Insulated Concrete Forms 1

[jie5]

Anyone have any experience with ICF's? I am currently in the concept phase of a project and looking for some pro's and cons of the product.

 

[dik]

The Portland Cement Assn has a couple of publications on these.

Dik

 

[Splitrings]

I have been involved with only one project using ICF's. It was a 20'x20x12' tank. Biggest problem we had was the amount of reinforcing we needed to use. These forms are intended for lightly reinforced walls. Vertical reinforcing is not so much a problem, other than you have to lift each form over the top of the reinforcing. I believe the ones we used were intended for 12" horizontal bar spacings. A benefit is the insulating factor. This project was in the middle of January in New England. Once the project is complete the insulation needs to be protected from damage if it is exposed.

 

[smb4050]

Is it for a commercial or residential application? Concrete wall design utilizing ICF is a more complicated with greater attention needed to connection details. With all newer material and/or applications, the installing contractor's experience is critical. ICF manufacturer's have a more liberal view on what or how it can be used. Form allignment, concrete placement and consolidation, and building envelope details, particularly below grade, technics are more complicated. I use to get copies of ICF Builder magazine which was a good source of information. I don't get it anymore, so I don't know if it is still published. As noted above, PCA has publications on the topic, and HAHB's Research Center and PCA have jointly

 

[hawkaz]

There are many different types of ICF- Make sure you understand the system that will be used.

General recommendations:
1. Require a contractor with experience using that particular product
2. Don't hang anything (i.e. canopies or balloon type framing) from the face of these walls
3. It is preferable to make these walls cladding, and have the framing supported independently.
4. Require SSI and SSO
5. If you use a core type ICF (4" or 6" holes at 15" plus or minus on center), it is very difficult to install epoxy anchors in the face without blowing out the cell. To reiterate #2- try to avoid surface mounting connections.

 

[msquared48]

Biggest problem I have run into is to get the written documentation that the products have been tested and rated buy a testing agency. I work with nothing less than rated ER report values or comparable.

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[msquared48]

Oh, I also am in a high seismic zone, and some of the products are not rated for my area.

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[JAE]

Keep in mind ICF's are just forms. They are not your structural system. The walls within the ICF's are still just concrete per ACI or whatever code governs. They aren't rocket science from the structural design perspective.

 

[Brad805]

I think ICF are great for foundation and small residential developments, but I am not a huge fan of these for commercial projects. The biggest downside is you wind up with two surfaces to finish and the beautiful durable product is totally hidden. I can get the exact same thermal performance and have two durable surfaces using a precast concrete sandwich panel. If you look closely at the costs, precast concrete panels can work out to be the same cost or less.

Another thing, don't point out to your field inspectors how they anchor on the walkways for construction. I explained to one of our guys that they only use #10 pan head screws in the plastic ties, and he still is not thrilled to know that.

Brad

 

[BAretired]

I agree with JAE that, from a structural perspective, the concrete wall is the only part of interest. Not sure why m^2 would need forms to be rated.

BA

 

[msquared48]

BA amnd JAE:

ICF's, in themselves, are styrofoam forms, true.

However, when you fill them with concrete and steel, they become structural elements - walls (some perforated), beams, columns and lintels. I prefer to work with those that are rated.

If they are not rated, then they need to be analyzed structurally for the application and location of use.

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[concretemasonry]

The rating separates the real supplies with standards, details, installation instructions and technical support based on testing from the huge amount of form manufacturers that just make an ICF with a cute name when they are not doing their main business, which is making foam meat trays for Walmarts and similar retailers.

The lower end systems are usually used by people that just dump the forms full, let them bulge, deform or move at corners and promote poor concrete placement and never seem to mention thta pumping can be a superior placement method.

There are some very good suppliers with a wealth of experience and technical assistance to designers that bother to go to get their system tested and approved.

It still bothers me that they use EPS foam instead of XPS foam, but that fits the system although it does limit the forming and bracing.

Dick

Engineer and international traveler interested in construction techniques, problems and proper design.

 

[JAE]

Mike....after you fill an ICF with concrete - the ICF itself isn't a structural element. It is just a form that supplies some level of connectivity for siding, sheathing, etc.

All the walls, beams, lintels, etc. that are FORMED by the ICF are still just concrete walls, beams, and lintels.

 

[msquared48]

That's correct JAE. The RC is the structure, not the forms.

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask