View Full Version : How to replace old steel frame windows in concrete block walls?

Stephen Tashiro
10-04-2012, 1:49 PM
What's a good link (or book) that shows how to replace old steel frame windows in a concrete block wall?

The links I found on Youtube show how to replace modern windows where you can detach the window from the casing that has the flange. Those directions don't apply to old steel frame windows. The frames of these windows have a flange that is an integral part of the frame and this flange is set into the concrete block with mortar. You can't detach the window from the flange. I understand to tear out the old window along with the flange, (This is a destructive process! The frame and flange are about the same gauge as typical angle iron. They don't come out of the masonry easily.)

How should the replacment window be installed? I once watched the process from a distance as this was done on a house across the street. It appeared that the carpenter made a frame of 4 boards that snugly fit the masonry opening. He then installed the new window in this framework. I'd like to see plans that show all the details of that type of work. One consideration is that you've already lost some of the opening by putting the framework of boards in. What's the best design to preserve the part that's left?

Ken Fitzgerald
10-04-2012, 4:26 PM

We replaced the one in our basement bedroom by removing the frame, flange and window. Then simply caulked the new one in place. It's last 29 years since it was done without any problems.

Lee Schierer
10-04-2012, 5:16 PM
I replaced the steel framed windows in a house with glass blocks. They let in the light, keep out the cold and burglars. You can cut the top and bottom frames with a cut off wheel in a hand grinder.

Kevin Bourque
10-04-2012, 5:25 PM
I've done this a million times.
I take the window out of the frame, then I take a sawzall and cut the frame as far as I can.
Then I take a pry bar and pry it out of the concrete. Once I cut the frame all the way through I pull the rest out by hand or with a hammer.
They actually come out pretty easily once you get that first cut all the way through.

After you get this done you can take 4 boards and make a frame to set the new window in.
I glue them to the concrete and then fill any gaps with expanding foam sealant. You could also use masonry nails or other fasteners.
Or you could forget the wood frame completely and just get some Tapcon screws and screw the new window directly into the concrete.
It really depends on the window jamb.

Stephen Tashiro
10-04-2012, 5:48 PM
I more or less understand how to remove the old window and put the 4 boards in. I don't understand details, like how to do the flashing or trim. I don't understand what the options are for a window sill on the interior side. For example, would the bottom board of the 4 boards form the inside window sill? I don't know whether to use a window with a flange and have the flange go over the 4 boads or whether to get a "replacement window" that has no flange.

Dave Lehnert
10-04-2012, 6:20 PM
I had new windows installed by a national company in a brick home. They took a crowbar and popped the old steel window frame right out. When they set the new windows, they used drywall screws, through the new window frame, into the brick mortar to tack in place. They used a special caulk that the installer said glued and held them in place. Been installed for over 10 years without problem.

Stephen Tashiro
10-05-2012, 3:54 PM
But the details, the details! Everyone wants to talk about taking out the old window and putting in a new frame. What I need a link that shows things like trim, interior sill, flashing!

Myk Rian
10-05-2012, 4:09 PM
But the details, the details! Everyone wants to talk about taking out the old window and putting in a new frame. What I need a link that shows things like trim, interior sill, flashing!
Ever use Google to search for info?
Try this from "This old house".

Stephen Tashiro
10-05-2012, 9:08 PM
Try this from "This old house".

That's interesting, but it looks like he's nailing some of the trim in the wall where a concrete block wall would be concrete.
(What kind of air-less nail gun is that?)

Ken Fitzgerald
10-05-2012, 9:22 PM
Stephen.....Paslode makes cord/hose free nail guns.....and there are electric ones..... http://www.amazon.com/s/?ie=UTF8&keywords=battery+nailer&tag=googhydr-20&index=tools&hvadid=8045095164&hvpos=1t1&hvexid=&hvnetw=g&hvrand=176655749765652744&hvpone=&hvptwo=&hvqmt=b&ref=pd_sl_6vpkpct52s_b