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**Installing basement windows procedure help**

**Installing basement windows procedure help**


Old 08-15-06, 09:10 AM
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Join Date: Aug 2006
Posts: 2
**Installing basement windows procedure help**

Hi, Ive been scouring the net to find a proper procedure how to install basement windows. Can someone tell me whats wrong with my tentative plan and add to it or set me straight?

I have poured concrete rough opening and new construction windows with nailing flange.

1. make a new buck box(i think thats the term) of treated 2x6 (from outside to finished drywall is 1 footish)
*is 2x6 or 2x8 better?
2. use construction adhesive to bond wood to concrete and screw with tapcons.
3.use calk to bond nailing flange to wood buck box.
4.nail a wood trim to the buck box around the window.
*where should the finished window be in relation to the foundation wall? Flush? or recessed(by how much)?*
5. foam the window in place from inside.
6.use plywood to make a new interior box to bring the window to the interior drywall. Does the plywood just butt up to the window and sit on the 2x buck box? or how do you properly bring the interior finishing to the window?

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Old 08-15-06, 03:30 PM
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First, you need to determine where the window will be mounted- whether the nailing flange will be flush with the exterior wall surface, or whether it will be recessed. It's pretty much up to you. Some people think it looks weird to have basement windows sticking out past the wall surface, since basement windows usually don't have siding around them- just the trim. That's a call you'll have to make.

If you will be recessing it, I'd suggest it be 1 7/8" back so that you can cover the nailing flange with a 2x2 which would then need to be clad with aluminum trim coil, or you could use Miritec or something that could be painted. (depending on your masonry size and window size, your trim may not turn out to be the same size on the sides as it is on the top and bottom) After the trim has been clad (or painted) the outside perimeter would be caulked with a polyurethane sealant that sticks well to cement. The inside perimeter of the trim would be sealed to the window.

If you will be installing the window flush with the exterior, then your trim can be symetrical, and can extend out onto the cement wall surface a little.

You pretty much have all the steps right. I would only add that you probably want your wood buck to extend all the way into where the drywall will cover it. (this is so your extension jamb trim will have something to nail to.) If that means using a 2x8, so be it. I've found that it works best to install the top and bottom pieces first and anchor them in place before cutting the sides to fit- you get a tighter fit that way. If the masonry opening is *really* nice, then you might be able to build the box 1/4" smaller, insert it in the opening, shim it in place, then caulk the gap on both sides with PL polyurethane adhesive. But you'll cuss if the opening isn't perfect or you make the box too tight... believe me... get out the sledge hammer! For anchoring, I prefer to use the 1/4" Tapcons because the 3/16" ones strip too easily. You'll probably need 2 3/4" lengths for anchoring your wood buck.

If you have a 2x4 wall inside, then lining the entire masonry opening isn't so critical, since you will be nailing your extension jamb trim to the wood buck near the window and to the 2x4 rough opening near the drywall. Ideally, the 2x4 wall would be framed after the wood buck is installed, and the rough opening in the 2x4 wall would be level and square with your wood buck.

When you go to foam the window, remember that there are very few window and door foams that are meant for vinyl windows. They all overexpand and will bow the windows out- even with some of the ones that say "will not bow frames", you have to be very careful that you use the foam SPARINGLY. I always use DOW *latex* window and door foam for this reason, because it has very low expansion pressure and will NEVER bow a window out, even if you use too much.

As far as trimming the window, you have the right idea with the plywood box. I'd suggest that you install some iron-on edge banding onto the interior side of your plywood jamb before you assemble the box. That way you can maintain a nice 3/16" reveal around the edge when you put on your casing. Also, once the window is installed, you practically never have a uniform wall thickness (drywall to window) at all 4 corners of your opening. To deal with this, you could taper your plywood box to fit, but it's easier to make it one uniform thickness and then cover the gap by adding an additional trim around the perimeter. After the plywood box is shimmed into place and nailed in, I always install a piece of trim (baseshoe, screen moulding, or lattice) on all 4 sides, and push it up tight against the window. Baseshoe looks the nicest, IMO, but if you need to keep it thin, screen moulding or lattice works well.
Old 08-16-06, 06:05 AM
Thread Starter
Join Date: Aug 2006
Posts: 2
Thats exactly what I was looking for, I will giver a try this weekend.
Thank you

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