There is a good article about window bucks from ICF Mag:  WINDOW BUCKS  From my research, the best window buck out there is the Gorilla Buck 

Has anyone used them and what is the pricing like?

The costing in the article appears to be off by a lot

Wood is by far the cheapest product to use and most user friendly. I can do my version of wood buck for under $1.50 per l/f.

Gorilla Buck was in the $5 ft. Range last time I looked, V-Buck was the same by the time you added in all their bits and pieces.

EPS with wood face is again $3 plus and if you using a nail fin type window it's not ideal to use.

Each require a similar amount/type of temporary shoring so that is a non issue.

Some of the products we see being introduced for the ICF industry are trying to solve or help with problems that don't exist. And by adding the cost can put ICF costs too high having more people question the value of what we do.

Posted By Chris Johnson on 17 Feb 2013 03:11 PM
The costing in the article appears to be off by a lot

Wood is by far the cheapest product to use and most user friendly. I can do my version of wood buck for under $1.50 per l/f.

Gorilla Buck was in the $5 ft. Range last time I looked, V-Buck was the same by the time you added in all their bits and pieces.

EPS with wood face is again $3 plus and if you using a nail fin type window it's not ideal to use.

Each require a similar amount/type of temporary shoring so that is a non issue.

Some of the products we see being introduced for the ICF industry are trying to solve or help with problems that don't exist. And by adding the cost can put ICF costs too high having more people question the value of what we do.

Recently all the big ICF companies got together and conducted laboratory tests on window bucks to see how they performed in air sealing. From what the initial reports show, the wood window buck install method showed to be pretty horrendous in window sealing and that was the greatest area of leakage. In addition, Green Building Advisor professionals also did similar research and testing through blower door tests on real ICF homes and it showed that the typical wooden buck window and door install method proved to be a gaping hole in ICF air leakage. The top plate to roof connection area was another leak spot on ICF homes.

So I do believe that a problem exists and there is data to show that the problem is real. Apparently the ICF industry also believes a problem exists, albeit minor but still an issue that needs to be addressed.

There already have been real life cases where termites tunneled through the EPS so that they can munch on the wood window bucks. Modern day treated wood will do everything but remain straight and true. It splits, twists, cups, warps and even after all that, it is unseen because it is hidden behind the finishing materials.

John Semmelhack worked on an ICF Passihaus in Wisconsin. The October 2010 article on GBA stated:
“What was found that didn't work as well as an air barrier was the spray foam between the window casings and the ICF wall. Not only does a bead of spray foam between window and framing make an ineffective air seal, it's probably a lousy water seal as well. He suspects many leaks found in window installations on the Maine coast might rightfully be attributed to that. "

Non-treated high grade wood with a capillary break would work better than pressure treated wood, right?


 

Look back through some old threads and I posted how I build wood bucks (it's probably 2-3 years back).

Without statistics but from personal knowledge and observation, 90% of window installs are the problem, not the buck itself. If you properly flash your buck, install your window, counter flash that and spray foam you've done the job right. Too many times I see windows without proper flashing, poor caulking after facade completed, etc. etc. that creates your issue.

Modern day treated wood will do everything but remain straight and true. It splits, twists, cups, warps and even after all that, it is unseen because it is hidden behind the finishing materials.

My treated wood bucks had some pretty substantial cups after we poured the walls. A few months later, everything was dry and straight again.

We cut all the openings in the formwall a hair on the shy side (meaning took a little more foam than necessary). About a sawblade width. This helped facilitate squaring up the openings rather than fighting high spots here and there. After the walls were poured, all the cracks around the edges got foamed with Great Stuff. It was pretty easy to push the can nozzle into the crack and if there was any separation between the concrete and the wood buck, I'll bet it got foam filled, too. I've been over my openings a dozen times and there never was much air coming from between the buck and the wall. After the foam sealing treatment I described, I never remember any at all.

One of the guys must have been dyslexic or something because he kept cutting his openings an inch less on all sides. Consequently, in a few locations, we had concrete squeeze out to the interior and exterior edges of the buck. The treatment there was to insert a rotohammer bullpoint and chisel the concrete overflow back to the wall depth. Imagine jamming a jackhammer in there and beating it back. Even those bucks were stuck fast to the concrete wall because of the ringshank anchors.

My vote is still for treated wood bucks.

Posted By ICFHybrid on 17 Feb 2013 10:24 PM

My treated wood bucks had some pretty substantial cups after we poured the walls. A few months later, everything was dry and straight again.

My vote is still for treated wood bucks.

The treated lumber out here in my neck of the woods is garbage lumber. They take the crappiest piece of lumber (3 common) and then soak it in the chemical, they remove them and they then do the twist and splits as they dry out. When a board cups and bows, it develops cracks and splits, even when it is forced back into position.

What happens to a window frame when a buck bows and cups and presses against the frame of a window as it does the giggle dance?

Wouldn't it be better to install a hardwood (first & seconds or select quality), install a break between the wood and concrete, and then have a much more stable and strong product? Even a quality C or D in a softwood is still better than treated lumber.

What are we taking about here price wise, a couple of dollars more for quality lumber?

Take a 2x6, rip it in 1/2 on a 45 degree angle, next rip 3/4" ply to the width of the block, built the pieces to create the buck, twisting and warping of the 2x is near next to nothing as the pieces are pretty small now.

3/4" plywood

==================
I____\. . . . . . . . ./_____I


Ripped 2x6


Hopefully that makes sense.


Couple of options, when building the footing, use 2x6, when done, strip it and use that. or order 2x6 and have the lumber yard rip it for you, they will also rip the plywood for you as well, cost is minimal

If your PT is garbage as you described, use regular wood (OBC allows regular wood 6" above grade in contact with concrete) and if needed, spray your own PT chemical on it to satisfy USA building code, it's legal.

The problem with your hardwood idea is everything will need to be predrilled prior to nailing/screwing your windows in, drywall, trim, etc. Good way to upset sub trades.

What happens to a window frame when a buck bows and cups and presses against the frame of a window as it does the giggle dance?

It was dry and straight by the time the windows went in.

What are we taking about here price wise, a couple of dollars more for quality lumber?

I get quality treated from the lumberyard by ordering it.

Posted By Lbear on 17 Feb 2013 10:50 PM

What happens to a window frame when a buck bows and cups and presses against the frame of a window as it does the giggle dance?

Won't happen. The rough opening for the window, i.e. the inside open area of the buck, is about 1/2" all around larger than the window frame. That's the gap that has to be filled in with sealant to keep the assembly air tight.

My windows don't leak air. The top and side flanges are silicone sealed to the foam and all four sides have foam filling the gap between the window and buck. The bucks have sill seal foam on the concrete side. And then there's the outside window trim and siding and peel and stick over the flanges, and the interior trim tight against the window frame and drywall.

I think your concerns about leakage around wood bucks is like swatting at holographic flies!

Posted By dmaceld on 18 Feb 2013 02:56 AM

Won't happen. The rough opening for the window, i.e. the inside open area of the buck, is about 1/2" all around larger than the window frame. That's the gap that has to be filled in with sealant to keep the assembly air tight.

My windows don't leak air. The top and side flanges are silicone sealed to the foam and all four sides have foam filling the gap between the window and buck. The bucks have sill seal foam on the concrete side. And then there's the outside window trim and siding and peel and stick over the flanges, and the interior trim tight against the window frame and drywall.

I think your concerns about leakage around wood bucks is like swatting at holographic flies!

What to make of the ICF manufacturer study which shows that they do leak and from the GBA article in which experts said the same? I'm just going by what the experts are saying. 

John Semmelhack worked on an ICF Passivhaus in Wisconsin. The October 2010 article on GBA stated:
“What was found that didn't work as well as an air barrier was the spray foam between the window casings and the ICF wall. Not only does a bead of spray foam between window and framing make an ineffective air seal, it's probably a lousy water seal as well. He suspects many leaks found in window installations on the Maine coast might rightfully be attributed to that. "

Lbear, the experts are not in the field doing this daily, they are making simulated models with various scenarios. There is also a biased being done during these tests.

Each of the window bucks being tested and promoted can perform well, provided the installer does a good job and takes all factors into consideration during installation to prevent air leakage from happening, this will include flashing and sealing.

At the end of the day even with the best installation techniques the window itself has to be of good quality. A casement window will lock and seal much better then a slider, so no matter how good the bucks are and the installation itself is good but an average slider is creating a 'big hole' in the wall.

Another option is to use windows that don't require a buck. I didn't use window bucks, the windows are directly attached to the concrete with screws.

http://www.rekord-fenster.com/public/files/pdf/rekord-anleitung-neubau.pdf

Posted By galore on 18 Feb 2013 03:51 PM
Another option is to use windows that don't require a buck. I didn't use window bucks, the windows are directly attached to the concrete with screws.

http://www.rekord-fenster.com/public/files/pdf/rekord-anleitung-neubau.pdf

Got this in English?

And where did you get the windows?

I have heard feedback from contractors on non-wood bucks. The general feedback as been quite negative. THey cost more to buy and take more time. Perfectly straight and non wood (rot) is about the only pros they have with it.

I used treated wood for the sill, (2x6 ripped in half to pour the sill below the window) and then non-treated 2x10s for the remaining 3 sides. I wrapped the 3 sides with tyvek I ripped the width of the framing. Didnt have a single issue with bucks twisting or moving. I am using 4" wide flashing tape on the exterior to overlap the nail flange, buck, and onto the ICF foam. Obviously this does not help the sill location since its not supposed to be taped. However with the flexwrap sill flashing lapped over the buck and around onto the foam (and the window foamed to the flex wrap), that should seal that joint pretty well. My first blower door test will be in a couple weeks on my ICF house, so I will see how much my wood bucks leak.......

Posted By lzerarc on 18 Feb 2013 11:28 PM
I have heard feedback from contractors on non-wood bucks. The general feedback as been quite negative. THey cost more to buy and take more time. Perfectly straight and non wood (rot) is about the only pros they have with it.

I used treated wood for the sill, (2x6 ripped in half to pour the sill below the window) and then non-treated 2x10s for the remaining 3 sides. I wrapped the 3 sides with tyvek I ripped the width of the framing. Didnt have a single issue with bucks twisting or moving. I am using 4" wide flashing tape on the exterior to overlap the nail flange, buck, and onto the ICF foam. Obviously this does not help the sill location since its not supposed to be taped. However with the flexwrap sill flashing lapped over the buck and around onto the foam (and the window foamed to the flex wrap), that should seal that joint pretty well. My first blower door test will be in a couple weeks on my ICF house, so I will see how much my wood bucks leak.......

You can use incense sticks or fog sticks to locate air leaks around windows & doors on the inside.

Did you install your windows as outie or innie?

The IRC code also allows for naturally resistant lumber like redwood or cedar, both very nice to work with

Posted By Lbear on 19 Feb 2013 03:17 AM

Posted By lzerarc on 18 Feb 2013 11:28 PM
I have heard feedback from contractors on non-wood bucks. The general feedback as been quite negative. THey cost more to buy and take more time. Perfectly straight and non wood (rot) is about the only pros they have with it.

I used treated wood for the sill, (2x6 ripped in half to pour the sill below the window) and then non-treated 2x10s for the remaining 3 sides. I wrapped the 3 sides with tyvek I ripped the width of the framing. Didnt have a single issue with bucks twisting or moving. I am using 4" wide flashing tape on the exterior to overlap the nail flange, buck, and onto the ICF foam. Obviously this does not help the sill location since its not supposed to be taped. However with the flexwrap sill flashing lapped over the buck and around onto the foam (and the window foamed to the flex wrap), that should seal that joint pretty well. My first blower door test will be in a couple weeks on my ICF house, so I will see how much my wood bucks leak.......

You can use incense sticks or fog sticks to locate air leaks around windows & doors on the inside.

Did you install your windows as outie or innie?

outie. I like it better for various reasons.

I always put my bucks inside of the form, less bracing needed and no air leakage

Gentlemen;

Lbear is correct about the testing series undertaken by many of the major ICF companies, in cooperation with the BC Homeowners Protection Office. I built the modules, and witnessed the testing done at a window manufacturing facility in BC on a multi-million $$ testing frame. There have been two series of tests done over the last two years, the second done using lessons learned from the first. A final report on this testing is due out in September 2013 from an international engineering firm who ran the testing.

We learned a lot of lessons from this, not the least of which is that ICF walls with windows can be constructed to be 100% air and water tight when subjected to wind-driven rain, even up to levels that don't exist in nature. (Yes, we tried it......)

We also learned that wood bucks can be quite problematic, especially when spanning the entire cross-section of the wall. (full-width wood bucks) On balance, this was pivotal research in the history of ICFs, and will pave the way for some reliable "
best practice" detials that will be shared across the industry.

I will be posting the results when released in September.

d'techguy

Posted By d'techguy on 30 Jul 2013 08:31 PM
Gentlemen;

Lbear is correct about the testing series undertaken by many of the major ICF companies, in cooperation with the BC Homeowners Protection Office. I built the modules, and witnessed the testing done at a window manufacturing facility in BC on a multi-million $$ testing frame. There have been two series of tests done over the last two years, the second done using lessons learned from the first. A final report on this testing is due out in September 2013 from an international engineering firm who ran the testing.

We also learned that wood bucks can be quite problematic, especially when spanning the entire cross-section of the wall. (full-width wood bucks) On balance, this was pivotal research in the history of ICFs, and will pave the way for some reliable "
best practice" detials that will be shared across the industry.

I will be posting the results when released in September.

d'techguy

Please keep up informed and let us know where one can find the test results when they do come out.

There was quite a bit of talk on GBA about treated wood bucks for windows and spray foam. Mainly on how it does not do a good job of sealing around windows in the long term. I really like the Fox Buck which eliminates the wood bucks and I believe from studies I have read that it is a better system than wood and spray foam.

I would be curious to see air leakage tests done on ICF homes using treated wood bucks after 5 or 10 years to see how well the air seals around the bucks are doing.

These studies are a long time coming and from the sounds of it they will really be an eye opener to the industry.