Structural & Functional Window Restoration
We Make Your Windows Function as Close as Possible to New!
“The larger windows included a large sunroom with windows that literally disappear into the wall when raised. Oak Brothers did a fantastic job of getting the windows to work & look almost new again.”
– Jean Jorgenson, Glencoe Illinois
Our 10-Step Process for Restoring
Window Operability
A properly restored window will open with ease, shut securely, seal tightly, and have both an actual and felt sense of solidity! To achieve such a state, all the parts must be structurally sound and function with the proverbial ease of a “well-oiled machine.” We achieve this level of solidity and ease of operation by employing the following ten sets of procedures.
1. We Deglaze the Glass and Remove the Paint
Paint is the single greatest contributor to original windows not functioning well. Excessive paint build-up, paint that has been applied where it was never meant to be applied, and paint that has sealed the sashes shut–all of these problems contribute to disfunction. Finally, paint hides deeper, structural problems. The first task, then, is to remove the glass from the frame, strip everything down to bare wood and bare metal, then sand the frames and refurbish the metal (sash locks, lifts, pulleys, etc…).
But it isn’t just paint on sashes that hinders window operation! Go here to learn about the importance of restoring not just the sashes and movable parts, but the jambs, sills, stops, and parting beads as well.
Many parts of the window opening-such as the pulleys and chain-never should have been painted in the first place! The good news, though, is that once the excess paint has been removed and the parts made functional, the pulleys can be refurbished to near mint condition. Sash cord and chain is best replaced rather than restored.
As one client described how his windows function after we restored them, “the sashes glide up and down like silk and fit snugly.”
(Dan Raeburn, Hyde Park)
Thick layers of paint obscure the sharp lines of molding profiles and turn finely detailed hardware into a blob.
As important as it is to remove it, layers of dirty, cracking, peeling paint makes windows appear in worse condition than they are. We are continually amazed to discover what good structural condition original windows often have, once the paint has been removed.
2. We Harden Soft Wood
As the bottom of this door reveals, wood that is exposed to moisture eventually rots. Oftentimes, though, the rot is only surface deep. When there is solid wood beneath this soft, “punky” wood, we excavate as much of the degraded wood as can be scraped out with modest pressure.
We then saturate the remaining solid, but still soft wood with a hardening agent. The hardener soaks into the wood, functioning like glue that rehardens the fibers. When it dries, we fill the remaining cavity with marine-grade paste epoxy to restore structural integrity.
When used together, wood hardener and paste epoxy enable us to restore wood that would otherwise need to be replaced. Such economy of replacement is consistent with the preservation and restoration guideline that as much original materials that can be, should be preserved.
This is an especially useful procedure in instances such as this door because the surface is solid. It is only the core that is rotted. It is the best of all possible worlds when we can restores structural integrity while simultaneously preserving aesthetic integrity!
3. Replace Missing Wood with Paste Epoxy and Sculpt it to Fit the Profile.
Paste epoxy is useful for replacing missing wood where strength is not a primary issue. We have a variety of paste epoxy mixes on hand (one of which is even harder than wood itself!) depending on how much stress the repaired area must endure. (We never use Bondo because it lacks the strength required for wood-fill)
4. We Implant Scarf Repairs When More Structural Stability is Needed
Sometimes nothing will hold up to the stress that must be endured besides wood itself. Another consideration, as in this scarf repair of a door stile, is whether or not the element will receive a natural or stained finish. In this case, wood of the same species is needed. And, as much as possible, we match the grain lines. Then, when we stain it, we pre-patinate the new wood before staining it so it matches the appearance of the aged wood. As I’ve said elsewhere, our commitment is to enabling the integration of structural/functional with aesthetic restoration.
Both these considerations came into play when we determined how to repair this damaged door stile. We made a scarf repair using the same species of wood as the original member.
Here’s a window sash which has been repaired with a combination of epoxy and scarf repairs. PS – Want to know a trade secret? Sometimes we help along the integration of vein lines by painting them in. There’s a long tradition of imitating paint this way. It’s called Faux Bois. You’d be surprised how many elegant doors you’ve seen in museums and palaces aren’t, in fact, wood at all. The wood grain has been masterfully “faked” using paint.
5. We Replace Stiles & Rails That Have Degraded Beyond Repair.
While we’re picturing this repair on a door, the same procedures apply to windows. Sometimes a stile or rail is too heavily rotted to be repaired. At other times, one or the other piece needs to be replaced because it has warped. The bottom rails of the top sash for wide windows (50″ or wider) often warp beneath the weight of the glass and need to be replaced.
6. Stabilize or Re-build Mortise-And-Tenon Joints and Muntins
One-hundred-year-old sashes are typically joined together by mortise-and–tenon joints. These joints frequently need to be tightened with shims, repaired, or replaced.
A squirrel had gotten trapped inside this vintage Arts and Crafts residence while the homeowners were away on vacation. In desperate attempts to escape, it chewed through most of the bottom muntins in these dramatic casement windows. We had to mill, replace and blend the patina of new wood to restore these windows to their original condition.
7. We Refurbish Pulleys & Re-install Them With New Sash Rope or Chain.
Double-hung windows cannot operate without functional pulleys and chains. 98% of the time, original pulleys can be refurbished, oiled, and reinstalled. But this window is typical of what we find–both the pulley and the chain are smothered in paint. Refurbish the pulleys and replace the chain and suddenly the sashes become operable (and aesthetically pleasing
Then there’s the premium solution. As pictured here, install new ball-bearing packed pulleys and high quality, pure bronze sash chain and you’ve got a work of art in your jambs!
8. We Recalibrate Counterbalance Sash Weights.
Original double-hung windows function by means of a counterbalance weight system whereby the weight of each sash is counterbalanced by two weights housed in pockets on either side of the opening. For a variety of reasons, this counterbalance is frequently improperly calibrated. We weigh each sash and its corresponding weights to make sure they are exactly equivalent, adding or subtracting weight as necessary. It is singular pleasure to push or pull a sash up or down and have it respond with stop on-a-dime precision! If ever a person who has hired us to restore his or her windows is feeling ineffectual in life, all he or she needs to do is to open one of our windows to a precise location and let go. Such a gesture has the capacity to restore a person’s confidence in one’s ability to command attention and response!
9. We Prime The Sashes, Including The Rabbets Into Which The Glass Is Fitted.
One reason we use the highest quality oil-based paint we can find, is because our “long oil” primer takes 24 hrs to dry. This extended period of saturation enables the primer to soak deep into the wood. We are careful to prime the rabbets into which the glass is set and glazed. By doing so, we keep the oil in the glaze from soaking into the wood, thus keeping the glaze from prematurely drying out.
10. We Reinstall Existing Glass & Replace It If It Is Broken.
One hundred year old windows often have original, “wavy” glass. While there is a myth that says the glass is wavy because it is slowly melting, in fact, this waviness is a consequence of imperfections in the manufacturing process. One hundred years later, though, we have come to recognize the beauty in this “imperfection”
We use steam heat and infrared light to soften the glaze and remove the glass safely, thus enabling us to preserve much of this original glass.
But let’s slow down a bit. Because there’s a lot more involved in the process of removing and reinstalling glass. So let’s take a closer look.
After we had restored 26 windows in their vintage home, one client said…
“Couldn’t be happier with Oak Brothers. We hired them to restore all twenty-six windows original to our 1910 apartment….Most were pretty much inoperable; they’d either been painted or caulked shut or were missing counterweights, pulleys, and hardware. [After Oak Brothers restored them] … the sashes glide up and down like silk and fit snugly. We’ll definitely use Oak Brothers to restore the rest of our vintage home.”
– Dan Raeburn Hyde Park, Chicago