old timber window frame in stone wall

[Haldeman1773 (WavyGlass)]

So, the headers of my old window frames have tenons that extend back inside the stone wall. Very common, according to everything I read.

I can cut them out with little trouble, but the only way to fit the replacement components back into the wall (if they are to made the same as the original), is to pull some stones which appear to be supporting other stones. I am a bit nervous about doing this, and have it unravel more than I intend.

Advice? Yes, I could make the new frame without the wings, and find some other way to attach it to the wall, but I do like to make all my repairs on old houses match the original work (when it was done well).

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[Don M]

I would be leary of disturbing those stones; I have the same issue with an old wooden header in the stone wall in my celler. I wonder if you could design your new header with the wings separate from the header so they could be slipped into the pockets in the stone then put the header in place in a way that would allow pinning of the wings to the header creating a solid more original piece? Actually it might only take one wing to be pinned as the othe could be part of the header & slid into the pocket on one side then pin the other using a dowel like the pins used in a mortice & tennon joint seen in timber frame construction.

[shazapple]

If I understand correctly, you build something similar to a 3-ply beam, but the middle pieces of the beam would be longer in order to act as the tenons. The centre ply could be cut in half in order to fit it into place, then the outer plies nailed on. The outer plies should make it almost as strong as a solid beam.

[Don M]

Yes, that's what I had in mind. It can be modified to exactly match the original header which may have several variations depending on the original builder.

[Haldeman1773 (WavyGlass)]

A decent retrofit, no doubt. However, I get off on the thought that some day 200 years from now, someone is going to pull my new but perfect 1770's replica frame out of this wall, have it carbon dated to 2013, and then start a whole new level of debate among old house-philes, about the age of this house and when exactly people were building timber framed windows.

[Haldeman1773 (WavyGlass)]

Well, I just couldn't leave well enough alone. Started chipping mortar around those stones, and the stone above the header on the right just crumbled. Looks like the coarse above moved a bit, as well. Called my mason to get his eyes on it before I proceed.

Old header is rotten, so it's gotta come out one way or another. Perhaps I need to pick up one of those Fein multi-tools, so I can use the door jamb saw to just plunge it out. No easy way to get at that header.

Then the big question becomes how to fasten the new frame into the wall. I've read a few accounts of using threaded anchors, or drilling and bedding all-thread in epoxy. Given how fragile some of the stones are, I'm not in love with any idea that involves a hammer drill.

[HB2]

For future work like this, get yourself a piece of steel angle, 2 x 3 inch should do, and a few inches wider than the window opening.

Use a grinder or hand tools to remove enough mortar across th top edge of the frame to slip that angle in to the wall. Then put a post from the bottom window sill to the center of the angle iron to support the header stones while the window header is removed. With the angle iron extending past the opening, it should hold everything in place when you remove the original wood header.
When you slip the new header back in place, pack the pockets in the stone with a little LIME MORTAR. (Be sure to soak the ends of your new header so it doesn;t suck the water out of the mortar) this will ensure that the new header is bedded firmly in place. The frame of the window can be attched to this new header, eliminating most of the need to attach it to the stones along the edge of the opening.

I like riven white oak for new window headers and nailing blocks in the stone wall. It matches what they originally used on my house.

Good Luck.

HB

BTW I have the fein and it's awesome. I don;t use it often, but when you get in these situations, it's the only tool that will work. Lucky for you, now the patnet has run out on it and several other manufactureres make similar units.

[Haldeman1773 (WavyGlass)]

Oh, yes! That was quite a few projects ago.

Let's see if I can dig up some photos...

Okay, here we go:

I made a mock-up in doug fir, with the full "wings" treatment, planning to remove the stonework from the wall to set the window, and rebuild around it:

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[Haldeman1773 (WavyGlass)]

Then I bought some KD oak timber (not cheap!), and milled out the final parts:

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[Haldeman1773 (WavyGlass)]

Mortised, tenoned, and assembled, again with full wing treatment:

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