Wooden double glazing - indiv panes or applied bars

jkgray

We have had a couple of different quotes for replacing our windows

One of the current windows so you can understand what I am talking about: http://i29.tinypic.com/29dbll3.jpg

Two window companies said that to achieve the Georgian bar look they would put in large double glazed units and then apply bars over the surface. They said that this was necessary rather than just re-create what is there now (lots of small panes) as (i) lots of small panes would be completely unaffordable; (ii) it would compromise the energy efficiency.

A recommended builder has quoted for replacing the windows as well as other works. He says he has obtained a quote from someone who manufacturers windows for the jobs he does. He will get the windows and the indivual double glazed units and insert the individual double glazed units into every pane on site. He is cheaper than the window companies. I mentioned the window companies stance to him. He said he has never had a problem so doesn't know what they are going on about.

Anyone any experience / comments in this area?

Thanks

:beer:

leveller2911

jkgray wrote: »

We have had a couple of different quotes for replacing our windows

One of the current windows so you can understand what I am talking about: http://i29.tinypic.com/29dbll3.jpg

Two window companies said that to achieve the Georgian bar look they would put in large double glazed units and then apply bars over the surface. They said that this was necessary rather than just re-create what is there now (lots of small panes) as (i) lots of small panes would be completely unaffordable; (ii) it would compromise the energy efficiency.

This is the method I use when making double glazed windows.With this system which is called Duplex.Its a good system and the plus points are : 1 buying a single larger unit is cheaper than buying 6 individual units.For instance if you buy a large unit that is 1000mm high x 500mm wide (0.5 square metre) you pay for 0.5 sq metre but if you buy 6 units say 300mmx200mm (0.06sq metre) you will be charged 0.3 sq metre for each unit.So it works out very expensive.


Another thing to consider is the glazing bars.If you have individual units the glazing bars need to be wider to accomadate the spacer bar(bar between the 2 panes of glass) and will be approx 36mm wide rather than 18-20mm wide.You can buy very thin units which will fit into traditional sashes but you will need to re-mortgage your house as they are rediculously expensive and to be honest they are a bit of a gimmick and I don't think the U value is low enough to comply with Building regulations so they tend to only be used in Grade 2 Listed properties.Make sure you clarify "Georgian bar" as this is not the correct system .Georgian bar is a white/brown bar that is fitted into the units instead of having glazing bars fitted both sides of the sash.You need a system called "Duplex".




A recommended builder has quoted for replacing the windows as well as other works. He says he has obtained a quote from someone who manufacturers windows for the jobs he does. He will get the windows and the indivual double glazed units and insert the individual double glazed units into every pane on site. He is cheaper than the window companies. I mentioned the window companies stance to him. He said he has never had a problem so doesn't know what they are going on about.

I don't think its a good idea having someone fit lots of small units on site.When you fit units you need to fit packers around the sealed units to stop the sashes from dropping out of square.Its much easier to fit units in the workshop where you can lay the sashes flat on a bench to glaze.The only times I fit units on site is when the window would be too heavy to lift with the glass fitted.I glaze all the sashes in the workshop and then just screw the sashes in place when the window frame is fixed.


Anyone any experience / comments in this area?

Thanks

:beer:

I would get at least one more quote and go with a small local Joinery workshop rather than the builder.There is no reason to glaze on site and what happends if they have rain showers on the days they want to fit them?, You can't fit units in wet/damp rebates but they probably would rather than get rained off for the day..It may be that the builders suppliers can't/don't glaze their windows and contract the work out to a glazing company..Its far from ideal IMO.One last thing don't have them made from Softwood(European Redwood) go for a decent hardwood like Sapele ,Iroko or Idigbo, but steer clear of Meranti hardwood as its no better than Softwood but companies charge a premium but its a poor hardwood.People do make softwood windows but unless they are pressure treated with preservative they won't last.Brushing on preservative or dipping is not good enough.

http://www.sashworks.co.uk/pdfs/dgwindows-tds.pdf

You can have any shape/style of glazing bar moulded.You can have ones made to match exactly your existing bars.

jkgray

Thanks for the info.

leveller2911 wrote: »

This is the method I use when making double glazed windows.With this system which is called Duplex.Its a good system and the plus points are : 1 buying a single larger unit is cheaper than buying 6 individual units.For instance if you buy a large unit that is 1000mm high x 500mm wide (0.5 square metre) you pay for 0.5 sq metre but if you buy 6 units say 300mmx200mm (0.06sq metre) you will be charged 0.3 sq metre for each unit.So it works out very expensive.

The two companies using large panes are both far more expensive than the smaller panes.

leveller2911 wrote: »

Another thing to consider is the glazing bars.If you have individual units the glazing bars need to be wider to accomadate the spacer bar(bar between the 2 panes of glass) and will be approx 36mm wide rather than 18-20mm wide.You can buy very thin units which will fit into traditional sashes but you will need to re-mortgage your house as they are rediculously expensive and to be honest they are a bit of a gimmick and I don't think the U value is low enough to comply with Building regulations so they tend to only be used in Grade 2 Listed properties.Make sure you clarify "Georgian bar" as this is not the correct system .Georgian bar is a white/brown bar that is fitted into the units instead of having glazing bars fitted both sides of the sash.You need a system called "Duplex".

This is my misuse of the term. The two using the larger panes would definitely be applying glazing bars to the outside and the inside of the pane. The "small pane" quote is obviously on the basis of actual solid bars all the way through and the small units inserted just as a single glazed piece of glass is now.

I'm not 100% the builder would glaze on site, he just mentioned about the panes being sealed into the frame with clear silicone when I asked about paint, putty ruining the new look of the glass/window.

leveller2911 wrote: »

I would get at least one more quote and go with a small local Joinery workshop rather than the builder.

The local joinery shop (large units) wants 50% more than the builder (small units). Both have quoted for "hardwood". The local joinery did also quote for soft wood but it was less than 10% difference in price.

Does any of this make any difference to your comments?

leveller2911

From my experience the Duples system always works out cheaper.Mainly due to be able to use a single larger unit.As I said if we used small units we would be charged a premium for the extra work involved in making each unit and also there is wastage on the glass.If the builder is usning "slimlite" units which are very thin indeed then I find that very strange as they are massively expensive.

I would try another Joinery workshop as they are either very expensive or the builder is too cheap... Can you post the quote? blank out any names/addresses etc ..You need to see the exact specification so that you can compare like for like.

Just an opinion here but I don't like glazing silicone.Its cheap ,it tends to ooze out over the glass and needs cleaning off and a good decorator will "cut in" his paint so that it just goes over onto the glass and seals the joint between the two.With glazing silicone you can't do this as paint won't stick to silicone.Ask the builder "How wide will the glazing bars be?" if the answer is about 35mm then they are standard units in wide glazing bars and look terrible and I would have alarm bells ringing if they were cheaper than single units with Duplex bars. If the glazing bars are say 18-20mm wide then they will be using slimlite type units which again would have alarm bells ringing as they are massively expensive.

Idealy go and have a look at previous work carried out by both suppliers as one may well be great quality and the other poor quality but you won't know unless you see their work. Or better still have someone recommeded by a friend /family.