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JohnPeters Posted: Oct 11, 2008 08:05 PM	Building code and R-value I would think that most of us here got into the plural component polyurethane insulation business for one reason - we believe it is the best / most cost effective way to create an energy efficient home. I have learned to deal with filter glass and cellulost's position in the market place as nothing other than seniority. Both products have been around for a long time and as a result they typically get a first glance. But what gets my goat is how building code is designed around their features. When is that going to change? I am up against R-38 roof decks / attic spaces and I cannot figure out why I am installing inches upon inches of foam up here. Its over kill! When is code going to create separate insulation R-value requirements for air permeable insulation and non-permeable? We could postion ourselves much more competitively if there was a level playing field here. R-38 of SPF and R-38 of filter glass are two different things. They are not comparable given ASTM testing standrds for filterglass and its inability to work effectively in a real world environment. SPF should not have to be 3 to 4 times more expensive then filterglass. Thoughts Mason? Is anyone lobbying to change this?
mason Posted: Oct 11, 2008 09:40 PM	I have spent most of my adult life on this issue. Lots of research has been conducted the last 10 years that is beginning to get traction in the design community and spilling over into the building code arena. ASTM 1363, is one of the test procedures that may be used to determine R value of materials. It can be modified to test with air pressure diffentials as well as just conduction. ICC Evaluation Services is aware of testing conducted by SPFA and the American Plastics Council that demonstrates SPF performs 30 to 40% more efficiently when tested with this procedure using air pressure differentials. Many are working to have ICC ES accept the modified procedures as a way for suppliers to qualify their products as a performance equivalent to building code prescribed "R values using thickness of SPF that compares to the equivalent R value of fiberglass. So, if a fiberglass rated at R 38 performed at 67% efficiency at 10 degrees F with a simulated 15 mph wind pressure and a SPF rated at 21 performed at 100% efficiency, the SPF would be a performance equal and thereby accepted. It hasn't been accepted yet, but, it should be coming. Keep your fingers crossed and support the research that can help bring these changes.
Gerry Wagoner Posted: Oct 15, 2008 09:42 PM	Perhaps the switch to "U value" in the United Kingdom three years ago may provide a pattern for America.
Posted: Oct 15, 2008 10:30 PM	The question is always asked. Why only R-30 or R-38 with foam, why not fill the cavity. People think I am just giving a sales pitch. That is all the care about "R" value. I lost a job to another contractor who was to install 4" at R-28(30) INITIAL R-value where I was going to install 5" at R-30 (water blown initial and aged). His bid was $400 less than me, I refused to meet it. Yeah that's it, pay more for less, good thinking Mr. Happy Homeowner. Tim
mason Posted: Oct 16, 2008 07:55 AM	When you use SPF (either open or closed cell), filling the stud cavity does not provide greater energy performance, moisture or air infiltration control. Plus, filling the stud requires additional trimming and waste of foam. After a certain thickness of foam (depends on the climate and building's use and environment), no appreciable energy performance is gained with increase thickness of foam. For every inch extra of foam you install, the costs go up 2 to 3 times compared to fiberglass. So why install 5 inches when 4 inches works just the same?
Posted: Oct 16, 2008 06:49 PM	I was referring to the roof where minimum code is R-30. I would agree that 4-5" is splitting hairs. However, if my bid was for 5" and competitor was for 4" and were basically the same price, then the customer is paying more for less. Also, selling a product based on initial R-value I believe to be dishonest. The customer does not get what in the end what he pays for up front. I would spray 4" if the code officer would allow R-24 in the roof, but they do not, so I am required to spray 5" Tim
mason Posted: Oct 17, 2008 07:19 AM	R values do have some meaning. The aged R value of a closed cell foam with HFC 245 fa blowing agent blend (aged 180 days) can range between 5.8 to 6.6 per inch depending on the formula. The manufacturer is required to provide the aged R value on the product data sheet. If the intitial R value is R 7, the aged R value would be around R 6 to 6.2. (note: 90% of the R value reduction takes place in the first 180 days, so any residual R value reduction is minimal.) A closed cell water blown foam will average between 4.5 to 5.1 per inch typically. As you suggest the aged R value of a water blown foam does not change over time. So presume your waterblown foam has the higher R value of 5 and the competitive foam has a 6. Four inches of their foam would yield an aged R value of 24 and 5 inches of your waterblown foam would yield a R value of 25. Both products will perform equally as an air barrier, reduce the potential for condensation and water intrusion, and enhance structural performance. So, in this case, yes 4 inches of their stuff equals 5 inches of your stuff. .
Posted: Oct 17, 2008 01:11 PM	Well I won't argue with you, but will try and offer some clarification. The supplier of my water blown foam's technical data sheet indicates an aged R-Value of 6 per inch. So I am basing this experience on my competitors foam with an initial R-Value of 7 and my foam with a specified aged R-Value of 6. I am not comparing the performance of the foam as I agree there is little difference between 4-5". If the competitor is charging by R-value and is in fact installing less foam they are getting more money for less material. Tim
mason Posted: Oct 17, 2008 05:57 PM	While I am skeptical of a water blown foam with an R value of 6. If it is legitimate it would be equal to a typical HFC 245 fa blend. However, I have been involved in testing foam for a long time. I have never seen a water blown system with R values that high. The reason the non water blowing agents are higher is that they are poorer conductors of heat than the water blown foams. I don't know how they can change physics. CFCs. HCFCs, HFCs all are going to produce foams with higher R values than water blown foams.

Author

Comments

JohnPeters

Posted: Oct 11, 2008 08:05 PM

Building code and R-value

I would think that most of us here got into the plural component polyurethane insulation business for one reason - we believe it is the best / most cost effective way to create an energy efficient home.

I have learned to deal with filter glass and cellulost's position in the market place as nothing other than seniority. Both products have been around for a long time and as a result they typically get a first glance. But what gets my goat is how building code is designed around their features.

When is that going to change? I am up against R-38 roof decks / attic spaces and I cannot figure out why I am installing inches upon inches of foam up here. Its over kill!

When is code going to create separate insulation R-value requirements for air permeable insulation and non-permeable?

We could postion ourselves much more competitively if there was a level playing field here. R-38 of SPF and R-38 of filter glass are two different things. They are not comparable given ASTM testing standrds for filterglass and its inability to work effectively in a real world environment.

SPF should not have to be 3 to 4 times more expensive then filterglass.

Thoughts Mason? Is anyone lobbying to change this?

mason

Posted: Oct 11, 2008 09:40 PM

I have spent most of my adult life on this issue. Lots of research has been conducted the last 10 years that is beginning to get traction in the design community and spilling over into the building code arena.

ASTM 1363, is one of the test procedures that may be used to determine R value of materials. It can be modified to test with air pressure diffentials as well as just conduction. ICC Evaluation Services is aware of testing conducted by SPFA and the American Plastics Council that demonstrates SPF performs 30 to 40% more efficiently when tested with this procedure using air pressure differentials.

Many are working to have ICC ES accept the modified procedures as a way for suppliers to qualify their products as a performance equivalent to building code prescribed "R values using thickness of SPF that compares to the equivalent R value of fiberglass.

So, if a fiberglass rated at R 38 performed at 67% efficiency at 10 degrees F with a simulated 15 mph wind pressure and a SPF rated at 21 performed at 100% efficiency, the SPF would be a performance equal and thereby accepted.

It hasn't been accepted yet, but, it should be coming.

Keep your fingers crossed and support the research that can help bring these changes.

Gerry Wagoner

Posted: Oct 15, 2008 09:42 PM

Perhaps the switch to "U value" in the United Kingdom three years ago may provide a pattern for America.

Posted: Oct 15, 2008 10:30 PM

The question is always asked. Why only R-30 or R-38 with foam, why not fill the cavity. People think I am just giving a sales pitch. That is all the care about "R" value. I lost a job to another contractor who was to install 4" at R-28(30) INITIAL R-value where I was going to install 5" at R-30 (water blown initial and aged). His bid was $400 less than me, I refused to meet it. Yeah that's it, pay more for less, good thinking Mr. Happy Homeowner.

Tim

mason

Posted: Oct 16, 2008 07:55 AM

When you use SPF (either open or closed cell), filling the stud cavity does not provide greater energy performance, moisture or air infiltration control. Plus, filling the stud requires additional trimming and waste of foam. After a certain thickness of foam (depends on the climate and building's use and environment), no appreciable energy performance is gained with increase thickness of foam.

For every inch extra of foam you install, the costs go up 2 to 3 times compared to fiberglass.

So why install 5 inches when 4 inches works just the same?

Posted: Oct 16, 2008 06:49 PM

I was referring to the roof where minimum code is R-30. I would agree that 4-5" is splitting hairs. However, if my bid was for 5" and competitor was for 4" and were basically the same price, then the customer is paying more for less. Also, selling a product based on initial R-value I believe to be dishonest. The customer does not get what in the end what he pays for up front. I would spray 4" if the code officer would allow R-24 in the roof, but they do not, so I am required to spray 5"

Tim

mason

Posted: Oct 17, 2008 07:19 AM

R values do have some meaning. The aged R value of a closed cell foam with HFC 245 fa blowing agent blend (aged 180 days) can range between 5.8 to 6.6 per inch depending on the formula. The manufacturer is required to provide the aged R value on the product data sheet. If the intitial R value is R 7, the aged R value would be around R 6 to 6.2. (note: 90% of the R value reduction takes place in the first 180 days, so any residual R value reduction is minimal.)

A closed cell water blown foam will average between 4.5 to 5.1 per inch typically. As you suggest the aged R value of a water blown foam does not change over time.

So presume your waterblown foam has the higher R value of 5 and the competitive foam has a 6. Four inches of their foam would yield an aged R value of 24 and 5 inches of your waterblown foam would yield a R value of 25.

Both products will perform equally as an air barrier, reduce the potential for condensation and water intrusion, and enhance structural performance.

So, in this case, yes 4 inches of their stuff equals 5 inches of your stuff.
.

Posted: Oct 17, 2008 01:11 PM

Well I won't argue with you, but will try and offer some clarification. The supplier of my water blown foam's technical data sheet indicates an aged R-Value of 6 per inch. So I am basing this experience on my competitors foam with an initial R-Value of 7 and my foam with a specified aged R-Value of 6. I am not comparing the performance of the foam as I agree there is little difference between 4-5". If the competitor is charging by R-value and is in fact installing less foam they are getting more money for less material.

Tim

mason

Posted: Oct 17, 2008 05:57 PM

While I am skeptical of a water blown foam with an R value of 6. If it is legitimate it would be equal to a typical HFC 245 fa blend.

However, I have been involved in testing foam for a long time. I have never seen a water blown system with R values that high. The reason the non water blowing agents are higher is that they are poorer conductors of heat than the water blown foams. I don't know how they can change physics. CFCs. HCFCs, HFCs all are going to produce foams with higher R values than water blown foams.

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