Retrofit: Basement Foundation Wall Insulation Choices

Basement block foundation wall insulation

I have been auditing & retrofitting homes as an additional service to my remodeling company for 3 years now. My all-star insulator sadly passed away recently and I am just getting started with a new provider.

This new provider has specified Polypropylene Scrim Kraft to insulate unfinished basement block walls:
http://www.jm.com/insulation/building_insulation/products/bic447_ba...  

Thus far, I have used Thermax on my projects: 2" foil faced poly-iso taped at ALL seams. He indicated that the PSK (Polypropylene Scrim Kraft) is cheaper, also satisfies the code for fire, and has a white finish which looks better. The JM product is formaldehyde free.

The 2 products have very close thermal values and I suspect will perform similarly when taped at seams and installed continuously.

My concern is moisture and durability. We know that moisture moves through block walls. This home does not have active bulk water infiltration issues, but I am still hesitant to use a fiberglass product against a masonry wall.

 

What do you use? How do you install it?

I look forward to your input.

Thanks in advance.

Views: 1937

Reply to This

Replies to This Discussion

I am going to be upfront and say this is one application of our insulating coating that I have not performed myself.

 

Our distributor in Texas has painted / coated basements and foundation walls for many years.  All of his referrals are by word of mouth and he has never bothered to gather data, statements or pictures, at least none that he can find on his computer.  If you go to our site, at the top is his name and Cell number, Joe Merrell.

 

Give Joe a call and he can tell you all about the jobs, results, cost, etc.  He has had excellent results spraying the block walls, A/C and heatibg ducts and under the floors of houses.

 

Oh yeah, we are rated at 4.93 US Perms and are a Class A Type 1 Fire Retardant

 

http://www.ct-texas.com

 

 

I have no experience with Polypropylene Scrim Kraft.  However, we all know that Thermax does a great job and that wet fiberglass is a huge problem.  I can't see how fiberglass on a basement wall would be anything other than a huge headache.  I surely wouldn't switch without a multiple house third party study that showed Polypropylene Scrim Kraft effective.

I am really suspicious when I read on their site that Polypropylene Scrim Kraft Non-Perforated (according to site, resists water vapor transmission) is recommended for most basement walls.  We have known for years that nothing should be put on basement walls (that are below grade) that resists water vapor transmission.  Below grade walls can only dry to the inside. Any vapor barrier would trap moisture inside the walls leading to possible mold and rot problems.

Until our local building code converted to 2009 IEEC this stuff was used by a number of builders in this area.  I bought a house with it draped on the basement walls.  Removed draped insulation package and installed 2" foam to concrete, sealed seams and framed and rocked interior so we could use basement.  The draped material did not fully cover wall, had gaps, tape seams were open,  and in no way did a reasonable job of insulating the basement walls.  It was just the cheapest way to meet the code - again proving a house built to code is the worst possible house you can buy!

Applied to concrete basement walls with rollers and brushes.  Cerama-Tech's perm rating is 4.93 US Perms.  Never had a moistrue problem reported and has solved many mold problems.

 

http://www.ct-texas.com

I would like to offer my two cents and say it is always preferable to insulate on the outside so the foundation stays warm instead of the inside where the foundation is cold and runs the risk of condensation if air by-passes the interior insulation.  It is often difficult to insulate on the inside unless the basement is tottaly clear of items.

RSS

Forum Discussions

How would you insulate this roof?

Started by David Butler in General Forum. Last reply by David Butler 11 hours ago. 15 Replies

Psychrometric Chart Training

Started by John Krochmalny in Training. Last reply by Mahendra Shah 14 hours ago. 1 Reply

Dirty solar panels

Started by Evan Mills in General Forum. Last reply by Stacie Bagnasco on Monday. 1 Reply

Latest Activity

tedkidd replied to Bob Blanchette's discussion Tankless Water Heaters... has their time finally come?
"Yeah. Gas water…"
3 hours ago
Eric Kjelshus replied to Bob Blanchette's discussion Tankless Water Heaters... has their time finally come?
"With super cheap natural gas prices now, still worth going all electric?  Tankless needs a lot…"
4 hours ago
Stuart Langley liked Chris Clay's photo
9 hours ago
David Butler replied to David Butler's discussion How would you insulate this roof?
"Stuart, I wasn't considering the copula windows... yes, those would indeed need to be…"
11 hours ago
Stuart Langley replied to David Butler's discussion How would you insulate this roof?
"Well, @David Butler, you have seen the property more accurately than I have, but my impression of…"
11 hours ago
David Butler replied to David Butler's discussion How would you insulate this roof?
"@ Stuart,I don't think there's any concern about impact of 4" build-up on elevation…"
12 hours ago
Stuart Langley replied to David Butler's discussion How would you insulate this roof?
"So this building has a few issues with air leaks and air leaks have so much to do with discomfort…"
12 hours ago
Stuart Langley replied to David Butler's discussion How would you insulate this roof?
"John Hatfield has the right idea here for a new roof deck. Polyiso boards always need a good stout…"
12 hours ago

Photos

  • Add Photos
  • View All

© 2017   Created by Home Performance Coalition (HPC)   Powered by

Badges  |  Report an Issue  |  Terms of Service