Weatherstrip, Ribbed Metal & Rubber Gasket (final)

Controlling the movement of air and heat through windows.
johnleeke
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Weatherstrip, Ribbed Metal & Rubber Gasket (final)

Postby johnleeke » August 21st, 2012, 12:02 pm

Number:
Update:
Author: Bob Yapp
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Title of Treatment: Weatherstrip, Ribbed Metal & Rubber Gasket
Class of Treatment: [ ] Maintain, [ ] Stabilize, [ ] Repair, [x] Upgrade, [ ] Exception
Type of Treatment: [ ] Traditional, [x] Contemporary

Condition to be Treated:
Air infiltration around primary double hung window sashes.

Description:
This treatment is based on the traditional ribbed metal system with the addition of contemporary rubber gaskets at the rails. The traditional system has interlocking metal at the meeting rails and a ribbed metal flange tracks at the sides of the sashes. It appears to be the oldest double hung window weather stripping system, with patent, advertising and installations dating back to the late 19th century.

Typical Procedure:
1. Check sash for side to side play (movement) in the jamb opening. This can vary between 1/8" and 3/8" on well maintained windows. If the side to side play exceeds 3/8" consider either a jamb repair or adding matching wood to each side of the sash to reduce the side-to-side play. Check sashes for vertical play from top to bottom with both sashes in place. For the meeting rails to meet properly in the middle at completion there should be no more than 1/4" and no less than 1/8' play overall from top to bottom. If there is more or less play than this the top or bottom rails may need to be added to or trimmed.

2. Slot the parting stop on its interior face for the back edge of the flange of the ribbed metal track of the lower sash to fit into. Pre-prime and paint the parting stop and countersink the stop for a #6 screw. The parting stop is screwed in so it can be easily removed for future maintenance of the sashes and jamb.

<see photos below>
Original 1892 parting stop and new with slot for metal track flange

3. Rout a groove on both sides of each sash. Size the grooves in width and depth to work with the specific ribbed metal track in use. The lower sash slots are closer to the interior face of the lower sash and the slots on the upper sash are closer to the exterior face of the sash.

4. Rout narrow slots for the rubber tube weatherstripping. Size the slot width and depth to work with the specific rubber tube weatherstripping used. Rout a slot in the meeting rail of the upper sash dead center. Rout slots along the bottom edge of the lower sash bottom rail and the top edge of the upper sashes top rail.

<see photos below>
Typical rubber tube weather stripping

<see photos below>
Rubber tube weather stripping installed in the check/meeting rail of upper sash

5. Cut four metal track pieces the height of each sash plus 3/8", using tin snips. Cut an angle on the bottom of the two lower track pieces that matches the angle of the bottom of the jamb.

6. Pre-drill holes between the corrugations of the lower metal tracks. Size the holes with a diameter that is slightly smaller than the head of the #4 sheet metal screw that will attach the track to the side of the jamb for each sash. This oversized hole creates a counter sink in the thin metal and allows for adjustment when installing the sashes. For the two lower sash tracks drill one hole 1/4" down from the top and 1" up from the bottom and then one hole at the center.

7. Cut out a gap for the sash pulleys in the two upper track pieces. Put the tracks in place and mark the track for the top and bottom of the pulleys. Cut the two marks all the way to the rib, using tin snips. Score several times against the rib between these two cuts with a sharp utility knife. Bend this cut metal several times back and forth until it breaks loose. Dress sharp edges smooth with a bastard file.

8. Pre-drill holes between the corrugations of the upper metal tracks. Drill them between the corrugations slightly smaller than the head of the #4 sheet metal screw that will attach the track to the side of the jamb for each sash. Drill one hole 1" from the top, one 1/2" above the pulley, one 1/2" below the pulley, one centered and one 1/4" from the bottom.

<see photos below>
Screws go between these corrugations

<see photos below>
1892 track system cut out around pulley with #4 sheet metal screws

9. Attach sash cords or chains to the upper sash and slip the tracks into their slots over the cords or chains. Ease the sash, with tracks, into the upper opening and screw the track to the jamb with #4 screws. Adjust track as needed and test for ease of operation. Cut the ends of the rubber tube weather stripping on the upper sash meeting rail and top rail so they just touch the tracks on both sides. Install the rubber tube.

10. Install the parting stop, with flange slot facing inward, using a #6 screw.

11. Attach sash cords or chains to the lower sash and slip the ribs into their slots over the sash cords. Ease the sash, with tracks, into the lower opening and into the parting stop slot. Screw the track to the jamb with #4 screws. Adjust track as needed and test for ease of operation. Cut the ends of the rubber tube weatherstripping on the lower rail it just touches the tracks on both sides. Install the rubber tube.

12. Test upper and lower sashes for ease of operation and install a sash lock that brings the meeting rails close enough together to compact the rubber tube weather stripping at the meeting rail. If air can be felt at outside of meeting rails, add small felt or rubber patch over this area with small screw to the top of the lower sash's meeting rail.

Materials:
· Weatherstrip, ribbed metal flange track material
· #4 x 1/2" sheet metal screws, flat head
· #6 x 1-1/4" screws, flat head
· Rubber tube weather stripping with t-flange or barbed flange
· Parting stop to match original, if needed

Quality of Results:

Best Work:
The sashes are snug with a slight amount of play, they move up and down with one finger. The ends of the rubber tube weatherstripping just touch the tracks and the sash lock pulls the meeting rails snugly into the rubber tube weatherstripping. No air infiltration can be detected.

Inadequate Work:
Sashes have an in-and-out horizontal motion of more than 1/16"; rubber does not touch metal tracks; window is hard to operate (more force than can be applied with one finger); sash lock does not bring meeting rails to the rubber; air infiltration can be detected.

johnleeke
Posts: 375
Joined: April 13th, 2011, 7:34 pm
Full Name: John Leeke
Location: Portland
Organization: Historic HomeWorks
Permissions: Yes
Location: Portland, Maine
Contact:

Re: Weatherstrip, Ribbed Metal & Rubber Gasket

Postby johnleeke » August 21st, 2012, 1:27 pm

Bob,

OK, a lot of edits on this one. Check it over carefully to assured it's all there.

Please respond to my comments by posting a message.
John
Standards Co-Founder
Standards Editor

http://www.HistoricHomeWorks.com

Bob Yapp
Posts: 59
Joined: May 9th, 2011, 8:39 am

Re: Weatherstrip, Ribbed Metal & Rubber Gasket

Postby Bob Yapp » August 27th, 2012, 1:09 pm

Too much slop is an in and out motion of 1/16" or more. #4 screws are 1/2". Best operation when done is to lift the sash with literally one finger. If it is tighter than that the stile may be bowed or the slot is not wide enough for the track. Everything else looks good.

Bob
Attachments
Ribbed Track Installed with #4 Sheet Metal Screws.JPG
Ribbed Track Screww Location.JPG
Santoprene Gasket Material.jpg
Santoprene installed in the upper sash meeting rail.jpg

Bob Yapp
Posts: 59
Joined: May 9th, 2011, 8:39 am

Re: Weatherstrip, Ribbed Metal & Rubber Gasket

Postby Bob Yapp » August 27th, 2012, 1:11 pm

Pully cut out
Attachments
Ribbed Tracked Cut Out For Pulley.JPG


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