Green Building Forum - Glazing bars Tue, 19 Dec 2023 05:51:11 +0000 http://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 Glazing bars http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15798&Focus=269337#Comment_269337 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15798&Focus=269337#Comment_269337 Fri, 13 Jul 2018 13:23:05 +0100 Silky
I noticed on some professional renovation projects that they have used glass dividing glazing bars. i.e. Windows are made up of several small panes joined with a sub-frame.

I've also now discovered while pricing that this style actually comes in cheaper for e.g. large window divided into 12 sections, in comparison to using 2 larger pieces of glass with the glazing bars glued on externally. Surprise to me.

I can think of another 2 advantages, in terms of ease of ease of installation there are only small pieces of glass to handle and a single piece of damaged glass would be considerably cheaper to replace in the future and there would be no problem of matching the finish of the glazing bars as they would not be changed.

Presumed disadvantage and why I never considered this option before was that the sub-frame would considerably impact the overall u-value of the window, in comparison to using a large piece of glass. Does anyone know if this is true?

And other realted tips?

edit : just adding a link to a picture of the ones I was looking at

https://3.bp.blogspot.com/-FRzj_VT3tcI/WzIETqZhV_I/AAAAAAAAD7E/0xxAyzXknugsJGOHR4eQAbQE7Q6t1paCACLcBGAs/s1600/Marktzentrum%2B%2B06.JPG]]> Glazing bars http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15798&Focus=269345#Comment_269345 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15798&Focus=269345#Comment_269345 Fri, 13 Jul 2018 20:54:24 +0100 djh Posted By: SilkyI've also now discovered while pricing that this style actually comes in cheaper for e.g. large window divided into 12 sections, in comparison to using 2 larger pieces of glass with the glazing bars glued on externally. Surprise to me.
That's a surprise to me too. More pieces implies more labour cost.

It will definitely be cheaper to replace a small pane than an entire window though.

Presumed disadvantage and why I never considered this option before was that the sub-frame would considerably impact the overall u-value of the window, in comparison to using a large piece of glass. Does anyone know if this is true?

Yes, I expect the sub-frame will make the U-value worse, and will be very surprised if anybody says it doesn't. It also reduces the solar gain of the overall window, by reducing the glazed area, which in most circumstances will be a disadvantage. Another disadvantage is the impact on the view - it's difficult to have a picture window with a lot of glazing bars!]]> Glazing bars http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15798&Focus=269352#Comment_269352 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15798&Focus=269352#Comment_269352 Sat, 14 Jul 2018 07:44:55 +0100 Peter_in_Hungary
In addition to the comments by djh above small glazing units as in Georgian windows or the ones shown in the OP are a pain to clean compare with large windows.

The reasons for the divided windows as shown in the renovation IMO will be the aesthetic look rather than price, although large windows as shown if they are a single units will have specific safety requirements not applicable to small units, which will add to the cost but I would not expect that cost to out weight the cost of the purpose made timber frames shown in the photo.]]>