ICF Interior

[dereckbc]

Bought some property for retirement and investigating building using ICF (Insulated Concrete Forms).

Have not looked to deeply on the web and cannot find the answer some of you should know if you have worked on one.

How are the exterior walls finnished inside?

I assume something like furrow strips are installed on something like 24 inch centers to make a space for electrical raceways, LV wiring, and connecting sheetrock too like a cinderblock construction... Am I all wet?

I assume interrior walls are conventional stick built framing?

Anything else out of the ordinary other than it is expensive to move doors, windows, extensions

 

[cadpoint]

I beleieve theres two designs to three design of this type of construction

Concrete, foam, concrete

Concrete, foam (varies which is where)

Specical mix concrete wall

Low profile studs or full studs,w/ sheet rock, hope for the full studs. Sometimes theres no furred out wall

If you can call ahead and order a receptical in, by all means - Call!

 

[Dennis Alwon]

Bought some property for retirement and investigating building using ICF (Insulated Concrete Forms).

Have not looked to deeply on the web and cannot find the answer some of you should know if you have worked on one.

How are the exterior walls finnished inside?

I assume something like furrow strips are installed on something like 24 inch centers to make a space for electrical raceways, LV wiring, and connecting sheetrock too like a cinderblock construction... Am I all wet?

I assume interrior walls are conventional stick built framing?

Anything else out of the ordinary other than it is expensive to move doors, windows, extensions

You can do what you want but the one I did was stucco in and out. The electrical boxes were mounted in the forms by the ICF building co. The box locations are planned at an early stage so that the forms get poured with the proper boxes installed. A conduit was installed to sleeve the nm to the box.

 

[SmithBuilt]

How are the exterior walls finnished inside?

I assume something like furrow strips are installed on something like 24 inch centers to make a space for electrical raceways, LV wiring, and connecting sheetrock too like a cinderblock construction... Am I all wet?

I assume interrior walls are conventional stick built framing?

No studs or furring strips.

All the forms I've seen have a plastic strip that is 1" wide,vertical and every 8" on center for screwing sheetrock directly on the ICF.

You have to make a groove in the foam and put the wire deep in the groove. I have used a chainsaw with a wooden block clamped on the bar for a depth gauge.

The interior walls are normally stick built.

I have built and wired 3 homes with ICF walls for the basement. I currently live in the last one I built. I would like to do a whole house with ICF used for the exterior walls. Not just the basement.

 

[SmithBuilt]

You can do what you want but the one I did was stucco in and out. The electrical boxes were mounted in the forms by the ICF building co. The box locations are planned at an early stage so that the forms get poured with the proper boxes installed. A conduit was installed to sleeve the nm to the box.

I have seen conduit run for the wires but have never done it that way myself.

The forms I use are thick enough to install boxes after the walls are poured. I cutout the foam and tapcon the box directly to the concrete.

 

[wbalsam1]

No studs or furring strips.

All the forms I've seen have a plastic strip that is 1" wide,vertical and every 8" on center for screwing sheetrock directly on the ICF.

You have to make a groove in the foam and put the wire deep in the groove. I have used a chainsaw with a wooden block clamped on the bar for a depth gauge.

The interior walls are normally stick built.

I have built and wired 3 homes with ICF walls for the basement. I currently live in the last one I built. I would like to do a whole house with ICF used for the exterior walls. Not just the basement.

What you've outlined here is exactly my experience. Remember to keep the cables back 1 1/4 from the plane of the surface, too.

 

[dereckbc]

All the forms I've seen have a plastic strip that is 1" wide,vertical and every 8" on center for screwing sheetrock directly on the ICF.

You have to make a groove in the foam and put the wire deep in the groove. I have used a chainsaw with a wooden block clamped on the bar for a depth gauge.

Thank you that is interesting. So I guess if you have to move or add a circuit, sheet rock has to come down?

Do you use a low profile box on the exterrior walls, or just dig out some foam to make room for the box?

 

[alfiesauce]

The blocks I've seen have had metal strips integrated into them that all line up as 'studs' when they are put together. We hammer drilled 1 1/2" metal boxes to the concrete once all poured and then cut narrow grooves straight up from the boxes to the joists and/or rafters to push the nm into. Really as long as you are away from the metal straps that will be used for fastening the drywall to the wall with seems no different then using stacker straps on shallow walls.

If you have a lot of this type of work coming up I believe there are companys that make a heavy duty heat gun with a bar that you can use to make your grooves, but i've also seen the chain saws, skill saws, sawsalls, or even in small applications just a knife and screwdriver be used.

 

[480sparky]

Thank you that is interesting. So I guess if you have to move or add a circuit, sheet rock has to come down?

Pretty much.

Do you use a low profile box on the exterrior walls, or just dig out some foam to make room for the box?

I dig out the foam and Ramset the box right to the 'crete. Use appropriate-depth mud ring.

 

[alfiesauce]

Thank you that is interesting. So I guess if you have to move or add a circuit, sheet rock has to come down?

Do you use a low profile box on the exterrior walls, or just dig out some foam to make room for the box?

Add a circuit - drywall removal or surface. This is not a renovation friendly installation at all.

Depending on if they are furring out or not. I've always been able to use an 1 1/2" deep box, so either 1900 with mudring or 8B or whatever you need for box fill.

 

[dereckbc]

Add a circuit - drywall removal or surface. This is not a renovation friendly installation at all.

I knew it was not renovation friendly with respect to door, window, etc but was not sure about electrical. I won't be designing ICF's, not my thing, but I am toying around with the idea for what I think will be my last house to build and retire in until the man calls me to play the great golf course upstairs.

 

[George Stolz]

I've only dabbled, but I would avoid it like the plague, myself. I'd take a regular concrete structure first.

My dream is to build and retire in a Cast Earth home, myself. I have been inside the home shown in Greeley, CO, and it is supremely attractive. The exposed rock makes use of direct sunlight gain to heat the house, and properly sized soffits keep the sunlight off the stone in the summer. With ICF, I don't see how direct-gain is possible, the mass of the concrete is encased in styrofoam.

Looks like that house is for sale, too, Dereck.

 

[infinity]

What you've outlined here is exactly my experience. Remember to keep the cables back 1 1/4 from the plane of the surface, too.

The cables are only required to be 1.25" from the edge of a framing member not the surface of the finish. The grove only need be deep enough to get the cable flush with the edge of the foam if it was 1.25" away from the edge of the framing member.

 

[iwire]

The cables are only required to be 1.25" from the edge of a framing member not the surface of the finish. The grove only need be deep enough to get the cable flush with the edge of the foam if it was 1.25" away from the edge of the framing member.

I agree with Rob.

 

[wbalsam1]

The cables are only required to be 1.25" from the edge of a framing member not the surface of the finish. The grove only need be deep enough to get the cable flush with the edge of the foam if it was 1.25" away from the edge of the framing member.

I'm speaking of the Residential Code of NYS which is based on the IRC (with NY amendments). In our Table E3702.1, non-metallic cable is permitted to be installed in grooves as per this provision:
"Where installed in grooves, to be covered by wallboard, siding, paneling, carpeting or similar finish, wiring methods shall be protected by 0.0625-inch-thick steel plate, sleeve, or equivalent or by not less than 1.25-inch free space for the full length of the groove in which the cable or raceway is installed."

This is similar to 300.4(E)

 

[dereckbc]

I've only dabbled, but I would avoid it like the plague, myself. I'd take a regular concrete structure first.

Why George? I live in TX and we don't get those massive outbreaks of soap bubbles you Yankee guys call snow.

 

[dereckbc]

Well I thought I would follow up. Met with a builder who does ICF construction. Went out and seen one home under construction and one model.

As most of you said there are several options with the exterior inside wall finish, all depends on how much you want to spend. Everything from plastic strip to secure drywall, up to traditional 2 x 4 stick framing.

The model home really impressed me. It was a 10-inch ICF vs 8-inch. The very first thing I noticed when I walked in was the silence was deafening. Next I noticed all the windows had about a 6-inch ledge which my wife really liked as she like to put bling-blings to decorate. The next thing you notice is the comfort.

I commented on how comfortable the interior was and they informed the home had a geo-thermal heat pump, and they showed me the electric bills over the last year. Highest was in July/August was $37. Granted the home is a model and does not get the use a real home would, but for a 3360/ft2 home in TX for just moderate HVAC and minor lighting was impressive. R values for this home were impressive, greater than R-40 in the walls, and 50+ in the attic. They also incorporated window placement and Sun Tube lights so lighting during the day is minimal.

Anyway I was impressed, and seriously considering using the construction method when and if I get another chance.

 

[DonaldKMorgan]

Approved wiring methods for ICF installations

Approved wiring methods for ICF installations

I have several questions concerning wiring methods for Insulated Concrete Forms (ICF). First; can you use standard non-metallic boxes attached with tap cons after foam removed to allow installation? Second; I understand the method of using a chain saw to cut a groove for single or possibly dual wires, but what if you are installing a four gang box with 12 #12 wires? Third; Since the wiring is to be installed in Styrofoam are there any derating rules for the NM cable? Fourth; How is the wire secured in the cut channel and at what intervals?

 

[George Stolz]

I have several questions concerning wiring methods for Insulated Concrete Forms (ICF).

Lesson #1: Run.

First; can you use standard non-metallic boxes attached with tap cons after foam removed to allow installation?

Doesn't work. Use four square boxes and liquid nails.

Second; I understand the method of using a chain saw to cut a groove for single or possibly dual wires, but what if you are installing a four gang box with 12 #12 wires?

My cohort used a router. Burned through three routers, but it worked well.

Third; Since the wiring is to be installed in Styrofoam are there any derating rules for the NM cable?

Yes, 334.80. And don't forget the 1.25" rule (300.4)

Fourth; How is the wire secured in the cut channel and at what intervals?

A staple or a nail sideways, and spray foam insulation.