Hello to all. 

Been reading this forum for months but have never introduced myself. 
Levigarrett93 from Gettysburg PA.

This is a great forum and I am very fortunate to be able to partake here.

 I am planning an ICF build for myself.  My father has been a contractor for over 30 years and will be participating.  Neither one of us has done an ICF build but think it will be the wave of the future.

I know there are a lot of vetern ICF builders and DIY's and i have a couple questions regarding Wooden Window bucks.


What application would work best considering cost and application.  Vinyl is not an option because of cost.  extra labor is not an issue since its our labor.

Which one would you choose? Why and any suggestions would be great.

1.  Doug fir wooden window buck with a cement barrier wrap or foam roll around wood to prevent contact.

2.  PT wood (concerned it will warp and twist.  all PT moves a lot these days, we feel its to wet and may cause problems)



Also I have attached a picture of what I would like to do.  I plan to recess the windows back from the outside.  The recess will be 3" back from the EPS edge.  The wood will be set inside ICF block and fastened with wind lock fasteners.  Another 2 by will be fastened for my nail flange.  So ultimately all my rough opening will be 1/2" bigger then my window nail flange.  I am certain this has been done but wonder how to cut the sill board (bottom piece of the window buck) and what materials to use to seal the flange to the front of the EPS.  I was planning to use a EPS friendly window membrane.

Please provide any suggestions and comments to help me achieve the recessed window look.  See picture

I am not a big fan of treated wood.  Too many problems with quality of the treated wood.  However, many contractors do use treated wood.  Suggestion:  If you want to use treated wood then look at Timbersil  http://timbersilwood.com/   I think it gets away from a lot of the problems that I have seen in treated wood applications.

Posted By levigarrett93 on 09 Mar 2011 11:36 AM
Another 2 by will be fastened for my nail flange.  So ultimately all my rough opening will be 1/2" bigger then my window nail flange.

Consider removing the flanges from the window and anchoring with (whatever they're called) clips that are used in masonry construction. Andersen Windows has installation details available on their web site. Give careful consideration to water flow. Preventing water intrusion absolutely can be futile, so make sure that whatever water gets past your first barrier has a way to drain down and out and not seep inside the structure. Recessing your windows can make this more challenging, I think. Don't forget to include provision for moisture barrier flashing such as Tyvek FlexWrap. Myself, I would install the windows with the flanges on the outside of the foam simply because I think it will be easier to put them in and get a good water seal. With external mounting you can avoid caulking the bottom edge, both the flange and siding, to allow an escape path for whatever water may get behind the flange.

What kind of siding are you planning on? If it's stucco think about this approach, which I don't recall anyone ever suggesting. Do the stucco finish completely, including wrapping it around and into the window openings. Then install the windows, sans flanges, into the stuccoed opening just like you would do with masonry construction. Caulk between the stucco and window frame will provide the water barrier, and foam insulation will provide the air barrier.

Based on my one experience of building a house 1/2" larger than the window for your rough opening is way too tight. I would recommend 3/8" to 1/2" on each side, and up to 1 1/2" total up and down. But on the other hand if your father has installed many windows then maybe you will be comfortable with a tight fit. However, you're likely to have more vertical variation in your window openings in ICF than in 2x framing, especially since this is your first ICF build.

Have you looked at the threads that were posted here during the past 4 years about window installations? The subject has been discussed quite a bit, especially about 3 to 4 years ago when I was planning and building my house. If you have trouble with the search function come back and I and others can help you locate them.

Than you gentleman.
Dmaceld I already have eldorado stone veneer and either cedar planking or cement planking. I have searched and read a lot and I was afraid that I would have to put the windows towards the out side for ease on install. I have 15 years construction experience and have installed at least 100 windows so I am not afraid by any means just was in a quandary about the best procedure. I will not be able to cut the flange since I am putting in a lot of Casements. Also I have a door going from the master bedroom to back porch and the door will only open about 90 Degrees if installed towards outside.

Depends on type of block you use.  Some have foam bucks that you can use.

Posted By pjf on 09 Mar 2011 03:12 PM
Depends on type of block you use.  Some have foam bucks that you can use.

I have installed windows with both foam bucks and with different wood designs. If given an option I will always use the foam bucks as the wood is very hard to air seal (pulls away from the concrete as it shrinks) and provides thermal bridging. If you do use wood, route a dove tailed groove in the back to help lock it to the concrete. If you go to IntergraSpecs web site you can find a window detail where they screw 1/2" plywood pieces to the window jambs and then screw the plywood to the web in the foam buck. Low expansion foam into the void and you have a solid reasonably tight detail. While you don't screw into the window flange, it is still there as part of the exterior rain shield. Bob

Bob I just looked at the picture your are talking about. I understand but dont want to limit myself to Intergra Spec. I am pretty sure I am going to use Nudura .

You mentioned a dove tail in the wooden buck. Your logic is that the cement will fill the dovetail? Please elaborate.

Thanks

Nudura has an end cap to buck the sides of the window. It looks pretty much exactly like Integra Spec's. I don't see anything on Nudura's site like the Integra Spec header. Perhaps a Nudura expert wil post.

If you go to IntergraSpecs web site you can find a window detail where they screw 1/2" plywood pieces to the window jambs and then screw the plywood to the web in the foam buck.

http://www.integraspec.com/Featured%20Projects/IntegraBucks%20-%20Window%20Installation.pdf

This is the link to what I think you were talking about. Bob you feel confident with that mounting system for casement windows?

When we use wood bucks and go back later, we can see light between the wood and the concrete so therefore air leak. You can put the wood in just the cavity but than you still have to screw/nail the window through the foam. If you use a dove tailed slot in the back of the buck i.e. the length of the buck about mid point or two grooves about 2" apart, the concrete can flow into the groove and make a better seal. Also drive some 5" spikes in a staggered pattern through the buck will help keep the wood from warping as it dries. When using the plywood, I use about 3" wide strips and 3/4" less than overall wall depth. Keep the strip 3/4" away from the nailing flange allows some foam to get between the end of the strip and the flange for a seal and thermal break. I use a couple of blobs of PL Premium construction adhesive and some 1.25" wood screws into the wood jamb of the window. Space the strips about 18" apart and not to far from the corners. This will give you something to tack your jamb extensions to as well giving a nice clean look with even margins. Bob

NUDURA has a variety of options, for this. Your best bet is to contact NUDURA and they will put you in touch with one of their distributors. Below are a couple of links that you can see the end cap and view their product guide:

http://www.nudura.com/en/divisions/contractors_builders/icf-prooducts.aspx (scroll down to the bottom of the page and you will see some of their products.

http://www.nudura.com/en/Technical_Centre.aspx (this link will take you to their tech centre where you can download their product guide)

Rook

My suggestion would be to build an aluminum sill pan out of coil stock, that is sized to allow the windows to set at whatever depth you wish.