Anyone with ICF building experience?

[dalola]

I built my last 2 houses with ICF's. My brother and I did the install of the blocks, then hired an expert contractor to do the bracing and the pour. I used polystyrene forms vs the Nexcem you're looking at. Nexcem wasn't even available 10 years ago when I did the 1st house. I know, because I went to 2 Int'l builders shows, 2 years in a row, and never saw them. Saw 47 other ICF manufacturers, but nothing using Nexcem type materials. Not saying they aren't any good, just uncertain that their product hasn't had a history of proven performance yet.

I looked at the Nexcem website to learn about them, and while they may be satisfactory, I have some concerns that you might want to consider:
* The Nexcem product appears to have much "thinner" walls on the block than poly ICF's. Means less R value (confirmed on their website) and probably requires more bracing during the concrete pour than poly ICF's.
* I question the "load" the exterior of the form to carry the weight of cabinets filled with dishes. The website says you can screw anywhere on the form, which implies flexibility of subsequent materials hanging on the wall. Based on my review of their construction and materials used in the forms, I doubt the exterior of the form will hold anything but a picture. And do they require tap con screws vs drywall screws? Mortar is not a substantial load bearing material. It is a bonding material when wet. Chips away easily when dry.
* Their forms are much smaller than poly forms, meaning you have more blocks, and more labor to install them. Thus more $$$. Typical poly forms are 48" long x 16" high x varying depths based on your needs. Nexcem blocks are 24"-36" long x 12" high x varying depths.
* I don't care for their engineering of the block to hold rebar, which is an essential element to a strong wall. In their blocks the rebar will definitely bend, and move during the pour, giving you inconsistent strength throughout the finished wall.
* From their website it looks like there are only 2-3 attachment points when stacking the blocks. Poly blocks have 40+ on a 48" long block. Means you'll have lots of "minor leaks" with Nexcem during the pour with 8 slump, and likely a lot of concrete stains and runs on the inside and outside of the Nexcem forms. If you're planning on having any of the inside walls left "naked", I suspect you won't like the looks of the wall. And you have an increased probability for blow outs during the pour.
* ALL ICF forms require pre-planning for elec runs, wall conduits for mechanical hook ups, etc. Cutting a 20-30' channel for elec in each room with the Nexcem block will be like being caught in a dust storm in Iraq. Have you ever cut a piece of Hardy board? It's roughly the same type of material. It's a mess. Cutting a poly form is easy. I used an elec chainsaw to cut the channels. Romex fit in nicely in the channel and the styro secured it by friction.
* I'm not saying Nexcem isn't a good block, but you'll be hard pressed to find a good-excellent installer. And believe me, there are numerous tricks of the trade to get a really good install. (too many to list here) I'd suggest you talk to at least 2 if not 3 installers to discover their skill level and knowledge of installing THIS block (not poly block). Because I suspect many installers will have poly block experience, will assume they can install this type of block the same way. I beg to differ.
*Every building product has its own trade-offs. Poly forms have their own drawbacks. You just have to know what they are and can you compensate for them (like elec channels, and location of conduits for mechanical hook ups thru walls)
* The Nexcem R value is far less than a comparable poly ICF form. My walls (6" concrete internally) are R-50.

Please understand....I'm not poo-pooing the Nexcem block. I've never seen it up close and personal. But from the website pictures, descriptions, etc, these are the concerns I have on the info provided.

Sorry this is so long of a post, but "you asked for it"! :thumbsup:

Good info Duffer, appreciate it! Experience is the best resource. Which brand system did you go with? I'd like to look into it.

What did you think of the Bautex system? Seems to be the "latest/greatest" take. Faswall seems identical to Nexcem, and Faswall has a decent history, for what it's worth.

My current thinking is all wood inside (little or no drywall), to at least "look" like a log home, and stone veneer on the outside, so raw wall finish look is of no importance.

 

[duffer]

I chose Amvic ICF's for both houses. I liked their interlocking stacking system (think egg crate), consistency of form construction, and options of forms, esp T's, corners, brick ledges, etc.

Took a quick look at Bautex. I like that less than the Nexcem product to be honest.

 

[rogerius]

We are in process of building ourselves an ICF house (1800sqft, bungalow with a walkout basement). After attending a one day ICF training we choose AMVIC 3.30 which has 3.25" thk foam on both sides. No blowouts during the pours, perfect alignments, very happy how went. No cons using this brand. All the info can be found on their site: specifications, building manuals, codes, etc. The R value is higher because of the thicker foam. Majority of the brands has only 2.5" thk.

 

[rogerius]

I built my last 2 houses with ICF's. My brother and I did the install of the blocks, then hired an expert contractor to do the bracing and the pour. I used polystyrene forms vs the Nexcem you're looking at. Nexcem wasn't even available 10 years ago when I did the 1st house. I know, because I went to 2 Int'l builders shows, 2 years in a row, and never saw them. Saw 47 other ICF manufacturers, but nothing using Nexcem type materials. Not saying they aren't any good, just uncertain that their product hasn't had a history of proven performance yet.

I looked at the Nexcem website to learn about them, and while they may be satisfactory, I have some concerns that you might want to consider:
* The Nexcem product appears to have much "thinner" walls on the block than poly ICF's. Means less R value (confirmed on their website) and probably requires more bracing during the concrete pour than poly ICF's.
* I question the "load" the exterior of the form to carry the weight of cabinets filled with dishes. The website says you can screw anywhere on the form, which implies flexibility of subsequent materials hanging on the wall. Based on my review of their construction and materials used in the forms, I doubt the exterior of the form will hold anything but a picture. And do they require tap con screws vs drywall screws? Mortar is not a substantial load bearing material. It is a bonding material when wet. Chips away easily when dry.
* Their forms are much smaller than poly forms, meaning you have more blocks, and more labor to install them. Thus more $$$. Typical poly forms are 48" long x 16" high x varying depths based on your needs. Nexcem blocks are 24"-36" long x 12" high x varying depths.
* I don't care for their engineering of the block to hold rebar, which is an essential element to a strong wall. In their blocks the rebar will definitely bend, and move during the pour, giving you inconsistent strength throughout the finished wall.
* From their website it looks like there are only 2-3 attachment points when stacking the blocks. Poly blocks have 40+ on a 48" long block. Means you'll have lots of "minor leaks" with Nexcem during the pour with 8 slump, and likely a lot of concrete stains and runs on the inside and outside of the Nexcem forms. If you're planning on having any of the inside walls left "naked", I suspect you won't like the looks of the wall. And you have an increased probability for blow outs during the pour.
* ALL ICF forms require pre-planning for elec runs, wall conduits for mechanical hook ups, etc. Cutting a 20-30' channel for elec in each room with the Nexcem block will be like being caught in a dust storm in Iraq. Have you ever cut a piece of Hardy board? It's roughly the same type of material. It's a mess. Cutting a poly form is easy. I used an elec chainsaw to cut the channels. Romex fit in nicely in the channel and the styro secured it by friction.
* I'm not saying Nexcem isn't a good block, but you'll be hard pressed to find a good-excellent installer. And believe me, there are numerous tricks of the trade to get a really good install. (too many to list here) I'd suggest you talk to at least 2 if not 3 installers to discover their skill level and knowledge of installing THIS block (not poly block). Because I suspect many installers will have poly block experience, will assume they can install this type of block the same way. I beg to differ.
*Every building product has its own trade-offs. Poly forms have their own drawbacks. You just have to know what they are and can you compensate for them (like elec channels, and location of conduits for mechanical hook ups thru walls)
* The Nexcem R value is far less than a comparable poly ICF form. My walls (6" concrete internally) are R-50.

Please understand....I'm not poo-pooing the Nexcem block. I've never seen it up close and personal. But from the website pictures, descriptions, etc, these are the concerns I have on the info provided.

Sorry this is so long of a post, but "you asked for it"! :thumbsup:

Just wondering what is the thickness of your wall to get R-50. Nexcem claims R-value of R 1.75 per inch.

 

[mikester]

Have not researched Blue-max, will look into it. Agree with most of your points.... I would also go 100% ICF to the roof. Not looking to DIY this, but want to be heavily involved. From what I've gathered so far, it seems ICF might add 5-10% vs std stick build. Seems more than worth it to me.






For sure I'd want an experienced contractor. Easy to see where things could go south in a hurry for the careless/clueless.



I could see DIY for someone with way more experience than me! As mentioned, I want to be involved, but only with an experienced ICF contractor. I suspect that will be the issue....finding a quality experienced contractor. Doesn't seem to be any of that style construction around here.

Re DIY - setting the forms isnt difficult...you just need a LOT of hands and bracing to get the pour done efficiently and quickly. The cement has to be vibrated properly to mix and flow right. Ive seen a lot of half a$$ed jobs with regular concrete form guys and you definitely dont want those kinds of problems. The guy I went with did a house down the road first and specialized in ICF. Id recommend seeing the contractor in action during a pour before you go with them. My guy used a LOT of steel braces with screw jacks every couple of feet to support the forms and everything came out nice and straight. Ive seen other contractors use 2x4s for bracing which seems to result in wonky form work.

 

[Diggin It]

I do a lot of low voltage wiring. Not much chance of running anything in exterior walls after the fact.

That's where the Wiremold 4000 comes in. Tremendous flexibility of wiring additions after the fact. If done right, it's nearly unnoticeable as it can be painted or even wall papered.

 

[montanadave]

I just completed building a small cabin on our place using the Faswall blocks. I'm very happy with the results and the building is rock-solid, but there is definitely a learning curve and the costs can escalate quickly. In my estimation, a reasonably accomplished DIYer could do just fine with them, assuming he takes his time, plans ahead, and doesn't get in a big hurry. Because the height of our structure had the top plate almost 30' above the footings (and I don't like heights), I quickly realized I was in over my head and was able to find a local contractor who was willing to step in, familiarize himself with the product, and carry the project across the finish line.

We added an additional 3" of exterior Roxul insulation, then metal siding, which pushed our wall thickness to almost 18". This, in turn, requires some careful planning and attention to detail when installing and trimming out windows. I would estimate the walls at around R-35. On the interior, we applied a natural lime plaster, which required application of a scratch coat and brown coat of stucco before the lime plaster. But it turned out terrific.

When using the Faswall block, be prepared for some pushback from some subs, as these blocks are designed to create a wall which is permeable to water vapor. As almost all current building practices have the goal of creating as 'tight' a building envelope as possible, having a 'breathing' wall makes insulation and HVAC guys crazy. There's a method to the madness, but it sometimes takes a while to explain what the goal is.

The blocks work well, but it's not like stick-framing and, as others have noted, whenever you rock the boat there's a cost in both time and dollars as folks get up to speed.

 

[grsthegreat]

As an electrician I HATE that stuff. Ive wired a lot of it and I used a special hot knife to cut Channels to run the romex and metal boxes for outlets. Very labor intensive to wire, and I charged a lot to go the work. Makes a nice finished product, but you can forget ever adding circuits or moving an outlet or switch later on.

 

[dalola]

We are in process of building ourselves an ICF house (1800sqft, bungalow with a walkout basement). After attending a one day ICF training we choose AMVIC 3.30 which has 3.25" thk foam on both sides. No blowouts during the pours, perfect alignments, very happy how went. No cons using this brand. All the info can be found on their site: specifications, building manuals, codes, etc. The R value is higher because of the thicker foam. Majority of the brands has only 2.5" thk.

Good to hear from another happy Amvic customer. Looks like a great product, from what I've learned so far.

I just completed building a small cabin on our place using the Faswall blocks. I'm very happy with the results and the building is rock-solid, but there is definitely a learning curve and the costs can escalate quickly. In my estimation, a reasonably accomplished DIYer could do just fine with them, assuming he takes his time, plans ahead, and doesn't get in a big hurry. Because the height of our structure had the top plate almost 30' above the footings (and I don't like heights), I quickly realized I was in over my head and was able to find a local contractor who was willing to step in, familiarize himself with the product, and carry the project across the finish line.

We added an additional 3" of exterior Roxul insulation, then metal siding, which pushed our wall thickness to almost 18". This, in turn, requires some careful planning and attention to detail when installing and trimming out windows. I would estimate the walls at around R-35. On the interior, we applied a natural lime plaster, which required application of a scratch coat and brown coat of stucco before the lime plaster. But it turned out terrific.

When using the Faswall block, be prepared for some pushback from some subs, as these blocks are designed to create a wall which is permeable to water vapor. As almost all current building practices have the goal of creating as 'tight' a building envelope as possible, having a 'breathing' wall makes insulation and HVAC guys crazy. There's a method to the madness, but it sometimes takes a while to explain what the goal is.

The blocks work well, but it's not like stick-framing and, as others have noted, whenever you rock the boat there's a cost in both time and dollars as folks get up to speed.

Good info, good to hear you're happy with the Faswall system. Any pix you can share?

As an electrician I HATE that stuff. Ive wired a lot of it and I used a special hot knife to cut Channels to run the romex and metal boxes for outlets. Very labor intensive to wire, and I charged a lot to go the work. Makes a nice finished product, but you can forget ever adding circuits or moving an outlet or switch later on.

I can see that being a PITA. You'd think someone would come up with a better way to accommodate elec & plumbing for ICF's... Maybe in 5 more years.... :confused3:

 

[grsthegreat]

the only other issue i have is i wonder about fumes if there's a fire. The smell when i burn a trough for wire is awful.... but there are no windows or doors in at that time so air flow is good. I once accidentally left a PVC pipe in my hot box too long when a contractor sidetracked me while i was heating the pipe. the smoke and smell from that cleared out the entire job site for 30 minutes. Those odors MUST be toxic