Convert double hung window to single hung

[boatshoes]

My house has 20-yr-old double-hung windows that are getting a little tired. The top sashes will sag until resting on the latch as the house goes through the heating and cooling of a normal day. They all seem to slide pretty well when I want them to.
Using HVAC almost all the time, I have no need for the top sash for ventilation. I would like to secure the top sash for air leak and sound reduction reasons. Can I just use trim screws at an upward angle through the bottom corners of the sash to secure them in the top position? Are there any concerns about poking a hole in the track/liner from the side? I would take the time to pre-drill for a cleaner entry.
I see that Marvin offers a double-to-single conversion kit that contains a stop and some carrier trim inserts so this would seem to be an acceptable method.
https://www3.marvin.com/WebDoc/UDH%20Single%20Hung%20Conversion.pdf

 

[brownbagg]

paint, chaulk, screws, nails, gorilla glue

 

[rlitman]

I wouldn't put screws through the sash. Just cut a block to fit under the sash and screw that into the track.

 

[K'ledgeBldr]

Maybe you could fix the balances...

 

[twistedstang]

Maybe you could fix the balances...

If it's a 20 year old window it probably doesnt have weights. I'm guessing the sash tracks on the side are all that hold them.

I just had my 100 plus year old double hungs reglazed and reroped. They should last another 100 years.

 

[egdede]

If it's a 20 year old window it probably doesnt have weights. I'm guessing the sash tracks on the side are all that hold them.

I just had my 100 plus year old double hungs reglazed and reroped. They should last another 100 years.

But now the glass is all flat, and everything looks like you are viewing it through a TV screen.

 

[K'ledgeBldr]

If it's a 20 year old window it probably doesnt have weights. I'm guessing the sash tracks on the side are all that hold them.

No. Im sure they're spring balances. And the wedge/pin anchor that attaches the spring to the sash is probably broken. Most were made of plastic and become brittle with age. Very rarely have I ever run across broken springs.

 

[ddawg16]

Nice thing about new windows.....better insulation....and reduction in noise.

 

[Stuart in MN]

I wouldn't put screws through the sash. Just cut a block to fit under the sash and screw that into the track.

This is what I've done, it works well and is simple enough to remove if desired.

 

[k1rodeoboater]

What rlitman and Stuart in MN said is the best course of action.

 

[yeldogt]

If they are indeed Marvin windows in good shape -- don't muck them up. Call Marvin and ask what the parts cost .... I have had good luck when I needed stuff.

The nice thing about the conversion kit is all the parts fit and it's a clean install. In an historic setting they were used to hide the vinyl track line

 

[rlitman]

...I just had my 100 plus year old double hungs reglazed and reroped. They should last another 100 years.

I'm in the process of restoring my 91 year old double hung windows. Reglazing for me doesn't require replacing the glass. Just replacing the putty. I'm keeping as much original glass as possible. Though I am replacing the putty with paintable "50 year" caulk. Yeah, I know it's sacrilege.

My biggest concern with operating old windows is the risk of lead. The sliding surfaces create a surprising amount of lead dust from the old paint. To this end, I've painted the parts that get painted with a self-priming polyurethane porch floor paint, after heat stripping as much as possible, in the hopes that will permanently contain the lead. But I also put strips of UHMW tape on the sliding surfaces of the frame, and I plan to replace the parting rails with strips I'm cutting out of a piece of King Starboard (UHMW sheet).

Between the UHMW tape and the brush seal tape I'm using on the sides, I hope to have these windows operating as smoothly and as well sealed as their vinyl counterparts.

 

[boatshoes]

No. Im sure they're spring balances. And the wedge/pin anchor that attaches the spring to the sash is probably broken. Most were made of plastic and become brittle with age. Very rarely have I ever run across broken springs.

All the ones I've examined have both springs still attached. They don't sag immediately under their own weight, just drift over time. Like the springs have lost some tension.

Manufacturer unknown, I didn't find any names on the sashes when I pulled them out. Where would I look for that info?

I would love new windows but cost-prohibitive in comparison to delrin blocks and screws, especially in the current economic environment. Thanks all for your input.

 

[rlitman]

...I would love new windows but cost-prohibitive in comparison to delrin blocks and screws...

Delrin is expensive, unless you've got a lot of it. Azek PVC trim comes in small affordable pieces that cut easily. There's even cheaper plastic trim molding available that will also work.

 

[twistedstang]

I'm in the process of restoring my 91 year old double hung windows. Reglazing for me doesn't require replacing the glass. Just replacing the putty. I'm keeping as much original glass as possible. Though I am replacing the putty with paintable "50 year" caulk. Yeah, I know it's sacrilege.

My biggest concern with operating old windows is the risk of lead. The sliding surfaces create a surprising amount of lead dust from the old paint. To this end, I've painted the parts that get painted with a self-priming polyurethane porch floor paint, after heat stripping as much as possible, in the hopes that will permanently contain the lead. But I also put strips of UHMW tape on the sliding surfaces of the frame, and I plan to replace the parting rails with strips I'm cutting out of a piece of King Starboard (UHMW sheet).

Between the UHMW tape and the brush seal tape I'm using on the sides, I hope to have these windows operating as smoothly and as well sealed as their vinyl counterparts.

Nice! Mine were also completely stripped of paint inside and out. I love my old wavy glass. My window guy added some hidden silicone weather stripping to both sashes.

 

[rlitman]

Nice! Mine were also completely stripped of paint inside and out. I love my old wavy glass. My window guy added some hidden silicone weather stripping to both sashes.

I wish I had a “window guy”. This is a whole lotta work.

 

[twistedstang]

I wish I had a “window guy”. This is a whole lotta work.

He wasnt cheap! 1000 per window for him to free the sashes, strip, finish, reglaze, add the weather stripping, re-rope, and new parting strips.

 

[K'ledgeBldr]

All the ones I've examined have both springs still attached. They don't sag immediately under their own weight, just drift over time. Like the springs have lost some tension.

Manufacturer unknown, I didn't find any names on the sashes when I pulled them out. Where would I look for that info?

I would love new windows but cost-prohibitive in comparison to delrin blocks and screws, especially in the current economic environment. Thanks all for your input.

You'll probably find your parts here-

https://www.strybuccatalogs.com/catalogs/Strybuc-Catalog-2020/#p=153

 

[HenryAZ]

Using HVAC almost all the time, I have no need for the top sash for ventilation. I would like to secure the top sash for air leak and sound reduction reasons.

Isn't there a latch where the two sash meet in the middle? If you don't want the windows open at all when on HVAC, just latch the latch. When you do want a window open for ventilation, my personal preference would be to open the top sash, as heat rises and would exit the top better.

 

[yeldogt]

Isn't there a latch where the two sash meet in the middle? If you don't want the windows open at all when on HVAC, just latch the latch. When you do want a window open for ventilation, my personal preference would be to open the top sash, as heat rises and would exit the top better.

single hung have the bottom operational

 

[yeldogt]

I'm in the process of restoring my 91 year old double hung windows. Reglazing for me doesn't require replacing the glass. Just replacing the putty. I'm keeping as much original glass as possible. Though I am replacing the putty with paintable "50 year" caulk. Yeah, I know it's sacrilege.

My biggest concern with operating old windows is the risk of lead. The sliding surfaces create a surprising amount of lead dust from the old paint. To this end, I've painted the parts that get painted with a self-priming polyurethane porch floor paint, after heat stripping as much as possible, in the hopes that will permanently contain the lead. But I also put strips of UHMW tape on the sliding surfaces of the frame, and I plan to replace the parting rails with strips I'm cutting out of a piece of King Starboard (UHMW sheet).

Between the UHMW tape and the brush seal tape I'm using on the sides, I hope to have these windows operating as smoothly and as well sealed as their vinyl counterparts.

In the old days the sash tracks got oiled and waxed ..... paint build up on the frame and sash would make them stick. Not painting the edge of the sash and frame would allow for drying.

I'm afraid you may run it to problems with caulk .... you get get the best glazing products online and once you get the hang of it ... it's rewarding ...

 

[rlitman]

single hung have the bottom operational

Right, and there are situations where double hung would historically have been impractical, such as a half-round top upper sash, or where the upper sash is just too high to reach or is too large to move. And there are situations where architects choose to remain faithful to authentic architectural styles.

But for the most part, aside from saving a few bucks on hardware, it just isn't worth choosing a single hung window over a double, which is why you don't see too many single hung windows out there, so I get where this confusion is coming from.

As for the OP, as was pointed out above, his spring balances are reaching retirement age, and he has several options to deal with this.

I suggested the quite easily undone option of blocking the upper sash in place. One down-side is now the upper is inoperable. The other down-side is that with the balances going, there's a real possibility that the lower sash may slam down unexpectedly.

The gold standard fix would be to replace all of the tired balances. Depending on the window, this may be easy and cheap or difficult and expensive.

 

[rlitman]

In the old days the sash tracks got oiled and waxed ..... paint build up on the frame and sash would make them stick. Not painting the edge of the sash and frame would allow for drying.

I'm afraid you may run it to problems with caulk .... you get get the best glazing products online and once you get the hang of it ... it's rewarding ...

Yes, the tracks would get waxed, and the hidden (left and right) edges of the sashes do not even get painted. UHMW tape beats wax any day of the week. The brush seal tape I found on Amazon glides on the UHMW perfectly, and my UHMW parting bead leaves me one less part to paint and tape. The first window I assembled the other day slides with less stiction than any new windows I'm familiar with, and seals just as tightly. I'm quite proud of the results.

As for drying, that's not a concern for me. My original wooden windows are all either covered by triple track aluminum storms, or open onto an enclosed porch.

I've done my own re-puttying with oil based glazing compound in years past on many a window. I'm well versed in the technique of keeping a ball of it warmed in one hand. It just doesn't hold up well. By the end of 10 years, it's shrunk and starts the process of falling out, and I'm sick and tired of it. And yes, I always either use an oil based primer on the sash before glazing, or oil the sash with linseed oil first so it doesn't dry out the putty, and then cover with oil based primer and top coat. I just don't have the time or money to stay on this repair treadmill.

So, I chose to go with polyurethane caulk. Time will tell how well it holds up. I've had several pairs of shoes with polyurethane soles disintegrate on me, so I know that there are no guarantees out there. However, I've never seen the polyurethane glazing on a car window fail yet, and I'm quite familiar with working that stuff. It's MUCH easier than putty glazing, though certainly quite different when it comes to tooling.

However, to your point, if these windows were exposed to the weather, I'd be a little concerned about the polyurethane trapping water and leading to rot.

 

[yeldogt]

Most old windows had both sash movable .. even large church windows. My current project is an old church and all the gothic windows are double .. two are triple.

Over time they get mucked up. Over painting -- is the biggest problem ..and why most don't work. At some point they need to get stripped and painted properly


SARCO -- that the glazing I like. They make at least two types .. I also use it for wood filler in old windows after priming and before latex paint. Most wood fillers are too hard and pop out --

 

[HenryAZ]

single hung have the bottom operational

Yes, a manufactured single hung is bottom operational. But the OP is dealing with a different situation, where he is converting a double hung. He can make it bottom or top operational. There's no reason to make it bottom operational just because that is the industry definition.

 

[boatshoes]

Yes, a manufactured single hung is bottom operational. But the OP is dealing with a different situation, where he is converting a double hung. He can make it bottom or top operational. There's no reason to make it bottom operational just because that is the industry definition.

Right, I'm making it bottom operational because the top drifts over time due to its age. I don't see anything broken and it's probably time for new springs but securing the top sash shut when I don't even use it is what makes the most sense due to cost. Screws and blocks are most easily reversible as well.
I attached a picture showing the latch, you can see the drift in the misalignment of the two pieces.

 

[Dustball]

I took a look at my window. Could you cut a piece of PVC/plastic square stock to put inside the track on one side of the window to force it to stay up?