Phenolic Insulation Board for Cavity Walls

Author Message Stephen Wilson
Intermediate Member
Username: swilson

Post Number: 4
Registered: 02-
Posted on Wednesday, February 03, - 08:25 am:    Hi all,

Has anyone out there had any experience using Phenolic Insulation Boards? I recently came across an ad for the product, which has an R-value of R-8 per inch, and can be used in cavity walls like any other insulation board. (Can also be used in NFPA 285 assemblies.)

As far as I can tell, Kingspan is the only company that markets it, under the trade name Kooltherm K8. Does anyone out there have experience using it on projects? With thermal preformance so much higher than your typical XPS or Polyiso, I'm wondering "what's the catch?" (Cost I'm sure, but I also wonder how it performs on-site in installation.) James Sandoz, AIA, CSI, CCS
Senior Member
Username: jsandoz

Post Number: 313
Registered: 06-
Posted on Wednesday, February 03, - 08:47 am:    Stephen, type "phenolic insulation and corrosion" into a search engine and see what comes up. I remember several years back hearing that roofs with phenolic insulation and metal decks experienced corrosion of the deck when the roof leaked and the insulation got wet. Dave Metzger
Senior Member
Username: davemetzger

Post Number: 789
Registered: 07-
Posted on Wednesday, February 03, - 10:03 am:    I see no mention in the manufacturer's product data about aged U-value. I'd be leery about basing insulation thickness on the published values alone. Michael Chusid, RA FCSI CCS
Senior Member
Username: michael_chusid

Post Number: 579
Registered: 10-


Posted on Wednesday, February 03, - 02:28 pm:    Phenolic insulation was introduced in the s by Koppers. Fantastic thermal performance. It was pulled from the market however due to long-term problems with performance. I don't recall the specifics. Perhaps Kingspan has solved the problems.

BTW, I was part of a consulting team advising Koppers. They asked me to write guide specs for the product using different styles of specifying: Proprietary, Performance, Descriptive, etc. It was a wonderful exercise that improved my skills as a specifier. Koppers got insight, too, into how to position and promote the product. Michael Chusid, RA FCSI CCS 1-818-219-
www.chusid.com www.buildingproduct.guru Paul Sweet (Unregistered Guest)
Unregistered guest
Posted on Wednesday, February 03, - 01:22 pm:    If I remember correctly the higher R value was right. As James Sandoz said it does attack metal when it gets wet. I would only consider it for locations that won't get wet. Cavities get wet, so it would probably corrode the brick ties or other veneer fasteners. ken hercenberg
Senior Member
Username: khercenberg

Post Number:
Registered: 12-


Posted on Wednesday, February 03, - 03:08 pm:    Wow. Koppers. I remember when they still had some great roofing systems.

As I recall the phenolic insulation corrosion issue first became a problem in Canada where it was much more widely used. Seems to me that the failures north of the border precluded its usage catching on in the US.

As many forensics articles have noted over the years, everything leaks given enough time. Perhaps using non-metallic ties and anchors is advisable when using this insulation since even vapor drive and condensation could possibly set it off if it's still an issue. John Bunzick
Senior Member
Username: bunzick

Post Number:
Registered: 03-
Posted on Tuesday, February 16, - 10:52 am:    I do remember problems with phenolic insulation when I was doing roof consulting work. I got curious, and found that phenolic seems to be currently available for piping insulation. For other applications, Kingspan reportedly has a formulation that reduces the acidity that caused the corrosion. Here's an interesting article. Paul Sweet (Unregistered Guest)
Unregistered guest
Posted on Tuesday, February 16, - 04:40 pm:    Thanks for the article reference. It might be OK for hot water pipe insulation, but I'd want to see some long-term testing results before thinking of using it for chilled water pipe insulation. I've seen chilled water piping in humid locations eaten away because the foam rubber insulation wasn't properly sealed, and water vapor got to the pipes, condensed, and was trapped by the insulation, so it rusted the pipes from the outside. Stephen Wilson
Advanced Member
Username: swilson

Post Number: 5
Registered: 02-
Posted on Wednesday, February 17, - 10:54 am:    Thanks, all! Considering the previous generation of phenolic insulation boards was last used when I was in elementary school, no wonder I hadn't heard of the history.

It will be interesting to see how Kingspan's product performs over time. I noticed roof applications is conspicuously absent from their list of applications, so it sounds like they are trying to avoid that kind of liability again. The brick tie corrosion issue is a good question though. Ed Storer
Senior Member
Username: ed_storer

Post Number: 94
Registered: 05-
Posted on Sunday, June 06, - 08:06 pm:    I worked in Atlanta when One Atlantic Center (aka IBM Building) was constructed in the 's.

From Wiki: "One Atlantic Center was designed by Johnson/Burgee Architects. As associate architect, Heery International, Inc. produced the contract documents."

Koppers phenolic insulation was used in the granite-clad walls. I'm pretty sure that none of the fasteners for the stone anchorage penetrated the insulation.

I've never heard of any problems with the exterior of the building, so I guess it's not a problem after 30 years. Ed Storer, CSI Member Emeritus Curt Norton, CSI, CCS
Senior Member
Username: curtn

Post Number: 253
Registered: 06-


Posted on Wednesday, October 06, - 09:46 am:    I would suggest talking directly to Kingspan about this. I met with their rep and brought up the same issue. They stated that the chemistry is different now. I can't imagine a company would spend the money on NFPA 285 testing for endless assemblies if the chemistry would still corrode fasteners. (Unregistered Guest)
Unregistered guest
Posted on Friday, October 29, - 02:58 pm:    Good Afternoon Everyone,

Thank you for your interest in Kooltherm (Phenolic) insulation. I would be more than happy to answer your questions on the NFPA 285 testing completed and the old Phenolic from the /'s that had corrosive problems. If you would like to discuss these topics, please me at .

Andrew Wilson
Kooltherm (Phenolic) Product Manager
Kingspan Insulation LLC

Phenolic foam is a very versatile material suitable for a large range of applications where thermal performance, moisture resistance, fire performance and in certain cases structural strength are key performance criteria. Phenolic foam is the only material that can provide this unique range of benefits and is used in a variety of applications:

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Heating, Ventilating and Air Conditioning (HVAC)
The foam is cut to accurate tolerances on computer controlled cutting equipment. Parts available include traditional half sections, slotted slab, foil faced phenolic foam laminate ductboard, radius and bevelled lags, bends, flange box covers, valve box covers, etc. Materials are generally supplied with a vapour barrier facing. High density foam is also available for structural applications such as pipe and duct supports.

Building and Construction
Phenolic foam is used in many building applications, typically continuously laminated phenolic board is used in roofing, cavity board, external wall board, plasterboard dry lining systems, wall insulation, floor insulation and as a sarking board. The superior fire performance of phenolic foam is being recognised and this is leading to increased market share in these areas.

Factory Engineered Composite Panels
Composite panels comprise of a high density structural phenolic foam core with steel facings both sides and an appropriate jointing system. These panels are used in a range of applications including food processing factories, cold stores, semi conductor clean rooms and hospitals. These panels are structurally sound and fit for purpose for use in walk-on ceilings. The excellent fire performance provided by the phenolic foam core gives both good insulation and integrity performance in the 3m furnace fire resistance test.

If you are looking for more details, kindly visit Langfang Clear Chemical.

Process / Petrochemical
Phenolic foam is used in process/petrochemical applications for the insulation of pipework, tanks, vessels etc.

Specialist Applications
Phenolic foam is also used in a number of highly specialised applications including fire doors, highly fire resistant panels and for insulation in surface ships, off-shore installations and submarines.

For more information, please visit Phenolic Pipe Insulation.