If trying to get maximum holding power into plastic, like the plastic webs of ICFs. Is predrilling better? Does size matter?

I would say no. A larger screw would displace more plastic and provide better holding. Also, deeper threads would provide more holding power.

Go to your block manufacturers website. Reference their "Fastener withdrawal" test. The test protocol will specify a screw. Use that screw. For best results, choose an ICF with a steel fastening strip.

Go to your block manufacturers website. Reference their "Fastener withdrawal" test. The test protocol will specify a screw. Use that screw. For best results, choose an ICF with a steel fastening strip.

Go to your block manufacturers website. Reference their "Fastener withdrawal" test. The test protocol will specify a screw. Use that screw. For best results, choose an ICF with a steel fastening strip.

Sorry about the triple post. They really need to get a mobile version of this website.

Only Polycrete still uses steel ties. All major ICF companies went to plastic ties years ago to avoid corrosion failure and thermal bridging issues and Polycrete is not approved for Florida or LA for structural reasons. For maximum holding power select a ICF company that uses a 6” plastic tie spacing and use large coarse threaded screws as recommended by company.

https://www.icfmag.com/documents/ICF_COMP_CHART/ICF_Comp_Chart.pdf

Posted By icfbound on 17 Sep 2017 02:45 PM
Only Polycrete still uses steel ties. All major ICF companies went to plastic ties years ago to avoid corrosion failure and thermal bridging issues and Polycrete is not approved for Florida or LA for structural reasons. For maximum holding power select a ICF company that uses a 6” plastic tie spacing and use large coarse threaded screws as recommended by company.

https://www.icfmag.com/documents/ICF_COMP_CHART/ICF_Comp_Chart.pdf

The structure is in the concrete. Don't knock Polycrete, it is a good form. We have used many thousands of sf of Polysteel with good success. And to say that because something doesn't have the blessing of the government is bad is a flawed way of thinking. I do prefer 6" spacing but again have used a lot with 8" and there is little difference. Let's stay on topic.

"The structure is in the concrete. Don't knock Polycrete, it is a good form. We have used many thousands of sf of Polysteel with good success. And to say that because something doesn't have the blessing of the government is bad is a flawed way of thinking. I do prefer 6" spacing but again have used a lot with 8" and there is little difference. Let's stay on topic."

Not Polysteel...Polycrete... Not concrete structure...tie structure... You asked about tie structure. Polycrete tie structure fails from Galvanic Corrosion and the exterior siding departs building in high wind or seismic event. That’s why Polycrete is not approved in Florida or LA. Well documented and try google sometime or just ask building department. If you don’t care I don’t care but someone else could care.

Icfbound, stick to topics you know something about. There has never been a report of a Polycrete structural failure for any reason. Oh, and Polycrete buildings have been rising all over FL since 1988. Facts can be pesky things. Thanks!

Good morning folks, I am a principle of PolycreteUSA. I am new to this as far as posting, however, I follow the post often. I felt the need to jump in here, just so we all understand that ICFbound brain must be bound or at least tied up in knots. There is NO state in the USA that Polycrete cannot be used in, in fact, it is used all over the world. You see Polycrete is the preferred ICF for commercial use. Yes, it cost a bit more than most residential forms. Yes, it has steel ties and a steel fastening strip. Yes, it has a better pull strength than all other ICF. So let's simply put this moronic statement to bed "Polycrete tie structure fails from Galvanic Corrosion and the exterior siding departs building in high wind or seismic event. That’s why Polycrete is not approved in Florida or LA. Well documented and try google sometime or just ask building department. If you don’t care I don’t care but someone else could care."
There is absolutely no thermal bridging with Polycrete. Please, when you have something to say back it up with fact as to show your intelligence. Plus NO reports as far as siding pulling away due to any degrading of the galvanized fastening strip. You see in today's political climate it seem ok to lie and say things that are not fact, but this my friends is the business world be careful what you say and do.
Now let us speak to the cost I brought up, you see, when a stronger form goes up quicker because of its large size and the ability to deliver a precut product, in the end, it cost less because of the shorter labor time and ease of construction. This is why we have been so successful in the commercial world. With the pushback we have been seeing with a few manufacturers because we are quickly becoming the preferred ICF in the residential world due to our pre-cut we understand why the other manufacturers are doing what they are, however, we at Polycrete feel there is plenty of work for all of us and for that reason we do not knock other forms. NO MATTER WHAT FORM IS USED ICF IS THE BEST WAY TO BUILD! You all have a great day and keep up the great work of building with ICF.

We have not used Polycrete, but we have used BuildBlock, Nudura and TF Systems. BuildBlock is a standard 16x48” ICF block system. Nudura is a large 16x96” block system. TF Systems is a vertical ICF system. All have plastic ties, all have worked well and we would certainly agree that ICF is a wonderful way to build.

Frankly, I find this to be a very strange question and post for someone who has used ICF before. One normally follows the product manufacturers recommendation with regard to fastener type and fastener schedule for the required wind exposure category, e.g. Hardie Board ESR-1844 . We frequently install 4x10’ Hardie Board panel on ICF which is quite heavy material. We have never had an issue with any of the ICF that we have used with regard to exterior siding holding capability. In fact, I would say that with 6” or 8” plastic tie spacing, the holding capability far exceeds that of 16” or 24” wood stud spacing. So there isn’t any holding capability issue at all with ICF having plastic ties if you follow manufacturers recommendations and know what you are doing.

I am curious why you would say that “there is absolutely no thermal bridging with Polycrete.” Thermal bridging concerns were the primary reason we have never used Polycrete. If the metal ties are 1 1/2” wide (i.e., like BuildBlock) and spaced 8” (i.e., like Polycrete and Nudura), that would imply that 12.5% of the Polycrete surface has reduced EPS insulation performance than if no ties were present. How much reduced EPS insulation performance where the ties are located would depend on how much reduced EPS insulation thickness covers the ties at the outside surface.

I had never considered galvanic corrosion before with regard ICF metal ties. Galvanic corrosion is certainly real and you wouldn’t want to use fasteners that are a dissimilar metal than the ties, e.g., use aluminum fasteners and steel ties. However, in addition to dissimilar metals, you would also need an electrolyte for galvanic corrosion to occur. Water could serve as an electrolyte, but I wouldn’t expect that to be an issue in typical residential ICF construction. I do know that this was a problem in the past for steel trusses and steel framing studs, but there are ways to deal with it. Anyhow, something new that I hadn’t considered before.

I have not seen pre-drilling addressed anywhere. That is why I ask. Size, at least with BuildBlock's report varies in result on #7 and #8 screws. http://buildblock.com/technical-support/product-testing/

Yes, BuildBlock has very strong points every 8” vertically marked with a “BB” that are good for nearly 500 lbs of pull-out with either #7 or #8. The remainder of tie is only good for about 170 lbs of pull-out...which is more than adequate for most things. We always try to fasten at the BB marks, especially the bracing. We have never felt the need to pre-drill and don’t know why this would be necessary. We do strongly prefer to use screws, but we know of builders who say ring shank nails work fine too.

I am specifically wondering about pre-drilling. I believe pre-drilling helps in some things MgO board, and hurts in others, sheetmetal.

Borst Engineering, the Polycrete steel fastening strip is made from 1.25" x 22 gauge galvanized steel. It's buried 1.25" deep inside the EPS panel and runs horizontally 12" o/c. Some folks who are concerned about a thermal bridge use brick ties with a thermal break.

We have 2 types of starting base. The North American base is a track with sides made from that same 22 gauge galvanized steel. It's shot to the footing and the ICF sits inside the track. This can result in a thermal bridge. If that's an issue for your design, we make a European model in which the track sits inside the ICF block. It works just as well. For added R-value, choose R-Stak, a 16 sqft insert that can be made any thickness you need, from .5" to 18". You might also want to look at Polycrete Big Block Premium made with Neopor from BASF -- 13% higher R-value for 5% more $'s. For more info, feel free to message us offline or through our website. Thanks!

ICFconstruction, normally you only pre-drill material that will crack or split when fastening screws if you didn’t do so. For example, it’s always good to pre-drill wood. I don’t believe that this is a concern for plastic ICF ties. However, I am not an expert on this subject.

BrucePolycrete, I didn’t realize your ties are 1.25” below the EPS surface. That should significantly mitigate the tie thermal bridging. If you then use metal fasteners into the ties, you will create fastener thermal bridging, but the area of the fasteners relative to the wall area is largely insignificant. I believe the BuildBlock ties are maybe only 0.25” below the EPS surface. Of course, being plastic ties, there is much less heat conductivity and thermal bridging potential than metal ties. I will certainly checkout your website and products more...thank you.

I'm wondering why worry about maximum holding force unless you are planning to attach some really heavy stuff to the walls. If 50# holding force is more than enough why care if the maximum is 200#. When I built my house in 2008 I did a test for holding strength of the Build Block reinforced tie sections. I nailed a piece of HardiePlank to a block using something like 10p spiral nails. When I tried pulling the plank off the nail heads pulled right through the plank. I used 8p spiral siding nails to hang the HardiePlank, one in each web. The HardiePlank is 8" to match the vertical spacing of the BB reinforced sections.

In my judgment spiral nails are better than ring shank, and plenty good enough to hang siding on BB forms. The problem with ring shank, as I see it, is when you drive them in the rings get filled with the material the nail is passing through, effectively giving you nothing much better than smooth shank nails. Spiral nails are easier and faster to use than screws, IMO. And if you question the holding power of spiral nails all you need do is look a wood pallet. Every tried to take one of them apart?

I am wondering because I like doing the best I can, not just "good enough". Same reason we build with ICFs.

I appreciate the info on the different nails vs screws. Not so much the bickering on unrelated items. But I am wondering about pre-drilling vs not.

That's good information Dmaceld! We typically use synthetic rain screen behind the Hardie Board panel and always worried about blowing through the panel if we used nails. We do use nails for the Hardie Board battens and trim, and this works well.