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Author	Comments
Trey Gibson Posted: Jul 27, 2007 09:40 PM	Warehouse I am bidding on a big job right now, a 24k sq ft warehouse that will house computer servers. They will keep this between 60 and 70 degrees. How many inches of closed cell should I put on the walls and roof? Thanks in advance
SprayFoamSupply.com Posted: Jul 27, 2007 11:42 PM	What part of the country is the building located in? Geo
Trey Gibson Posted: Jul 28, 2007 07:27 AM	Texas
Posted: Jul 29, 2007 03:33 PM	Foamer 1, What part of Texas pardner, It will make a huge difference from one end of this great state to another. Kenneth
mason Posted: Jul 30, 2007 07:43 AM	The amount of sprayfoam insulation required will vary depending on 3 factors. Total thickness required to stop the potential for moisture condensation. Total Thickness to provide the most cost effective R value Total thickness to provide the minimim amount of R value required by building codes. The 3 factors may have different requirements. For example in Houston, TX 1 inch in the walls and 2 inches in the ceiling will prevent condensation but 2 inches in the walls and 3 inches in the ceiling would be the most cost effective for providing insulation value. However, building codes require R 13 in walls and R 30 in ceilings in climate zones 1 and 2. So, to comply you would require 2 inches in the wall but over 5 inches in the ceiling. But, if you have research demonstrating that the sprayfoam insulaton at lower thickness provides equivalent insulation value to higher R values of the most common insulation (ie fiberglass). The building code official is allowed to review that information and allow less R value if the information and data seems credible. A credible source is research from an ICC accredited lab or ICC accredited engineer using test methods recognized by ICC. For example, testing performed at Oakridge National Labs in their large scale attic simulator demonstrates that at both cold and hot temperatures, blown in fiberglass insulation to the floor of an attic loses approximately 50% of its insulation value due to convective currents where sprayfoam installed to the underside of the roof deck in an attic maintained 70 to 80% of its insulation value. A building code official may (or may not) use this information to allow you to use less foam than the prescribed tables call for. So check your codes for your climate area, and go by the prescriptive tables first. They will always require more insulation than is required to stop condensation and to provide the most cost effective thickness of insulation.

Author

Comments

Trey Gibson

Posted: Jul 27, 2007 09:40 PM

Warehouse

I am bidding on a big job right now, a 24k sq ft warehouse that will house computer servers. They will keep this between 60 and 70 degrees. How many inches of closed cell should I put on the walls and roof?

Thanks in advance

SprayFoamSupply.com

Posted: Jul 27, 2007 11:42 PM

What part of the country is the building located in?

Geo

Trey Gibson

Posted: Jul 28, 2007 07:27 AM

Texas

Posted: Jul 29, 2007 03:33 PM

Foamer 1,

What part of Texas pardner, It will make a huge difference from one end of this great state to another.

Kenneth

mason

Posted: Jul 30, 2007 07:43 AM

The amount of sprayfoam insulation required will vary depending on 3 factors.

Total thickness required to stop the potential for moisture condensation.

Total Thickness to provide the most cost effective R value

Total thickness to provide the minimim amount of R value required by building codes.

The 3 factors may have different requirements. For example in Houston, TX 1 inch in the walls and 2 inches in the ceiling will prevent condensation but 2 inches in the walls and 3 inches in the ceiling would be the most cost effective for providing insulation value.

However, building codes require R 13 in walls and R 30 in ceilings in climate zones 1 and 2. So, to comply you would require 2 inches in the wall but over 5 inches in the ceiling.

But, if you have research demonstrating that the sprayfoam insulaton at lower thickness provides equivalent insulation value to higher R values of the most common insulation (ie fiberglass). The building code official is allowed to review that information and allow less R value if the information and data seems credible. A credible source is research from an ICC accredited lab or ICC accredited engineer using test methods recognized by ICC.

For example, testing performed at Oakridge National Labs in their large scale attic simulator demonstrates that at both cold and hot temperatures, blown in fiberglass insulation to the floor of an attic loses approximately 50% of its insulation value due to convective currents where sprayfoam installed to the underside of the roof deck in an attic maintained 70 to 80% of its insulation value. A building code official may (or may not) use this information to allow you to use less foam than the prescribed tables call for.

So check your codes for your climate area, and go by the prescriptive tables first. They will always require more insulation than is required to stop condensation and to provide the most cost effective thickness of insulation.

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