Muntins, which one is solid?

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wobblycogs

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I'm designing some new sash windows and I've got a dilemma. Each sash is 2x2 so it's got a horizontal and vertical muntin. Since I don't plan on trying any fancy half lapping that means either the vertical or horizontal will have to be M&T'ed in at the middle. The question is which muntin is the solid one?

I can see benefits to both alternatives but I slightly favour making the vertical muntin solid since that is the direction of the forces when the window is opened and closed.

I've had a quick google for the answer and, as I suspected would be the case, my first few hits were completely divided in opinion (and all of the articles were from respectable sources).

I have a feeling this question could cause a holy war and I apologize in advance if it does.
 
I believe the vertical stretcher is the mullion and the horizontal known as the muntin. I would suspect in your case, a 2 x 2 window the location of the M&T is irrelevant. However had the mullion been the longer of the two I would personally favour mortising the longer stretcher. (assuming you are building the sash with one mullion and one muntin)

Wikipedia - A muntin is a strip of wood or metal separating and holding panes of glass in a window.[1] Muntins are also called "muntin bars", "glazing bars", or "sash bars". Muntins can be found in doors, windows and furniture, typically in western styles of architecture. Muntins divide a single window sash or casement into a grid system of small panes of glass, called "lights" or "lites". :duno:
 
wobblycogs":1zuv5qyc said:
... I slightly favour making the vertical muntin solid since that is the direction of the forces when the window is opened and closed.

...
Yes thats the way to do it. NB "glazing bars" not muntins.
 
The first problem is I am not sure where we are in the frame or the sash. If it is a frame then the vertical divider is a mullion and the horizontal a transom. If in the sash it is a glazing bar. That said if you are dividing the frame into four sashes I would run the mullion through and divide the transom unless the transom projects beyond (is wider than) the mullion when I would do it the other way around. If it is a sash I run the horizontal glazing bar through otherwise there is a great load on a very small tenon.
Good luck!
 
To clear up any confusion, I'm talking about the the glazing bars - those bits of wood that divide up the sash into smaller panes of glass. I've always known then as muntins although I admit I tend to read older woodworking books. Mullions I always took to be more substantial vertical members that divided up the frame.
 
There are no mullions, muntins or transoms anywhere in a sash window.
The glazing bars always go through vertically to resist the load of pulling them up and down. It makes for a very strong unit which means the timbers can be very slender, compared to a light with no glazing bars such as you might find in an Edwardian building.
 
Down here, in sunny Devon, And according to Wikipedia, The muntin or main glazing bar is solid and the vertical divider(s), As you say for strength.
The horizontal glazing bars are stub tenoned, into the upright muntin, or bar, (it's the same thing)! and the moulding is scribed, to maintain some strength.
Regards Rodders
 
I don't have any direct experience of making sash windows but I do have a selection of reference sources.
If I have read it right, the old anonymous booklet "Window Making" - as rediscovered by Richard Arnold and reprinted by Lost Art Press - shows the horizontal glazing bars as single pieces, mortised, with the vertical bar being cut into short pieces with tenons on.
In contrast, the booklet "Windows" published by the Building of Bath Museum, shows normal construction in Bath as having the vertical bars as single, mortised pieces and the horizontals cut into separate bits. Roy Underhill says the same in "The Woodwright's Companion."
Several other books ignore the question!
 
Jacob":3u0jv477 said:
There are no mullions, muntins or transoms anywhere in a sash window.
The glazing bars always go through vertically to resist the load of pulling them up and down. It makes for a very strong unit which means the timbers can be very slender, compared to a light with no glazing bars such as you might find in an Edwardian building.


As Jacob says, opening or sliding windows have muntins, or glazing bars, within.
Mullions fit in a window frame, vertical, between windows within the frame, and a transom, horizontally, divides the opening window from a window above it, or divides a door frame from a window (s) above it.
Regards Rodders
 
Jacob":2q59xgmh said:
There are no mullions, muntins or transoms anywhere in a sash window.
The glazing bars always go through vertically to resist the load of pulling them up and down. It makes for a very strong unit which means the timbers can be very slender, compared to a light with no glazing bars such as you might find in an Edwardian building.

Jacob you better let George Ellis know he does not know what he is talking about at page 206
 
Oh OK except for mullions between (very rare) "venetian" sashes. No transoms or muntins however.
 
PAC1":279yj27i said:
Jacob":279yj27i said:
There are no mullions, muntins or transoms anywhere in a sash window.
The glazing bars always go through vertically to resist the load of pulling them up and down. It makes for a very strong unit which means the timbers can be very slender, compared to a light with no glazing bars such as you might find in an Edwardian building.

Jacob you better let George Ellis know he does not know what he is talking about at page 206

Not having George Ellis works to hand, Any chance of a butcher's at page 206 please?
Sounds interesting.
Regards Rodders
 
Ive always thought a mullion and transom are parts of a casement frame. Ive always used the term muntin to describe a vertical component of a door that fits between 2 rails. So on a typical 4 panel interior door there would be 2 muntins.

I would generally tend to make the horizontal glazing bars run through and have the vertical bars in short pieces. The reason is simply because it would be natural to tenon the top rail, bottom rail (or meeting rails in the case of a sliding sash) and horizontal glazing bars all with the same shoulder length. Once a sash is glazed, the seal between glass and rebate will provide the strength.
 
RobinBHM":2qmedkd9 said:
Ive always thought a mullion and transom are parts of a casement frame. Ive always used the term muntin to describe a vertical component of a door that fits between 2 rails. So on a typical 4 panel interior door there would be 2 muntins.

I would generally tend to make the horizontal glazing bars run through and have the vertical bars in short pieces. The reason is simply because it would be natural to tenon the top rail, bottom rail (or meeting rails in the case of a sliding sash) and horizontal glazing bars all with the same shoulder length. Once a sash is glazed, the seal between glass and rebate will provide the strength.
It's a long established rule - sashes have glazing bars going through vertically, casements horizontally, in both cases to resist the forces opposing.
That's how they are all done, with good reason - bearing in mind that a trad sash with small panes will likely have very thin meeting rails - 18mm is common, with little stiffness unless tied to the top/bottom rail by the glazing bars.
 
Jacob":vik1ymm5 said:
There are no mullions, muntins or transoms anywhere in a sash window.
The glazing bars always go through vertically to resist the load of pulling them up and down. It makes for a very strong unit which means the timbers can be very slender, compared to a light with no glazing bars such as you might find in an Edwardian building.

So what then are mullions and muntins?
 
Mullions are the vertical structural elements which divide a window into separate "lights". Originally stone, but could also be wood. (Think of a 30s semi with several casements across the bay.)
The corresponding horizontal elements are transoms.

Muntins are the intermediate vertical elements in a framed and panelled door or screen or wall panel, parallel to the stiles, intersecting the rails.
 
Mullions I have found out are indeed the larger structural supports between window units.

Although muntins, sash bars and glazing bars are described as the thinner strips of wood separating the divided light panes in a sash window. No mention of transforms

Wikipedia - A muntin is a strip of wood or metal separating and holding panes of glass in a window.[1] Muntins are also called "muntin bars", "glazing bars", or "sash bars". Muntins can be found in doors, windows and furniture, typically in western styles of architecture. Muntins divide a single window sash or casement into a grid system of small panes of glass, called "lights" or "lites". In the UK and other countries, muntins (typically called "glazing bars" in the UK, or "astragals" in Scotland) :duno:
 
Transoms are as I stated earlier "An intermediate horizontal member of a frame" see Ellis at page 454 and Plate XXI or think of a 1930's casement window with a top hung casement then the transom is the piece of frame between the top and bottom casement. also a door frame with a top light then the piece of frame separating the door and top light is a transom.
 

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