Chaps,
First post here (I've just signed up), so please be gentle!
I'm making some sash windows for our house. It's a Georgian terrace in East London, and the existing sash windows are pretty old and some of them rotten. I've made sash windows before with good results - I've made the sashes from pine, painted them, had some glass cut to fit and stuck it in with putty then put the sashes in the frames.
However this time I want to make them from hardwood and double-glaze them. And this looks a fair bit more complex. I have done some searching on here (and elsewhere) and discovered a number of things I hadn't anticipated - and which make things rather more complex than just using single-paned glass.
1. You can't use putty to hold the units in, you need to use special tape, like this:
http://www.indigo.co/ecom-catshow/double-sided-foam-tape.html
Not a problem, presumably I just buy some!
2. You need to use glazing blocks. I can find a diagram of how to position these, but have no idea of what they are or why I need to use them.
If I look them up on google images I get pictures of little rectangles of colour, and nothing much else. I am guessing that they are something that allows a certain amount of movement in the frame without exerting (much) force on the glazing unit - a kind of cushion between the two, but this doesn't make much sense as surely the frame tape does this? Is my guess right, or am I way wide of the mark?
3. Looking at this picture:
(Where you are looking at a cross-section of the frame channel, with the glazing unit in it, and red stuff is frame tape and green stuff is silicone sealant)
... it has a picture of an outside bit of trim that attaches to the window frame, in the rebate that the glazing unit occupies, holding the glazing unit in. Is this essential? I am assuming it will need to be made of the same hardwood that the sashes will be made of, and painted before installation? And how do I hold it in - small screws or tacks?
It appears that common thicknesses for the glazing units are 18mm, or more. Therefore, a bit of simple maths:
Depth of rebate for glazing unit = thickness of glazing unit (18mm) + thickness of two layers of glazing tape (2x2mm = 4mm) + thickness of outside trim (5mm? More?) = at least 27mm.
This means that the rebate I cut into the wood to take the glazing units needs to be at least 27mm deep - non? And preferably a bit more (5mm for the outside trim seems a bit thin to me - it's likely to be more if I am to make it without breaking it.)
That's a pretty deep cut. 3cm. The sashes are only going to be 3.5cm thick, so that's leaving a 5mm bit of wood for the whole lot to mount on. Have I really got this right?
Another couple of questions:
- I am confidently assuming that I can go into a double-glazing shop and buy double-glazing units to the size I want (in much the same way as I can go into my local glass shop and buy glass in any size I want.) Is this so? if I take my newly-made sashes into a shop they will make up double-glazing panels to fit them? What sort of shop should I go to to have this done? Also, how much is this likely to cost? I reckon on about £10-15 to have a 'normal' sash glazed (depending on how big it is) - I am assuming that DG units will come to well over double this cost?
- DG units will be heavier than the single-glazed units which I am removing, and hence I will have to re-weight the sash counterweight system. How do I do this? Do I buy bigger weights, or try sticking something heavy to the existing weights?
- What can I do to draught-proof the windows? I will make them to fit the frames as tightly as I can, but does anyone have any experience (good or bad) of draught-proofing systems for this sort of thing? Either the furry strips you stick along the side, or something more substantial? I currently tape our windows shut during the colder months of the year (they leak air like there is no tomorrow), and I am hoping to get 'round this.
I realise this is quite a long first post, so thanks for reading this far.
All help greatly welcomed. Many thanks in advance.
Oli.
[/img]
First post here (I've just signed up), so please be gentle!
I'm making some sash windows for our house. It's a Georgian terrace in East London, and the existing sash windows are pretty old and some of them rotten. I've made sash windows before with good results - I've made the sashes from pine, painted them, had some glass cut to fit and stuck it in with putty then put the sashes in the frames.
However this time I want to make them from hardwood and double-glaze them. And this looks a fair bit more complex. I have done some searching on here (and elsewhere) and discovered a number of things I hadn't anticipated - and which make things rather more complex than just using single-paned glass.
1. You can't use putty to hold the units in, you need to use special tape, like this:
http://www.indigo.co/ecom-catshow/double-sided-foam-tape.html
Not a problem, presumably I just buy some!
2. You need to use glazing blocks. I can find a diagram of how to position these, but have no idea of what they are or why I need to use them.
If I look them up on google images I get pictures of little rectangles of colour, and nothing much else. I am guessing that they are something that allows a certain amount of movement in the frame without exerting (much) force on the glazing unit - a kind of cushion between the two, but this doesn't make much sense as surely the frame tape does this? Is my guess right, or am I way wide of the mark?
3. Looking at this picture:
(Where you are looking at a cross-section of the frame channel, with the glazing unit in it, and red stuff is frame tape and green stuff is silicone sealant)
... it has a picture of an outside bit of trim that attaches to the window frame, in the rebate that the glazing unit occupies, holding the glazing unit in. Is this essential? I am assuming it will need to be made of the same hardwood that the sashes will be made of, and painted before installation? And how do I hold it in - small screws or tacks?
It appears that common thicknesses for the glazing units are 18mm, or more. Therefore, a bit of simple maths:
Depth of rebate for glazing unit = thickness of glazing unit (18mm) + thickness of two layers of glazing tape (2x2mm = 4mm) + thickness of outside trim (5mm? More?) = at least 27mm.
This means that the rebate I cut into the wood to take the glazing units needs to be at least 27mm deep - non? And preferably a bit more (5mm for the outside trim seems a bit thin to me - it's likely to be more if I am to make it without breaking it.)
That's a pretty deep cut. 3cm. The sashes are only going to be 3.5cm thick, so that's leaving a 5mm bit of wood for the whole lot to mount on. Have I really got this right?
Another couple of questions:
- I am confidently assuming that I can go into a double-glazing shop and buy double-glazing units to the size I want (in much the same way as I can go into my local glass shop and buy glass in any size I want.) Is this so? if I take my newly-made sashes into a shop they will make up double-glazing panels to fit them? What sort of shop should I go to to have this done? Also, how much is this likely to cost? I reckon on about £10-15 to have a 'normal' sash glazed (depending on how big it is) - I am assuming that DG units will come to well over double this cost?
- DG units will be heavier than the single-glazed units which I am removing, and hence I will have to re-weight the sash counterweight system. How do I do this? Do I buy bigger weights, or try sticking something heavy to the existing weights?
- What can I do to draught-proof the windows? I will make them to fit the frames as tightly as I can, but does anyone have any experience (good or bad) of draught-proofing systems for this sort of thing? Either the furry strips you stick along the side, or something more substantial? I currently tape our windows shut during the colder months of the year (they leak air like there is no tomorrow), and I am hoping to get 'round this.
I realise this is quite a long first post, so thanks for reading this far.
All help greatly welcomed. Many thanks in advance.
Oli.
[/img]
