double-hung - lower sash alignment

Old 03-03-05, 07:43 AM
Thread Starter
Join Date: Dec 2004
Location: Boston
Posts: 56
Upvotes: 0
Received 0 Upvotes on 0 Posts
double-hung - lower sash alignment

I've got a set of identical double-hung windows installed. On some of them, when you close the lower sash and lock it, the top edge of the lower sash is level with the edge where the lock resides, the full length of the window, so you have a flat a surface.

On some of the others, when you lock them, the top edge of the lower sash is higher than the edge where the lock resides. In most of these cases, the top edge of the lower sash is not level, but typically slants upwards from left to right. The locking mechanism seems to exert pressure on the left side first as it is turned. Also, with most of these windows, it takes a lot more force to lock the window; it offers more resistance. I did use a level to measure all around the window, and they seem to be within tolerance. I guess I will have to go back and measure corner to corner to verify they are square.

Any ideas/suggestions? Could it be a bad locking mechanism? Maybe the sash cords are holding one side up? Faulty install?

Old 03-03-05, 12:29 PM
XSleeper's Avatar
Group Moderator
Join Date: Dec 2004
Posts: 26,416
Received 1,748 Upvotes on 1,572 Posts
The windows are installed out of square. If the sill is perfectly level, you should be able to measure the windows from corner to corner with a tape measure, and the measurements should be exactly the same.

You either need to shim one side of the sill up, or jack the bottom of the window left and the top of the window right, or vice versa.

A good way to double check windows is to bring operate the top and bottom sashes until they are almost closed- then see if the gap underneath the bottom sash, and above the top sash is straight all the way across. If it's not straight, it's out of square, or possibly the sides are bowed.

Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: