Window Standards Outline

Here we are developing the overall outline of the document.
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Window Standards Outline

Postby johnleeke » May 9th, 2011, 2:20 pm

In this discussion the Founders are developing the outline for the document.

(See below for the latest version of the outline, under "Attachment" where you can click and download it.)

We have begun with each of us posting a simple listing of the steps we go through to completely refurbish a wooden double-hung window.

I have combined them into a "master list" and then broken it down into major headings, sub-headings, etc, in a standard outline format.

Now we are reviewing and developing the outline.

Then we can begin to fill in the outline with write ups for each item in the outline.

To comment, click on "Post Reply" below.

If you are putting a lot of time and thought into your message, before you press <Submit>, make a backup of your message
by selecting and copying the body of your message to your clipboard and to a word processing document. This way you have an easy recovery if the text is lost. Or, better yet, make your list in your word processing program, then copy and paste it into the message here at the Forum.
Window Standards Outline, version 0.1, pdf file
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Re: Window Standards Outline

Postby johnleeke » May 9th, 2011, 2:22 pm

Remove sashes from frame, install temporary weather panel
Move sashes to onsite or remote workshop
Remove heavy paint buildup from frame and sill
Repair sills, paint sills and frames
De-glaze (remove glass) sashes, remove paint, cleanup
Mill out stock for replacement sash parts
Cut & fit stock for each sash repair
Repair wood of sashes
Re-glaze and paint sashes
Move sashes back to site and distribute to window locations
Re-install sashes in frame and tune up for proper operation
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Bob Yapp
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Joined: May 9th, 2011, 8:39 am

Re: Window Standards Outline

Postby Bob Yapp » May 16th, 2011, 9:11 am

Bob Yapp’s
Basic Double Hung Window Restoration & Weatherization Steps

Assess condition of entire window opening
Remove wood or aluminum storm window
Set up for lead safe paint removal-exterior
Remove all paint from exterior portion of window opening with IR devise
Make wood repairs-dutchmen or epoxy
Vacuum and tack storm bed, exterior casing & sill
Oil prime storm bed, exterior casing & sill
Apply two topcoats acrylic latex paint with 43% solid content or higher
Measure for new wood storm window or repair and paint existing wood storm
Make, fit and paint new wood storm
Weather strip wood storm
Install repaired wood storm or new wood storm
Set up for safe lead paint removal-interior
Remove both sashes-save interior stop and discard parting stop
Take both sashes and interior stop to shop
Remove hardware and boil paint off as needed
Remove all putty, paint (sashes & interior stop) as needed with IR devise
Inspect stiles, rails, muntins, mortises & tenons for soundness
Re-pin mortise & tenon joints as needed
Make Dutchmen and/or epoxy repairs
Rout 3/32” slot in upper sash meeting rail face, top of top rail of upper sash and bottom
of bottom rail of lower sash
Rout 5/32” slots on both sides of two sashes for ribbed track system
Cut and pre-drill ribbed metal tracks
Cut and counter sink screw holes in new pine parting stop
Drill ½’ holes in original interior stop for stop bead adjusters
Oil prime sash including glazing bed as well as interior stop & parting stop
Install t-flanged rubber gasket at meeting rail top sash upper rail & bottom sash lower rail
Clean original glass and/or cut salvaged glass to match original
Bed glass into acrylic latex siliconized/paintable caulk
Install glazing points
Razor blade off bedding caulk squeeze out
Install boiled linseed oil based glazing putty
Apply air from box fan over glazing putty
Clean putty oil from glass with saw dust & paper towels
Apply two topcoats acrylic latex paint with 43% solid content or higher to sash, and stops
Take sashes, stops and track system back to widow opening
Remove all paint from interior portion of window opening with IR devise as needed
Make wood repairs
Vacuum and tack jamb and stool bed, exterior casing & sill
Oil prime jamb & stool as needed
Apply two topcoats paint with 43% solid content or higher as needed
Open weight pocket access panels
Remove sash weights
Vacuum out sash weight pocket
Install 4 new cotton sash cords
Install upper sash with ribbed metal tracks
Screw tracks to jamb with #4 phillips head sheet metal screws
Install and screw in parting stop with brass slotted screws
Install lower sash with ribbed metal tracks
Screw tracks to jamb with #4 phillips head sheet metal screws
Install interior stop
Clean all areas

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Re: Window Standards Outline

Postby johnleeke » May 17th, 2011, 9:01 am

David Gibney - Window Restoration of Double Hung units

Formatted version:
DGibney-window rest steps5911.docx
(23.15 KiB) Downloaded 373 times

Plain text version:

Site visit, inspect the windows interior and the exterior conditions. Write a condition assessment report.
Give the customer an estimated cost for restoration of sash, frames, sills and weatherization of window units. Proposal accepted.

On Site work

Remove the window stop and parting strip from the window frame using the utmost care. Number the components for re-installation.

If the windows have pulleys, ropes or chains that are in good condition, remove them carefully from the sides of the sash. Tie a knot on the end of the rope or chain so it will not slip though the pulley and will be ready for reinstallation.

Remove upper and lower sash. Number upper and lower sash and the window location. Check the existing window frame opening for being square. Make note if the frame is out of square and the extent of it. Make note of sash that has excessive play side to side or if the meeting rails are not meeting correctly.

Install a temporary window covering in the opening. Remove window pulleys if they are going to be cleaned. Remove unnecessary hardware and trim. Scrape excessive paint build up smooth within the jamb area.

Remove all sash to shop and install numbered metal tags on each sash.

Shop Work

Remove the glass using the Putty Softener tool from CR Laurence Co. Our success rate is 99% removal without breakage. The Fein Tool with scraper blade, along with the cordless Makita miniature circular saw can also be used to cut out the glazing. Our success rate for this method of removal is also 99%.

Clean salvageable cylinder/crown glass and tape together glass from each sash. Number the set to match sash number and store safely.

Chemically strip all paint to the bare wood using the cold tank stripping method . Then chemically neutralize them and allow to air dry to a 10% moisture content. Test for Ph and re-neutralize if necessary. Always take one sash to the stripper for a test run to check their quality of work before you have all of the sash stripped.

Inspect sash, and mark needed repairs with a black marker. Set off into groups from minor to moderate to more time consuming repairs.

Machine a molding head cutter knife blade to match the exact profile of the muntin for the sash so that muntin stock, stiles and rails can be made up for necessary repairs.

Make a list of lineal footages needed for repairs, muntin, rails and style stock. Machine all replacement stock and place with correct sash.

Carefully take the sash apart. Punch wood pegs loose and save for future reinstallation. If the frame has been pinned together with steel pins, identify them and carefully punch them through.

All repairs to the sash should use the following methods:

1. Total replacement only if necessary for muntins, styles, or rails due to excessive rot or damage.
2. For minor rotted areas, remove damage to a stable substrate and install a wooden Dutchman using salvaged materials from first growth sash where possible. Bond material to original member using an epoxy adhesive, sand smooth to original surface.
3. Apply a very thin skim coat to vulnerable weathered areas on the sash frame with an epoxy filler to make the surface smoother so that moisture will not collect.
4. Replace missing or rotted tenons with a new tenon, glued in with epoxy.
5. Laminate a new member on an existing stile or rail to replace a rotted or missing mortise area so that an original or repaired tenon can be inserted.
6. Replace rotted or damaged existing muntins by installing a Dutchman within the given area or total replacement of a part if necessary. Replace broken or missing glazing bars.
7. For window sash that were removed from a opening that was noticeably out of square, or the meeting rail was not meeting up even, laminate with an epoxy adhesive a 1” tall by the thickness of the window piece to the top of the upper sash and the bottom of the lower sash so that they can be scribed to the original opening for a weather tight fit at the top and bottom sash and at the meeting rail.
8. For sash that had excessive play in the width of the window opening, install ½” strips to the sides to allow a custom tight fit on reinstallation.

After all the components of a sash are repaired or replaced, the sash is now ready to re-assemble
Connect the mortises and tenons on the four outside corners using epoxy adhesive. Install original wooden pegs. Place the sash is flat on a work table, square up and brace it until the epoxy dries. Only the corners should be glued. No muntins are glued together; they should be free to float within the frame.

Inspect sash and remove excess epoxy. Sand all components smooth.

Spot prime any exposed epoxy patches using Bulls Eye Zinzer primer or a similar product that will bond to smooth surfaces. Regular oil and latex primer will not bond to exposed dried epoxy.

Install one coat of a mixture of 60% paint thinner and 40% boiled linseed oil. Allow to completely dry for one to three days depending on humidity and temperature. This treatment puts resins back into the wood fibers. Extremely dry wood sucks the binder out of the oil base primer causing the primer to lift off the surface which is responsible for early paint failure.

Install one coat of a high grade oil base primer, thinned by 10 to 15% to allow deeper penetration into the wood fibers.

Install one finish coat of a high grade exterior paint, either acrylic, industrial or European oil based, on the entire exterior surface.

Install a thin bead of acrylic caulk as back glazing in the bed area to receive the glass. Allow sash to sit for 12 hours so the caulk can set up firmly, glass is bonded in place. Scrape excess caulk from the glass and the glazing area. I do not install push points to eliminate the risk of breaking glass.

Install the exterior glazing, tooling to a smooth surface with clean corners. No glazing should be seen from the interior side of the sash.

Clean sash well and remove to job site.

Restoration of existing frames, sills and exterior casing

Existing window sills, sub sills and window jambs can always be repaired in place in a wood or masonry structure.

Repair minor rot in existing sills, sub sills and jambs by first removing damaged areas. Install a wood Dutchman using black walnut, Spanish cedar, mahogany or a similar water resistant wood, by laminating it to the sill with an epoxy adhesive. Let it cure and sand smooth to the existing surface.
If total replacement is required of the sill, use black walnut, Spanish cedar or Douglas fir as a replacement material. Cut a drip line on the underside of the front of the sill ½” in from the face 3/16” wide by ¼” deep. Back prime all new sill prior to installation.

If there are weathered grooves on the component, remove all paint completely. Skim coat with an epoxy filler, only filling the grooves so that the sills will be smooth after sanding is complete. It is very important that the sills have a smooth surface to shed water.

New sills should be fastened to bottom side of jamb with a combination of stainless steel finish screws and epoxy adhesive to bond the new sill well to the existing jamb.

If there is a heavy paint built up on the sills, jamb and trim, total paint removal should be recommended to achieve a long lasting exterior paint job.

The layers of paint can safely be removed with the use of a heat gun or a Silent Paint Remover with the aid of sharp paint scrapers.

Spot prime all exposed epoxy repairs with a primer that sticks to any surfaces, such as the Bulls Eye Zinzer products.

After complete paint removal apply one coat of the linseed oil/paint thinner to all the surfaces, let dry for 2 to 3 days. Apply a high grade oil base primer to all the surfaces.

Apply two finish top coats of a high grade latex acrylic or and oil base European paint
Installation of sash/Weatherization

Install weatherization where ordered as follows:

I use high grade products supplied by Resource Conservation Technology Inc. located in Baltimore Md. All the weather stripping is permanently installed by a friction snug fit into a 1/8” wide by ¼” deep groove cut into the sash.

Custom fit sash that are being placed in an out of square frame, excessive side to side play and get the meeting rails to line up prior to the installation of weather stripping.

Install Brush Seal WS74 on the sides of the upper sash to fit snugly against the side jambs stopping any air infiltration.

Install Tube Seal WS10 on the top rail of the upper sash to fit snugly to the top of the jamb stopping air infiltration.

Connect ropes or chains to the upper sash. Fasten to the original location on the sides of the sash with a knot and box headed nail, # 4 into the knot or 1” screws for chains. Use a new high grade waxed cotton sash cord #8 [1/4”] or #10 [5/16”]. Use original sash chain, or if new chain is necessary, use a solid sash chain #45, #25 or #3. Install the correct length of chain or rope and oil the pulleys for smooth operation.

If the customer does not want a functional upper sash, it is recommended that the window weights still be connected for future operation. Caulk the upper sash in place at the parting strips using high grade acrylic caulk wiped smooth. The brush seal WS74 does not have to be installed on the sides of the sash.

Install Tube Seal WS32 on the exterior side of the lower sash meeting rail ½” from the top of rail. It is recommended to use adhesive caulk into the groove to bond the tube seal in the groove due to the friction of the meeting rails coming together.

Install Tube Seal WS11 on the bottom rail ½” in from the face.

Using a 1” screw and washer, install ¾” x 2” piece of backer rod in the groove on the sides of the lower sash where the rope enters so backer rod is flush with the top of the meeting rail. This stops air infiltration around the rope or chain area. A small piece 1”x1” of felt weather stripping can also be installed on top of the ends of the meeting rail to fit tightly around the parting strip to stop air infiltration.

Install Brush Seal WS74 on the back of the window stop, facing the sash, to the height of the lower sash. Window stop is reinstalled so that it fits snugly against the face of lower sash, but allows smooth movement and it stops air infiltration where to sash meets the window stops.
Cotton balls or rope caulk can temporally be installed in the pulley openings during the heating or cooling season to stop air infiltration. I am presently working on two positive methods of weatherization for the pulleys that will be a permanent fix so customer will not have to deal with the pulley weatherization issue.

Install ropes or chains.

Wax sides of all sash for smooth operation.

Install a premium sash lock at the meeting rails to pull tight against the weather seal tube and push the bottom of the lower sash tight against the sill to stop air infiltration.

After the sash have been installed and final exterior painting is completed, clean all glass.

Inform the customer that the sash should be inspected every year for maintenance, especially the bottom of the lower sash to keep moisture from wicking into the bottom rail and ends of the styles causing failure to the mortise and tenon joinery of the lower sash.

Weatherization of the Exterior Window surround

Masonry, Stone or Brick

If masonry pointing is in good shape, rake out a fine groove between the pointing and the window frame surround, 1/8” wide by ¼” deep. Apply a high grade urethane caulk the same color as the masonry pointing around the entire window frame.

If the pointing has failed around the window unit, rake out the masonry joint that surrounds the window frame. Install ½” to ¾” backer rod in the raked out joint, recessed from the face of the window frame ¾” of an inch. Re-point the joint with mortar that matches the color of the existing pointing. Let the joint dry for 2 to 3 days, rake out a fine joint around the window frame 1/8” wide by ¼” deep. Apply a high grade urethane caulk same color as the masonry pointing.

Wood frame structure

It is important to seal the space where the siding meets the window frame. Scrape out any failed caulk first and spot prime any bare wood prior to the installation of a high grade acrylic caulk where the siding meets the window surround.

Exterior and Interior Storms

If the structure has existing functional storm windows, consider keeping the storm windows. They help a little with weatherization issues and also can help protect the sash.

If the structure does not have storm windows I do not recommend the purchase of storm windows for the following reasons:

1. They impact the authentic appearance of the historic structure. The real beauty of the window sash and old glass is not as visible.
2. They add very little R value. Statistics show one a positive return on the investment takes many years. The key is to stop air infiltration with weatherstripping.
3. They can possibly cause condensation which can cause rot by dripping onto the sill and sub sill.

For air flow and ventilation, screens can be custom made to fit the lower sash.

I do not recommend interior storm windows because they also interfere with the visible beauty and historic appearance of the sash and old glass. They can also cause interior condensation which can rot out the interior window stool and components of the upper and lower sash.

Copyright 2011 David Gibney

Posts: 374
Joined: April 13th, 2011, 7:34 pm
Full Name: John Leeke
Location: Portland
Organization: Historic HomeWorks
Permissions: Yes
Location: Portland, Maine

Re: Window Standards Outline

Postby johnleeke » May 18th, 2011, 4:05 pm

Sash Restoration Steps, Duffy Hoffman

Map and number sash- on site/number glass and number sash on tape, put on glass. Inspect window opening for shop adjustments and site frame adjustments.

When sash gets to shop use number and letter stamps and transfer number to side of stile. Use evolution sheet to note significant wood repairs, glass, etc.

Removal of sash-
pull stop/ number left and right w/ sharpie(magic marker)
Remove lower sash/ if painted shut un stick.

Remove parting bead/ unstuck upper sash, pull down so you are below pulleys, push and pull sash up down to remove. Follow numbering from top. Inspect pulleys for proper operation.

Paint glazing and glass removal-

Paint, glazing and glass removal- make sure you test the removal method in which you are using. Before continuing, while sash coatings are still soft remove sash hardware from sash. Save screws and hardware put in paint remover while restoring sash. At the end of sash restoration rinse hardware and screws, let dry and wire wheel to original look.

Remove glazing/putty first (no more than 15% glass breakage) soak glass/clean glass when before you install it back in sash. Remove all paint coatings and stain.

Wood and epoxy repair/ inspect use a repair sheet- most common repairs and damage-
Mortise and tenon rot or loose joints/ inspect and repair. All cracks in joints should be epoxy consolidated and impregnated. Dutchman repairs as need. When repairs depending on structure exceed the cost of replicating a new sash exactly like the original one do so.(in some cases like the first Christ church of Philadelphia as an example restore it.

Epoxy repair- always square sash before using epoxy or while making repairs. use the epoxy that is flexible in moving parts of sash and a resin based on holes, muntins etc.

Fine tuning of frame and muntins. Sand all muntins and frames of a sash before priming.

Prime sash with linseed oil primer coatings. Prime interior and exterior.

Re-sand again to refine for finish coatings.

Glass installation- vac and wash sash. Clean glass/ cut replacements in kind as you are doing installation. Check fit of each pane of glass then apply a bead of elastomeric caulk in rabbit, install glass, bed glass in caulk and remove extra caulk. Pin glass with glazing points.

Apply a second coat of primer to exterior of sash seal glazing putty with primer to glass. Sand again when dry. Let putty glaze over.

Finish painting- apply two coats of 100% latex acrylic paint to interior of sash/ apply two coats of oil finish paint to exterior of sash.

Trim and clean glass and do not break paint seal to the glass.

Copyright 2011 Duffy Hoffman

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