Framing windows

At the windows now at my cabin. Using 2x7 to box in the windows. What is the method of securing the boxes in? Iam leaving 1” space above box for schrinkage . Iam using vinyl windows so i still have to make a finish box that fits into the groove in the vinyl.

If I understand you correctly...

I believe, from what a buddy who built a log home has told me, slotted holes for the fasteners in the side frames to allow movement The windows will still move down, but the frames will remain intact. From the shrinkage he showed me, 1" may not be enough vertical clearance. Or it may. Depends on the how many logs the vertical height of the windows span and their moisture content to start with.

There is probably a more traditional way. The above uses screws.


Regards,
Rufus

I am not sure I have enough information to make a suggestion.

Is the cabin a log cabin, or timber frame?

If it is a log cabin then I am not sure 1 inch is enough space. Even if you have (8) logs 12" thick, you could only get 1/8 of an inch of shrinkage in each log before the window breaks. I would think you would get more shrinkage  than that.

Normally, the window is secured to a frame, and then the frame is secured only to the bottom, with the sides fitting in a channel made out of framing lumber so that as the wall shrinks, it settles downward, without moving the frame.

Hi Yve!

I found a short (1:45) animation on youtube that shows how to do a window buck in a log home that allows the logs to settle and move and not rack a window which could result in sticking or inoperable window sashes. In the video, they show using steel angle iron to fit in the vertical channel cut into the log ends in a window rough opening. The window bucks in my log home are done on this same principle, but are all wood. Pieces of 2x8 were ripped on a table saw making some two inch wide pieces, which were then nailed to the center of the 2x8's, making a T and these made up the two vertical members of the window buck, allowing the logs to expand/contract and slide down for settling. The top and bottom pieces of the window buck are fastened to the two vertical pieces, making an independent opening for a window to fit into. Only the bottom piece of 2x8 in my window bucks are fastened to the log below it, the two side pieces merely sit there held in place by a friction fit, and the top 2x8 is nailed to the two verticals. I hope all this makes sense and you're able to paint a picture in your mind of all this. Here's the short video.

James, what you have is what I tried to describe, but I really like the idea of the steel angle iron as well.

Nice video!

James's video shows the right way - great educational piece, that.  I misremembered and my friend set me right this morning.  

The slot can alternatively be sized to accept a wood slider, say 1-1/2" square, instead of the steel. According to my friend who's been in his home for 5 years or so, the logs can shrink 1/4" log or more depending on their size. So more room at the top can be better.

Regards,
Rufus

This is for a log cabin.8” x 6.5” high. Flattened on top and bottom. I test fitted the window boxes yesterday leaving 1” space above them but didn’t put any groove or spline in. Probably going to go that today. Got boxes all screwed together, can just take out , cut groove, place spline put box back in and then screw spline to box.Thanks guys for the input..much appreciated

1" [clearance above]

I was told 1/4"+ a log shrinkage. Counting from the bottom of the window up to the log spanning the window opening. Work out?


Rufus