energy consumption, leading to lower utility bills and better overall home insulation.
Why I Like the DuPont Froth-Pak Spray Foam
• Eco-Friendly: No ozone-depleting chemicals and very low odor during application.
• Fast Curing: Tack-free in 30 seconds and fully cured in minutes.
• Versatile: Seals gaps in roof junctions, attic penetrations, electrical and plumbing areas, and basement rim joists. It also helps prevent pests from entering.
• Energy Efficiency: Significantly reduces energy costs by sealing air leaks and meeting energy code requirements.
• Moisture & Mold Resistance: Prevents moisture intrusion, reducing the risk of mold and mildew growth.
• Fire Safety: Class-A fire rating for safe use in various environments.
Conclusion
To wrap it up, DuPont’s Froth-Pak Spray Foam Insulation is a game-changer offering a cost-effective and reliable solution for improving energy efficiency and insulation performance.
The Flash and Batt method, using Froth-Pak alongside batt insulation, not only saves time and money but also enhances air sealing and thermal resistance in rim joists and sill plates. It’s easy application, fast curing time, and eco-friendly design make it a smart choice for any remodeling project.
The Froth-Pak kit provides an efficient and affordable option that delivers high-quality results. It's a must-have tool for anyone looking to improve insulation while keeping costs down and ensuring long-term performance.
‪@dupont‬ #frothpak #spray foam
#insulation @froth-pak

[@ciscokid2444]

Great video thank you. I wanted to know why you chose the insulation froth pak instead of the sealer one?

[@tumbleweed1976]

Glad to see this video. I’m very leery of spray chemicals in our home. Regardless of R Value.

[@mwrcrft]

While closed spray foam can be applied successfully when applied with the 2 parts mixed correctly ,weather ( cold weather affects foam mixture product (tanks) needs to be at specified temperatures) and applicators experiance can make it great or a serious air quality situation when the foam does not mix properly and has problems curing. If you ever watch professional foam applicator they will do a spray out to make sure the 2 part ratio is correct for conditions. It is a great product when applied in the parameters on the label, so read the label before application. Being a guy I make the exception and do read labels in things I know little about, so please don't pull my man card.

[@ConcordCarpenter]

@@mwrcrft 100%! There are several steps needing to be followed.

[@odelltownsendjr4895]

Can method 1 be executed as a DIY project using the FROTH-PAK 210 Spray Foam Sealant Insulation Kit. Will the 2" barrier this product recommends be sufficient for deploying method 1? Any tips for DIY project for method 1?.. Great Video!

[@donjay5216]

i have a simlar old house, concrete basement, double 2x4 sill plate, with a rimjoist on top. the sill plate is very drafty and has a bunch of BX cabling stapled to it. is it safe/easiest to just blast foam on top of the bx, or should i try to move it before applying the ccsf? thank you!

[@prototype3a]

What flavor of safety goggles were you wearing? They look interesting. I've had a hard time finding eyepro that actually work properly while also wearing a half mask. Someday, I'll probably just get a full face mask.

[@ConcordCarpenter]

Pyrex- spell? They were left over from our safety eyewear head-2-head testing Check out that video

[@prototype3a]

@@ConcordCarpenter Oh. Maybe Pyramex. I have some glasses from them I rather like. Pyramex Ever-lite SB8623DT and SB8610DT

[@ConcordCarpenter]

@@prototype3a yes that’s it

[@virgil3241]

I get this is good, and have been told this to do this for years now. But all this crap coming down from the UK and spray foam and rot from water leaks but not able to dry. So are we back to the Asbestos thing, where it was a good idea, and then found out its terrible?

[@mattv5281]

Do you worry about foam trapping moisture in the rim joist leading to rot? Old homes are never perfectly watertight on the outside.

[@ConcordCarpenter]

@@mattv5281 I make sure all the proper steps to mitigate external water are taken

[@ConcordCarpenter]

@@mattv5281 also the foam prevents the interior sill (warmer side) from developing frost on freezing days- that moisture can cause mold issues.

[@Alittlewondering]

Is foam spray not becoming an isurance problem in america? As in aus&Nz the insurance companies are looking to not insure foam insulated houses due to potential fire hazzard

[@tracykooken2606]

? just maybe ,,, the insalation corp over there is " manipulaing " the bias of gov officials so they can keep out tthe foam industry ?!!. afer all there IS FIRE RATED foams. some are just crack fillers, doors n window types. but whole house ,,, yes.😊

[@ConcordCarpenter]

@@Alittlewondering no problem here. This foam is Class a fire rated. Most ccsf has a fire rating or a paint covering to make the fire repellent

[@virgil3241]

I have a feeling there is going to be some changes with spray foam, seems either from bad install, or other things. More and more info is now coming out

[@Alittlewondering]

@@virgil3241 in NZ its not as broadly used we mostly use woven glass wools or similar especially in new builds, foam is ussually used in existing for if you are not taking the linings off in renovations,

[@virgil3241]

@@Alittlewondering Its everywhere now in North America. And all from the advice from government energy organizations to. New builds and remodels