Best ICF Blocks??? Fox Block VS Lumber VS Perfect Block VS Nudura VS Build Block VS Quad Lock

Help us figure out the best ICF blocks to use for our renovation project. We've been comparing Fox Blocks vs Nudura vs Perfect Block, etc... all the foam insulated concrete form companies basically. In a perfect world where money is no object, I'd prefer to build the entire structure out of concrete just like I would with an earth sheltered house with a thermal mass wall modeling some of the earthship designs. What do you think? Frame the second two floors out of lumber and call it a day? Help! Every block company says their block is the best, but each have their nuances about them during installation right? We need opinions...

[@waynesheppard]

I built a custom 4000 sq ft 3 story home at 10K feet in Colorado, and learned a lot. The entire structure was concrete and formed foam, floors, walls, and roof. Started with ICFs at the walkout basement level, learned better, and redesigned top two floors completely. Very efficient even with 5x5 windows and 10 ft ceilings. Massive thermal loading with full depth concrete floors and electric on-demand water heaters for radiant floor heat. fun fact - Propane @ 10K ft elevation loses 40% BTUs before it hits the appliance, where it may lose another 10-20%. Fuel oil has similar performance drawbacks if at altitude. So at that location electric was/is far less costly than alternatives. I mention all this detail because building something that doesn't thoughtfully consider the climate, risks (wildfire? hurricanes? tornado? flood?) and how that might alter the design goals doesn't make sense.(to me) I get why builders don't, they rely on cookie-cutter solutions so their subs and trades are efficient. There are also building codes to consider in some places that are outdated and arbitrarily enforced, but that must be followed regardless. As well as wind and snow loading. Ok, this is maybe outside of your direct question regarding the 'best' way to build a box, but you mentioned alternative building too, so here you go. Here are some points to consider - (this would be a very different list in a hot climate btw) A major consideration is thermal breaks, and ensuring there are as few of those as is possible. In a perfect world none, but there will be some, so be sure to include any in your heating/cooling sizing calcs. ICF vendors make claims regarding thermal mass. Since the concrete is *inside* the block insulation, ask yourself how the heat transfer takes place to load the mass (concrete) with thermal energy? Oops. If the insulation will allow heat to flow into the concrete, it will also allow flow to the outside. The insulation is the same thickness on both sides of the block so either there is no loading or there is heat leakage. In a cold climate you really want all the thermal mass *inside* the entire insulation envelope. Most ICFs require a complete cutout for lintels. Massive thermal breaks at every exterior door and window. Placing wiring and plumbing in ICFs isn't the 'hot knife through butter' panacea that is often claimed. Cutting across glued areas, concrete leakage, corners, electrical box depth limitations, and other surprises will consume much more labor than you'd think. Not a show stopper by any means, but unless you're doing it and therefore price your labor at 99 cents an hour like I apparently did, this stuff adds up to cost overruns and 'after the fact' surprises that are *very* hard to address. (not that it happened to me, but I've heard from others...) ICFs that have honeycomb walls have created some nightmares for folks that had fires, and were left with this strange structure that while it didn't fall down (Yay!) is perplexing to rebuild. It's also not a firewall obviously as once the foam melts away, it's got large holes, duh. The one home I personally saw that had this happen also revealed shockingly large sections of wall that had not been filled with concrete at all. Imagine the honeycomb with sections missing. The mud just didn't flow there for whatever reason, and vibration is dodgy with most ICFs, good way to cause blowouts if overdone. I've also seen unintended 'honeycomb walls' where the mud just didn't flow into the entire ICF cavity. If poured with smaller lifts this can be avoided, but mostly folks pour at least 8' walls at once so this is harder to detect. I've seen workers drop empty pop cans, trimmed foam, and other debris into walls thinking it doesn't matter cuz 'it's all gonna get poured nobody will see it'. This contributes to the void problem. Handling, cutting, and properly placing rebar isn't rocket surgery, but many get this wrong, and when it's wrong that negates a LOT of engineered structural integrity. Most common are not following the 30 diameter overlap rule, improper tying, and placing too close to foam on turns. The idea that you can have 'too much' bracing with ICFs is nonsense. Yes it's a PITA, but straight, square, and plumb is important as correcting later will come at the expense of either insulation, structural integrity, or interior space reduction to support the next floor level properly. Extra bracing is some very inexpensive 'oh shit' insurance imo. One idiot pumping too much too fast can cause blowouts and movement that 'shouldn't happen', and yet... Delivery of concrete and proper mix design is important. Yet you'll see a pump operator flashing "5 more gallons" to the truck operator to thin the mix so it doesn't get stuck in the pump, or from the crew placing the concrete if doesn't look like it's flowing well in the ICF wall cavity. If there was one thing I'd share with everyone everywhere working with almost any cementitious material it would be to get your hands on some Kel-Crete, and use it according to the instructions. Non-toxic magical stuff - kel-crete.com (not affiliated, just know it makes concrete more forgiving/better) ICFs present risks that are hard to detect, require more skills than most vendors admit to, and are not less expensive or faster by any measure. In the hands of the right builder, in the right climate, with the right trades with ICF experience, it they can be awesome. I personally haven't seen this place of rainbows and pots of gold, but then I've never seen a lot of things that must exist somewhere cuz they're on KZbin right?. I'd suggest you carefully assess the labor you have available as a key factor in deciding what 'best' looks like. If all you find are good framers, asking them to become instant experts of ICFs is going to be disappointing. If you can find a form and pour wizard, place insulating foam in the form on what will be the outside face to form your insulation envelope. Look at cutting slots to foam glue 2x4s for the cladding attachment points? Some variation of that theme will provide incredible multigenerational results if properly executed. Or fire rated stucco vs Hardy board directly on the foam insulation. Have fun and keep it simple, but not so simple it's not KZbin worthy. :) Can't wait to see what you decide.

[@matt-justice]

Best comment ever. I'm going to reread this a few times to digest... so you're suggesting internal mass loading walls with only insulation on the outside? Makes sense, when it's -20 below out, the woodstove or other supplemental heat would hold in the mass if not insulated well, vice versa on the outside shell.

[@waynesheppard]

@@matt-justice Yes, keep the heat source and thermal mass together, inside the insulation envelope. Unless you're going to do radiant floors (and that's a whole other rabbit hole I accidentally learned a lot about) or form and pour walls, you may not have much 'mass'. If that's so, not sure what the SIP options might be in your area, but worth a look if the site can support delivery.

[@tgallahar1537]

​@waynesheppard Awesome comment and write-up. I am in San Antonio so the climate is different that the cold of Colorado. We have looked at many ICF companies and have settled on Logix block. Our land is in the hill country and we almost went with a walk out basement but that would have been 6000 sqft. Lol. We have it a single floor at 3800 sq ft and yup I am going to stack the blocks myself and do as much as I can so I can get to your .99 cent an hour estimate. Wish me luck. Taz

[@MadLadsAnonymous]

One of the most valuable comments I've come across! Thank you for sharing the wisdom. Hope you see this and can answer a few questions: • Which Kel-Crete product did you use? Can we combine their Premium Liquid Admixture and the Kel-Prime? The Prime seems especially useful as an anti-fungal for exterior stucco/lime plastering. • For the ICF concrete pour, can the homeowner typically request specific qualities of the mix, like adding fibers (fiberglass and Helix Steel), PSI rating (5k for walls), and other stuff like Zypex self healing admixture? • Perfect Block suggests Rub-R-Wall waterproofing for the exterior and says this coating can take stucco straight on. Did you use anything like this? • Is it worth doubling up on exterior insulation with the Zip-R insulated flashing system (eg Rub-R-Wall > Zip-R > Stucco)

[@waynesheppard]

Some questions- Where are you building? I’m assuming you’ll pump the concrete for wall fill, what length pump boom will be required? (Shorter is better, as long as it will reach.) Most concrete facilities can’t/won’t accommodate additives that they don’t sell you at the plant. I wouldn’t trust them to get it right anyway, you’re solidly in the ‘pita customer’ category unless you blindly follow the salesman’s ‘suggestions’, but some things they can handle like an 8 sack pea gravel mix, everything else you’ll add onsite. Charles at Kelcrete is your dude for which product/application. Using kelcrete, your pump operator may flinch at how dry the mix looks, they are afraid off boom blockages and rightly so, but trust what Charles tells you will flow, it’s creamy and flows like butter with less water. I don’t think fibers are adding value in an ICF wall, but PVA for flatwork @ 1lb (iirc) per yard combined with high dose pozzolan will *eliminate* cracking in the right mix. 4K sq ft zero expansion joints and zero cracks, fully cured at around 8k psi. The are actually cracks of course, but they are at the micro level, so small as to keep the slab waterproof. University of Hawaii and Michigan did extensive research on this. In Japan they built 60 story buildings with 6” curtain walls and no steel with these ‘micro engineered’ mix designs. Ok, you’re not needing that extreme performance, I’m just saying. US ‘typical’ mud designs are horribly behind the science. You can reach me at bemorefreenow@gmail to speak more if you want. btw, with inflation, your hourly rate may gust as high as $1.20 now. 😊

[@nsgrossman]

Building with Perfect Block in Colorado. Love it. I recognize that this video is now 8 months old, but if you haven't pulled the trigger on a particular system, here are some answers to your concerns: Attaching to walls Tapcons work extremely well, though each hole has to be pre-drilled so it can be somewhat time consuming. If plaster, stucco, drywall, or tile are considerations, they can be applied directly to the block, no need for backers, mesh, or screws. Another option is to "hog out" a section of block on the inside of the wall using a router, then glue and/or screw a 2x4 into that section. This works well for railings on stairs or for kitchen cabinets that need extra strength but where a tapcon may not be practical. Continuous concrete I think you've covered this perfectly. If you've planned everything flawlessly this is probably better than the web structure offered by TPB. However, if you need to add a penetration after the pour (electrical box, hose bib, etc.) good luck drilling through it. With TPB those webs are super easy to drill through if needed. If for some reason you need to fill in a hole in the web, use foam to glue in a scrap piece. Bracing Hard to believe but true; no bracing is necessary. I was worried about blowouts on my first pour so I did a bit of bracing anyway. That proved to be completely unnecessary. I've since poured over 1000 blocks without any bracing at all. I've had two blowouts, both minor, where I had to "hog out" pieces of block to accommodate steel columns. If your blocks haven't been compromised in this manor you'll be fine. Alternatives I've had great experiences with TPB in terms of customer service. I was originally considering EF Block (a similar competitor) but when I called to schedule block delivery they couldn't commit to any sort of delivery window - not even a specific month! TPB on the other hand has been able to deliver blocks within days of payment. Another option is called Eterna, and I'm told that they're the originator of the ICCF product in the US. Their blocks are longer and thereby a bit harder to use, but they're cheaper and have a lower concrete consumption. Send me a DM if you'd like more info, happy to discuss.

[@dragon0085]

Hey I am building in CO and want some info on ICF, can I get in touch with you?

[@steed262]

I have built 2 home out of EF Block (same as the perfect block) the thing I really like about this system I was able easily able to customize the block to accommodate things like plumbing in the walls and changes to things like door and window locations.

[@victorrybak5859]

I've done 5 complete homes with iccf block (perfect block or EF block) with basements and it was a breeze, we installed the legder before the pour and use it for bracing as well and the floors come out laser striat. I started building home like thing in lincoln NE hopefully in the next 3 year thats all I will ever build.

[@keithdygert1120]

What’s the difference between EF block and TPB? Is one easier to get in the Midwest? Thank you.

[@jamesreinhardt3107]

I have built a 4k two story house out of icf, walk out basement with 15 foot ceiling for garage and shop. I did a lot of extra steps to eliminate as much thermal bridging in windows and truss attachment areas. I used a block called Stronghold. they were easy to use, and had a great mix of Nudura and fox pluses. i went with them for cost. did the house in two pours and switches from 8 inch block to 6 inch for the house. I used truss hangers for floor trusses so no ledger board or other holes needed in walls. I build houses for a living and wish more people would look at this option for basements as well as homes. Would enjoy talking more details if interested.

[@matt-justice]

Sounds like what I should’ve done… was thinking about that… when using 8inch for basement, couldn’t you just pour a ledge for floor trusses to sit on when it switches to 6inch?

[@ricinro]

Perfect block offers design possibilities like curved walls and some sculpting that is difficult with ICF and stick homes. The downside is that these structures are difficult to modify (like removing a wall for an extension) as cutting through rebar and concrete is much harder. If you think you may add to the structure at a later date then put in a provisional wall using lumber.

[@DrMJJr]

I’d use composite ICF block like Nexcem!!!!

[@andreycham4797]

Good point about termites another good point would be, for Maine, african elephant can not easily brake through solid fox concrete wall

[@justbob1581]

Have you guys heard of or checked out Rhino ICF's? I've been doing a ton of research myself for my first build, and I think that's the way I'm going to go because their system has far fewer seams, and the Styrofoam is also a little thicker, all for about the same price. Their webbing is also wider and thicker, making it even easier to install your subfloor before your pour, if so desired. The owner of the company has also answered the phone every time I called!

[@matt-justice]

Yes saw them a couple times, but don't know how this would go for DIY install without a crane... Area is remote, we're pretty much limited to using contractors with this system. I'd like to choose something to where if they don't show up, I can complete it myself.

[@jonathanmilton9753]

Put in a rain screen with 2x4 in the perfect block and then can put up the siding.

[@beardoe6874]

I looked at a lot of ICF manufacturers. While perfect block seems neat with the fire rating and attaching to it is not super simple, a conventional ICF just relies on a thin plastic "stud" which is a little bit scarry when you compare it to a wood stud. The one brand I found that I think offers the best of everything is Mikey Block. It's a screen grid like Perfect Block and they make it both with straight Styrofoam and as an ICCF (Perfect Block is an ICCF), so you can get the fire rating where you want but it doesn't have to be the whole building. A neat thing about Mikey Block is instead of stacking like Lego the way a conventional ICF stacks, or gluing together blocks like Perfect Block, it has slots top and bottom and when you place the blocks you key them together with a strip of OSB which acts like the conventional ICF plastic stud except horizontal. I think you probably should glue it together too but to me it seems like a clever solution where you can get a screen grid ICF or ICCF with "studs" for wall attachment. I guess the downside is OSB inside your ICF wall but I'm thinking about replacing the OSB strips with Trex or some other very stable composite wood type material. Mikey Block probably isn't for everyone. I bet a lot of people would look at the things I like about it and pick Fox or Nudura instead. Luckily I live close to the manufacturer. I'm going to go see their operation along with EF Block, Perfect Block and anything else close by. I think Nudura and others have made ICF nearly a commodity product and conventional ICFs are similar enough that a builder can take their pick. On the other hand, I think something like Mikey Block might be a little bit better. I like ICCF for several reasons. Fire resistance is one, less concrete to pour is another but I really don't want insects or rodents in my walls. ICCFs are made with EPS-crete which evidently bugs and rodents don't like to eat or burrow in to. As long as I keep the wall dry there should be no attraction for insects and in the desert, dry shouldn't be a problem. I'm going to do other stuff like plastic under my foundation to prevent rising damp and termite block strips as an extra barrier against any critter that develops a taste for EPS-crete but that's probably more driven by my (slight) paranoia than practicality. Another way I look at it is for a few thousand more, I can make a building that can probably survive 500+ years.

[@beardoe6874]

Oh, also thermal mass. Keeping it inside the wall is fine. You are always going to have thermal gradients across the outer insulation, concrete core and inner insulation so your concrete core temperature will be about 1/2 way between interior and exterior temperature. For me in the desert, between 76° and 116° should be around 96° but my wall is attached to my footer so I might get a little cooling there. In the winter between 70° and 30° is about 50° but ground temperature hovers around 65° so that might help with the heat. Any way, with a very tight envelope and an ERV/HRV unit, the interior insulation will not have too much heat loss winter or summer. With that said, ICF R-values are kind of bogus. I think they model their wall against a wall with no thermal mass over a seasonal climate. The performance is similar but no other calculation adds up to the advertised R-values.

[@BreezeofBliss]

Its October 2023, not sure how far into your renovation you are. Recommended ICF all 3 stories. It protects your house from rot, mold, moisture, termites, hurricanes, tornadoes, fire...Keep in mind that ICF homes need constant temp at all times. I know you are only asking about which brand of ICF blocks to use and if 2nd & 3rd floor should be ICF or not. However if you're looking for sustainable & energy efficient ideas for the remainder of the house, read below. (1) Flooring - Cork, Bamboo, Recycled rubber, or scored & stained concrete. Radiant floor heating. (2) Roof - Zinc strips on shingles to prevent mold, mildew, moss; 30 year weather wood shingle; radiant barrier before putting on shingles. select a color of shingle to reflect the sun's heat. Use soy-based insulation and blow it in under the eves instead of the ceiling floor. (3) Home Insulation - ICF blocks. Soy based insulation. Insulate East & West more than North & South (4) Efficient windows - Double glass windows; High visible light transmittance but low emitting properties (5) Energy-star Appliances (6) LED light Fixtures (7) Tankless water heater - Low-flow Toilets - dual flush system (8) Rain Barrel - to use water for lawn & plants (9) Composter - Today’s composting system

[@silverbemr]

Have you seen or spoke with Hobbs ICF?

[@estor5681]

Fur the wall and hang it from the furring.

[@NukeDoggyDog]

Perfect Block is ideal for a stucco or plaster finish, rather than siding. Are you married to a siding finish? Also, have you considered making your own styrocrete blocks?

[@mikeholman4284]

Are you just talking exterior finish? Is it possible to plaster finish Perfect Block inside the home, rather than drywall? Or is that impractical and going to be problematic? Seems like it would save a lot of expense if you could just coat the inside with plaster. We're going to stucco outside. I was quoted 4k for shipping with Perfect Block but that really doesn't worry me if I can build with it and pour without bracing and worrying that the walls could collapse.

[@justincase2541]

They say perfect block has teeth and you don't need hardy board for stucco

[@matt-justice]

Yep I really wanted to try it until they quoted $5,000 just for shipping. Ordering was also very difficult after multiple phone calls… needless to say, I went with regular ICF blocks.

[@HomesteadOC]

Which is best for a thermal mass type home? How does the 2 sections of insulation work will a bermed house or a walkout basement?

[@matt-justice]

Excellent question. I'm considering this myself for my next build. I went with Fox block for this project, pour was complete back in September... some block manufacturers are just now reaching back out to see if we want help, which is insane. I'm imagining other people are dealing with this too, not sure. Fox block wasn't perfect, had a blowout, had issues with clips coming off using the big pump hose, some blocks separated during the pour, etc... Overall, I'd use them again, but I wouldn't follow the same setup process. Long way to say, I'd use them for a thermal mass home, but one thing to consider is using a concrete uninsulated inner wall for your structural component, then backfill 36" with foam barrier like the newer earthship designs. Haven't tried either yet, still kicking around options. ICF is perfect for walkout basement portions, especially if not backfilled.

[@HomesteadOC]

Thanks for the quick response. After watching the video I wandered around online looking for an answer. What Ive found is that you dont want insulation between the living space and the thermal mass. Outside is fine, but I realized that having an earth contact home insulating between the dirt and the concrete would also not be ideal because it separates your small thermal mass wall from the giant thermal mass of the earth. My ideal now is to make 2 concrete or CMU walls 5’ apart and fill with sand/crushed gravel for drainage and no water/vapor barrier on the outside walls. The roof will cover both walls and any water that gets past the outside wall will drain out before the 2nd wall. You will still keep a large thermal mass of 5’ of fill plus the 8” each side of concrete or CMU. Im really not fond of foam, plastic, offgassing type things in my home. I prefer more natural materials. As for the roof, id really like to have a living roof for asthetic, but being in the southwest I believe collecting rain water is important. Have you done a concrete roof before?

[@matt-justice]

Sounds perfect. Only part that may differ is the walkout portion… it’s relatively unsheltered unless you bring the mass wall all the way around, but this would create a tunnel door? You might still like the performance of ICF for that portion only… No concrete roofs yet!

[@HomesteadOC]

Ive considered doing icf for portions of the house, but was kind of worried about how they would tie in to the uninsulated concrete or cmu. Ive seen lots of tie ins with wood, but i never see anyone do it with different types of concrete, cmu, stone etc.

[@matt-justice]

No issue. Tie in on your rebar runs to both, and pour ICF right up against cmu.

[@SlickNickBA]

My next house will be made entirely from ICF.

[@m.weston7114]

EF Block in Arizona. 10' x 12" x 5' Long. 40 R factor, styrofoam mixed with concrete. Dont mix an ICF block with woof framing, your wasting the whole concept of the foam block concept. Wood houses are not efficient and are old school, they are old technology, that contractors refuse to advance out of.

[@PatrickDNeary]

Have you looked into omni block?

[@keithdygert1120]

What do you like about OB over TPB? Looks like you need an experienced mason for OB whereas TPB is more DIY friendly. Not sure if you need a structural engineer on both? OB has effective thermal mass. Idk if TPB has that or not? OB can also be the finished wall inside and out which could be nice but I don’t think I want that as a finish. Is one stronger than the other? Thanks.

[@pouranh]

🙏🙏🙏

[@LOGDOG5375]

@Matt Justice Have you made your decision yet?

[@matt-justice]

Yep ordered fox block, the perfect people were nuts

[@sammyc1234]

Yea please explain further because I was about to go with Perfect block.

[@sammyc1234]

@@matt-justice.

[@BreezeofBliss]

@bdlc1701 probably poor customer service. Most people who are answering phone don't know or don't care. It's only the commission based sales people, who find it worth their time to make the effort to educate the customer on their products.

[@GeelaneesSoRandom]

Aloha Matt. I just completed my final chemotherapy session a month ago. Im wanting to buy the radiant health two person sauna, and put it in my garage. I have a newly built 2023 home. Will my standard otlets be suffice, or do i need a stronger outlet? I saw that the website said 110 volt outlet would do. I just want to make sure before i purchase. Mahalo