Quick Insulation Tips
R-value does not take into consideration heat loss due to air movement. Both open cell and closed cell insulation materials are “air barriers”. Comparing an air porous insulation to and air barrier material by looking at the R-value just doesn’t work. Below are a few things to keep in mind.
Just because we are in Ottawa, Ontario it doesn’t mean you need more R-value
R-20 of spray foam stops about 95 percent of heat loss
R-49 of spray foam stops about 97 percent of heat loss. Therefore, you have paid a lot of extra money for only a small amount of increased performance (look at attached chart). Where is the payback in that?
Spray foam will stop warm air from penetrating the insulation and condensing on the cold roof/wall sheathing regardless if its open cell or closed cell.
If you stop the air flow you should not need to apply a vapor barrier in Maine regardless of open cell or closed cell. In fact, not having a vapor barrier will help if there is a leak because the roof will be able to dry quicker. For fiberglass, roxul, or cellulose it may make a good idea because all of those products allow warm air to pass through and condense on the sheathing.
All fiber products will allow condensation to occur. Always keep in mind if you see condensation you know that you are loosing heat. Heat loss by air movement is what causes condensation. Always. Condensation does not occur from a product being vapor open or vapor closed. It is simply coincidence that air permeable insulation like fiberglass, roxul, and cellulose are also vapor open. Open Cell Spray foam is an air barrier but is also vapor open.
Open Cell Foam will allow water to penetrate and drain through it in a roofdeck. Once the water source is fixed the material will dry and retain its R-value.
Open Cell Spray Foam does not act like a sponge. It has been installed in millions of homes all over the world in cold climates with zero documented issues. If someone tells your that ask for documentation. Remember, no insulation should ever be used to stop water from entering a house. Regardless of what insulation you use other than Blue Board, if the insulation is submerged in water it will be come saturated over time. If your walls are submerged in water you have a much bigger problem than what insulation was used. This sounds silly but we hear all the time “won’t open cell spray foam let water into it?”. The answer is yes of course. However, once your leak is fixed the material will dry with no adverse affects. The added benefit being if you see a leak in your roof, you will no exactly where it is. With closed cell spray foam it can be very hard to find a leak because it traps the water. This I actually have seen in real life. I have witnessed open cell get wet and dry as well.
Be careful what you read online. Unfortunately most of the information on the internet is pushed by some sort of an agenda. Make sure claims are backed up with actual real world testing of houses that have been in service for a number of years and then inspected. Below I am going to attach a few documents of tests just like that.
Economic Thickness of Thermal Insulation
This document shows you how once your wall or roof reaches R-20 of a spray foam insulation 95% of the heat loss is stopped. Why put in more!? R-49 of closed cell spray foam will never pay itself back. It costs about twice as much as our open cell R-20 system but performs exactly the same. We make less money but that doesn’t concern us because we know we will get the next job from you!Download
Quick Points on Economic Thickness
Shows how putting in 5 inches of an Open Cell Spray Foam will stop 95 percent of heat-loss
Most contractors will try to get you to put in atleast R-38 of a spray foam. This is very expensive and does not pay you back.
R-20 of Open Cell is about 5 inches of material. This is more than enough to cover everything efficiently.
Open Cell does not contain any gas like closed cell does. Closed cell will off-gas over time and lose some of its R-value.
Open Cell will not lose its R-value or off-gas.
If closed cell gets wet the R-value will be cut in half.
Quick Points on Economic Thickness
- Shows how putting in 5 inches of an Open Cell Spray Foam will stop 95 percent of heat-loss
- Most contractors will try to get you to put in at least R-38 of a spray foam. This is very expensive and does not pay you back.
- R-20 of Open Cell is about 5 inches of material. This is more than enough to cover everything efficiently.
- Open Cell does not contain any gas like closed cell does. Closed cell will off-gas over time and lose some of its R-value.
- Open Cell will not lose its R-value or off-gas.
- If closed cell gets wet the R-value will be cut in half.
For those that are not very tech savvy I can give your the quick points – Vancouver
- All buildings checked has Icynene Open Cell installed a number of years previous
- Some buildings had vapor barriers and some did not.
- Some buildings had good ventilation and some did not.
- Every building had a small section of insulation ripped out and the exterior sheathing was tested for moisture content.
- RESULTS! Every single building tested showed that the exterior sheathing did not have a high moisture level.
- We recommend using Icynene Open Cell Spray Foam
- The number one reason is that it is water blown. This means that there are no harmful blowing agents in the material.
- The only gas that exists within the material is air. Therefore, there is no off gassing with this product. It also means that there is no gas within it that can break down the insulation over time. That was a problem about 10 years ago when people were digging into houses sprayed with closed cell which used a poor blowing agent. The foam had broken down over time. This supposed to not be happening any more.
- Icynene Open Cell has 30 years of documented use in northern climates. Some of the closed cells we are spraying now are only 6 months old. They have been constantly reformulating closed cell spray foams over the past 30 years to make them healthier and more affordable. So how do we know those products will still be performing well 20 years from now. With Icynene Open Cell we know because of its history.
- Icynene Open Cell is vapor open. This will allow any moisture that does get in will always be able to get out. One common issue we have seen over the years is below windows or doors that were not flashed correctly. Water was able to get in. When closed cell foam was used we found rotting because that moisture was not allowed to get out.
- With all open cells or closed cells if not installed properly there can be issues. However, if installed correctly those issues don’t exist. With open cell sometimes there can be some pull away from the studs if the material is too hot. This is fixed very easily by going around the whole building and just touching up with the gun in those areas. You don’t see this happen much with closed cell. However, if the wall is damp the closed cell will not adhere at all. The point is if a product is not installed correctly then you may see pull away but it really is not something that should be factored into your decision on what product to use. Just make sure those areas are touched up.
- Open cell absorbs about 80 percent of reflective sound. Closed Cell absorbs about 30 percent.
- The payback with our open cell performance system is 1-2 years over fiberglass compared to around 10 years with a closed cell R-49 system.
We hope this was helpful. Its obviously in favor of Open Cell spray foam but sometimes there is a right way and a wrong way. Especially when looking at the dollars.