Helpful? 0

Covering exposed rigid foam insulation on foundation

I am building a new house and plan to have 4 inches of ridged foam on the outside from the foundation to the eaves. My question is how to cover the portion that is above grade level, but below the siding?

Asked by Eric Heerdt
Posted Thu, 02/07/2013 - 10:22
Edited Thu, 02/07/2013 - 11:55

Tags:

9 Answers

Select your preferred way to display the comments and click "Save settings" to activate your changes.
1.
Helpful? 0

Eric, Recommend pre-painted aluminum angle flashing. The top (horizontal) face of the 90 degree angle should be at least 5" wide to extend completely over the 4" of foam, and over the foundation wall (under the sill). This then has your flashing performing double duty: protecting the foam from UV rays of the sun, and serving as a termite shield for any termites that bore up from the ground through the foam. Use your backfill soil to hold the bottom of the flashing in place.

Answered by James Riggins
Posted Thu, 02/07/2013 - 13:09

2.
Helpful? 0

You could metal-flash to the bottom of the insulation or if all you need is 8", you could use Energy Edge forms, http://www.certainteed.com/Products/340523.

Answered by Armando Cobo
Posted Thu, 02/07/2013 - 13:10

3.
Helpful? 0

In addition, This house will be built in southern Iowa and will have a full basement

Answered by Eric Heerdt
Posted Thu, 02/07/2013 - 13:27

4.
Helpful? 0

Eric,

I am considering using one of these coatings from Styro industries (http://styro.net/FoundationandICFCoatings.html) when I do a retrofit on a small house I own.

Do you have termites in southern Iowa? If so, the recent termite discussion might be useful to you.
Lucy

Answered by Lucy Foxworth
Posted Thu, 02/07/2013 - 16:59

5.
Helpful? 0

Eric,
The following article contains a list of 11 different materials that can be used to protect the above-grade portion of rigid foam insulation installed on the exterior of a basement wall:
How to Insulate a Basement Wall

Answered by Martin Holladay, GBA Advisor
Posted Fri, 02/08/2013 - 05:22

6.
Helpful? 0

Is there a height limitation in usa codes for house finish vs grade level ??

Answered by Jin Kazama
Posted Fri, 02/08/2013 - 11:43

7.
Helpful? 0

Is there a recommended amount to extend the protection below grade to protect from insects?

Answered by Aaron Gatzke
Posted Sun, 02/10/2013 - 18:56

8.
Helpful? 0

Jin,
Q. "Is there a height limitation in USA codes for house finish vs grade level?"

A. According to the 2009 IRC, section R404.1.6, "Height above finished grade. Concrete and masonry foundation walls shall extend above the finished grade adjacent to the foundation at all points a minimum of 4 inches (102 mm) where masonry veneer is used and a minimum of 6 inches (152 mm) elsewhere."

Because of the potential of rot due to splashback, I think it's a good practice to have the lowest wooden components of a building at least 8 inches above grade. Twelve inches is even better.

Answered by Martin Holladay, GBA Advisor
Posted Mon, 02/11/2013 - 09:17
Edited Mon, 02/11/2013 - 09:19.

9.
Helpful? 0

Aaron,
Q. "Is there a recommended amount to extend the protection below grade to protect from insects?"

A. Insects are capable of squeezing through very small cracks and seams. I don't think there is any way to guarantee that a below-grade layer of material will keep out insects. The insects will be behind the barrier and inside your house before you ever notice. The only way you can be sure insects won't enter is to have some type of inspection area that you can check regularly.

Answered by Martin Holladay, GBA Advisor
Posted Mon, 02/11/2013 - 09:22

Other Questions in Green building techniques

Flat roof insulation

In Energy efficiency and durability | Asked by Angela M | Nov 22, 13

Large structure with sealed attic / fiberglass

In Green products and materials | Asked by W Ahrens | Oct 22, 14

Spray foam over XPS on external wall

In Energy efficiency and durability | Asked by Jeff M | Oct 22, 14

How does the attic fan work? And can you use it in the winter?

In General questions | Asked by Aleasha Jeffries | Oct 22, 14

Double wythe CMU vs. Thermomass

In Green building techniques | Asked by leo kloop | Oct 22, 14
Register for a free account and join the conversation


Get a free account and join the conversation!
Become a GBA PRO!