EIFS and exterior foundation insulation

Dave Taurinskas · 05-28-2009, 05:37 AM

Could someone clarify EIFS? I have had a contractor who installs exterior foundation insulation tell me that any exterior insulation with the stucco or masonry looking finish is EIFS. I have been running into a lot of foundations finished with an Acoona type insulation system and a some with the ridgid "exposed aggregate" panels, both over poured concrete or block. Is this type of exterior insiulation system a problem when put over concrete or block? Three contractors have told me it is not a problem over masonry products other than if it is deteriorating it may lose it's insulating value.

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**Jerry Peck** · 05-28-2009, 05:52 AM

Dave,

As I recall, EIFS needs to terminate above grade. So, if they are calling that EIFS ... it is a problem.

Scott P. can clarify and add more information as he knows more about EIFS than I do.

**Scott Patterson** · 05-28-2009, 07:06 AM

Originally Posted by Dave Taurinskas

Could someone clarify EIFS? I have had a contractor who installs exterior foundation insulation tell me that any exterior insulation with the stucco or masonry looking finish is EIFS. I have been running into a lot of foundations finished with an Acoona type insulation system and a some with the ridgid "exposed aggregate" panels, both over poured concrete or block. Is this type of exterior insiulation system a problem when put over concrete or block? Three contractors have told me it is not a problem over masonry products other than if it is deteriorating it may lose it's insulating value.

EIFS is the acronym for Exterior Insulation Finish System, it is a wall cladding and had nothing to do with foundation insulation.

The problem with having panels of whatever material over CMU or poured concrete walls is that you can not see termites or other critters between the panels and the wall. I hate foundation insulation for that simple reason and it is also not allowed by many AHJ's for this reason as well.

I think that this is really more of a pest issue than an EIFS issue.

**Jerry Peck** · 05-28-2009, 09:36 AM

Scott,

If we are going with that as "foundation insulation", then (and for the reason you mentioned) the installation must meet this:
- From the 2006 IRC. (underlining and bold are mine)
- - R403.3.4 Termite damage. The use of foam plastic in areas of “very heavy” termite infestation probability shall be in accordance with Section R320.5.

- - R320.5 Foam plastic protection. In areas where the probability of termite infestation is “very heavy” as indicated in Figure R301.2(6), extruded and expanded polystyrene, polyisocyanurate and other foam plastics shall not be installed on the exterior face or under interior or exterior foundation walls or slab foundations located below grade. The clearance between foam plastics installed above grade and exposed earth shall be at least 6 inches (152 mm).
- - - Exceptions:

- - - - 1. Buildings where the structural members of walls, floors, ceilings and roofs are entirely of noncombustible materials or pressure-preservative-treated wood.
- - - - 2. When in addition to the requirements of Section R320.1, an approved method of protecting the foam plastic and structure from subterranean termite damage is used.

- - - - 3. On the interior side of basement walls.

But I wanted you to address the EIFS reference first, because EIFS are required to terminate 6" above grade.

Dave Taurinskas · 05-28-2009, 11:23 AM

Thanks for the input so far!

What I am seeing here in Minnesota is the foundation walls insulated with a crushed fiberglass approx 2 inches thick (attached with fasteners) then a membrane of fiberglass mesh with a masonry looking coating over all of that, or the crushed fiberglass or ridged foam insulation with treated plywood, panels, or some stiff coating over that then coated with a masonry looking product. This product starts under the siding and goes into the ground about 6 inches. Sometimes it goes much deeper possible to the footings??? Many contractors did this because it was cheaper than furring out and insulating the inside of the basements. But is it a problem over concrete? ...and What problems does it cause?

**Jerry Peck** · 05-28-2009, 12:28 PM

Originally Posted by Dave Taurinskas

This product starts under the siding and goes into the ground about 6 inches. Sometimes it goes much deeper possible to the footings??? Many contractors did this because it was cheaper than furring out and insulating the inside of the basements. But is it a problem over concrete? ...and What problems does it cause?

Superhighway for termites to enter the structure sight unseen!

I don't recall learning anything about fiberglass being itchy to termites and thus acting as a deterrent.

"Many contractors did this because it was cheaper than" ...

Scarier words have seldom been said "because it was cheaper than"!

Dave Taurinskas · 05-28-2009, 08:22 PM

Termites will go through the block or pour concrete?

Ted Menelly · 05-28-2009, 08:46 PM

Originally Posted by Dave Taurinskas

Termites will go through the block or pour concrete?

If there is a crack and I forget off hand how small but it is pretty minute. Formosan termites will eat through brick and block with the slightest crack to get through

Jim Schwarz · 05-29-2009, 04:43 AM

I have heard of some sort of underground insulation system in reference to EIFS. It's worth contacting whoever the contractor is saying is the EIFS manufacturer for this specific system and finding out more about it directly from them.

**Jerry Peck** · 05-29-2009, 05:57 AM

Originally Posted by Ted Menelly

If there is a crack and I forget off hand how small but it is pretty minute. Formosan termites will eat through brick and block with the slightest crack to get through

Yes, termites can go through a very small crack, I think it was less than 1/16".

No, Formosan termites do not eat brick or block, they just find their way through cracks.

Ed Voytovich · 05-29-2009, 10:49 AM

Dow Blueguard rigid insulation board is termite resistant and made for use below grade and under slabs.

http://www.earthcrafthouse.com/docum...abnapril07.pdf

**Jerry Peck** · 05-29-2009, 11:19 AM

Originally Posted by Ed Voytovich

Dow Blueguard rigid insulation board is termite resistant and made for use below grade and under slabs.

www.earthcrafthouse.com/documents/abn/abnapril07.pdf

That does not, however, state that you can use it where the code says not to, or treat it as required when used.

From the top of the right column: (bold and underlining are mine)

"Designed to be used in conjunction with a total insect management program, in extensive field testing, it has proven to resist termites tunneling through the foam."

That is what Exception 2 is for.

Originally Posted by Jerry Peck

- - - - 2. When in addition to the requirements of Section R320.1, an approved method of protecting the foam plastic and structure from subterranean termite damage is used.