I will be constructing a 2400 square foot ranch and a 40' x 60' barn in a few months. The exterior of both will be nova brik. I am concerned about the weight of the brick being supported by screws only. The installation procedure can be seen at link.
I have used several different icf's in the past and have never had a problem due to tie failure, but there has never been a sustained load on the fastener such as novabrik. I believe the novabrik weighs about 27 psf. If I worked the numbers correctly, each screw would be supporting about 30 lbs. Most Icf's have published values for shear and withdraw (pullout), but I believe the shear value would be of sigificance in this case.  I believe most ICF mfgrs have fastener capacities of around 50-100 lbs in shear depending on the screw used.  I have thought about using the icf I normally use, attaching the furring stips to the tie, then running long (atleast 5") screws thru the furring strips before the pour.  I also thouht about using simpson ledger connectors as well, but I would have a about 2000.00 in the connectors. I just noticed an ICF called buildblock which has a thickened web. If a fastener is installed in a specified area of the web, significantly higher values are achieved. For those of you who have used buildblock, is this web really that much stronger? I would like to think of a way to install the novabrik without installing the furring before the pour as mentioned above, or without using the simpson ledger connectors. However, I don't think I could sleep at night knowing the brick was supported by just the plastic ties. I would be concerned about the brick settling, not necessarily right away, but over time due to the sustained load of the brick and repeated heating and cooling. I would like to hear what other Installers think about this situation.

Thank you very much!!

Bunt

For what it's worth I've attached an ICF product comparison chart I found several months ago. Don't remember where I got it and can't Google it up now.

I'm getting ready to build a ranch style house using BuildBlock forms. There is an extra reinforced area in the web in line with the cross tie. It's about 1" high and 1 1/2" wide. I plan to drive RS nails into them to hang Hardiplank. They are spaced every 8" vertically and the webs are spaced on 6" centers.

I've attached a photo to show what the reinforcement looks like. Ignore the holes. Those are where I drove test screws. You will see a 12d HDG RS nail in the web. I drove it in there to get an idea of how well the reinforced area holds a nail. I haven't been able to pull it out! Mostly because I haven't fixed up a jig or whatever to hold the web piece really solid while I pull on the nail. I put it in a vise but the web piece wouldn't stay in the vise when I pulled on the nail!

Thanks for the picture and chart!!. I wonder if the values shown for buildblock are in the standard part of the web, or the "sweet spot" of the web? Arrx has some impressive values as well. I believe the actual published values for code need to reduced for safety factor of 3 I believe.

Thks!

I was thinking some more about the BB and Novabrick. There are 12 reinforcements on each side of a 16" x 48" form, which is 5.33 sq ft. The brick load would be 5.33 x 27 = 144 lbs per form. If you put a furring strip over every web and fasten it to every reinforcement your load per fastener would be 144/12 = 12 lbs. Pretty low I would think. But plastic is plastic (no pun intended), so there probably can be no guarantee that some minute settling wouldn't take place over many years.

I'd be leery of putting the furring strips on before the pour because of how the blocks can settle during the pour from the weight of the concrete. The ICF builder who I'm working with said walls can tilt during the pour if the braces are solidly fastened to the webs, i.e. the screws are at the bottom of the slots so have no room to move down. The braced side doesn't settle and the other side does. He did say BuildBlock settles less than the Logix he had been using.

Actually according to the icf manual, the furring strips are every 16" o.c. and are screwed every 10" o.c. vertically. With that said, one screw would carry an area of brick 10" tall x 16" wide. This equals 160sq in, or 1.111 sq ft. So the total load for the screw would be 1.111sq ft x 27 psf=30lb/screw. If I used build block the webs are 6" o.c., so I would probably put the furring strips 12" o.c. which would reduce the load/screw a bit as well.

thks again!

Buntly,

I have myself installed novabrik on my Icf house, 2 wall of 32' x 18' plus a back wall of 53' x 18'... To eliminate the same fear I had, I installed 2" fering <---(?) all around the house at 16" intervall that I stapled on with 2.5" staples to distribute the load...Anyway you will need them for the corners because without it nothing holds... Look at my past post for photo and feel freeto ask questions.. Btw Novabrick is a great product with very low waste....My waste was less that 1% ( a big box of 2'x2'x'2) including human errors lollll

The system i used at that time was blue Maxx ( now arxx ) but will be definitly be using Fox Blocks next march. After testing  by getting a sample straight and 90degree from major players I have found that price and reinforcement in that perticular block are great. And the 1.5"x3/8" latts are very strong.

http://www.greenbuildingtalk.com/Forums/tabid/53/view/topic/forumid/4/postid/26732/Default.aspx

Francis

Ps: Don't forget that the starter strip is screwed on plus the first 4 course of brick! then only the 4th, 8th 12th 16th ...... Plus with the furring space I was able to add electrical outside from basement to roof by using the 3/4" space ... :)

Francis, thanks for the info. Correct me if I' wrong, but you used staples to fasten the furring to the ties? Also what was the reason for the typar? I noticed in the bottom picture that you needed to bring grade up yet. Did you bring the grade right to the bottom course? If so are there any issues with frost heave under the brick? (not sure where you are located)

Thks again!
Larry

All,

If you would like a current ICF comparison chart, you can purchase a comprehensive one from ICF Builder Magazine at LINK, or wait until their annual chart comes out in the magazine in a week or so.