How to make a sash window

Post by **jfc** » Thu Oct 02, 2008 8:23 pm

Well how i do it anyway .
I have a bay window to make that needs to comply with current building regs .so aswell as using spirals instead of sash weights i will also be buying in the gasketed parting bead and inserting brushes that run in a plastic carrier .
The end result will be something like this .

thallow · Post by **thallow** » Thu Oct 02, 2008 8:35 pm

So whats the secret to sitting & sealing double glazed units in a wooden frame?

daves · Post by **daves** » Thu Oct 02, 2008 8:46 pm

This should be interesting - enjoyed the last one

Dave

Post by **jfc** » Thu Oct 02, 2008 8:48 pm

Mastic

seanybaby · Post by **seanybaby** » Thu Oct 02, 2008 9:55 pm

jfc wrote:Mastic

That squeezy five finger shuffle?

Post by **jfc** » Thu Oct 02, 2008 10:10 pm

I fear you are mistaking mastic for another word beginning with mas

dom · Post by **dom** » Fri Oct 03, 2008 7:13 am

Massachusetts, masquerade, massive, mastoyd, master, Massif, masked ? Nope not getting it

Post by **jfc** » Fri Oct 03, 2008 11:58 am

First off i ran the grooves to take the spirals and parting bead , then mark out for the mortice and tenons and cut them .

sainty · Post by **sainty** » Fri Oct 03, 2008 4:01 pm

Nice work jfc.

What size sections are they?

rgds

Stu

Post by **jfc** » Fri Oct 03, 2008 6:33 pm

145mm x 32mm for the frames , cill 145mm x 45mm . The sashes are 65mm x 50mm and 95mm x 50mm for the bottom rails .

mrgrimsdale · Post by **mrgrimsdale** » Fri Oct 03, 2008 7:02 pm

I see they are running the same thread over there.
Nobody has mentioned trad sashes in either place. They are a lot different. Single glazed with 3mm glass the norm. Properly made are draught proof (enough) without needing brushes or seals of any sort. No need to panic abt building regs just ignore them, say it's repair not replacement, go on about conservation etc. If there is a prob offer to put in secondary glazing.
BTW, DG is rarely worth the expense. Work out the heat loss calculations for yourself if you doubt this. It's about the least cost effective thing you can do to reduce your bills. All the other things are a better idea; insulation, condensing boilers etc.
One of the big advantages of trad windows (which goes largely unrecognised), is the de-humidifying function. Condensation runs down the glass and out through the gaps at meeting rails or cills.

cheers
Jacob

tusses · Post by **tusses** » Fri Oct 03, 2008 7:47 pm

mrgrimsdale wrote: One of the big advantages of trad windows (which goes largely unrecognised), is the de-humidifying function. Condensation runs down the glass and out through the gaps at meeting rails or cills.

cheers
Jacob

;D

I always remember Tommy saying that !

;D

mrgrimsdale · Post by **mrgrimsdale** » Fri Oct 03, 2008 8:02 pm

tusses wrote:
mrgrimsdale wrote: One of the big advantages of trad windows (which goes largely unrecognised), is the de-humidifying function. Condensation runs down the glass and out through the gaps at meeting rails or cills.

cheers
Jacob
;D

I always remember Tommy saying that !

;D

Tommy Walsh? Was me that explained it to him (amongst other things)!

cheers
Jacob

engineerone · Post by **engineerone** » Fri Oct 03, 2008 8:06 pm

for once i agree with jacob :-[

in the flats in which i live we have central heating, but no
dg, and i have never had any problems with condensation or
mould etc growing, because unlike some of my neighbours i have
not blocked off the air bricks, or close off the air movement gaps.

those guys who designed houses for coal fire really understood things quite well. proper air movement it important.

paul

Post by **jfc** » Fri Oct 03, 2008 8:09 pm

There is quite a heavy fine for not complying with regs , i think it is about 10 K .

sainty · Post by **sainty** » Fri Oct 03, 2008 8:36 pm

mrgrimsdale wrote: BTW, DG is rarely worth the expense. Work out the heat loss calculations for yourself if you doubt this. It's about the least cost effective thing you can do to reduce your bills. All the other things are a better idea; insulation, condensing boilers etc.

cheers
Jacob

I was reading an article the other day that had DG as 9th in a list of 10 things to make your house more energy efficient. Eliminating drafts was high up the list though.

rgds

Stu

mrgrimsdale · Post by **mrgrimsdale** » Fri Oct 03, 2008 8:52 pm

engineerone wrote:for once i agree with jacob :-[
snip

Seem to hear that a lot - people being surprised to find that they agree with me.
Must be the way I say it or something!

cheers
Jacob

mrgrimsdale · Post by **mrgrimsdale** » Fri Oct 03, 2008 8:55 pm

sainty wrote:
mrgrimsdale wrote: BTW, DG is rarely worth the expense. Work out the heat loss calculations for yourself if you doubt this. It's about the least cost effective thing you can do to reduce your bills. All the other things are a better idea; insulation, condensing boilers etc.

cheers
Jacob
I was reading an article the other day that had DG as 9th in a list of 10 things to make your house more energy efficient. Eliminating drafts was high up the list though.

rgds

Stu

Draft elimination amongst the cheapest and most effective, DG the most expensive and least effective. Depending on circumstances of course.

cheers
Jacob

Post by **jfc** » Fri Oct 03, 2008 9:04 pm

Still doesnt get away from the fact that if you replace your windows you HAVE to fit double glazing to comply with building regulations . You may get away with not doing it but it will get picked up when you try to sell your house and the fitter will be getting a phone call asking why these windows are holding up the sale of a customers house .

jake · Post by **jake** » Fri Oct 03, 2008 9:10 pm

sainty wrote:I was reading an article the other day that had DG as 9th in a list of 10 things to make your house more energy efficient.

I'll bet those stats assume you are replacing servicable single-glazed windows with new replacement double-glazed windows *just* for the extra energy efficiency,which is a bit of a red herring where the windows need replacing anyway, and the incremental cost of the DG units is really quite small.

Not that I want to pop Jacob's carefully rationalised self-justification for killing the planet, man.

modernist · Post by **modernist** » Fri Oct 03, 2008 9:52 pm

Just to illustrate the pitfalls here is my triple glazed, argon filled (or was) K glass 0.28w/m2 patio door after less tha a year. I hope the warranty holds on the glass

First morning at 4 deg C

happy days

at least I'll be able to get the beads out with my pre-prepared levering groove a la german practice

cheers

Brian

jake · Post by **jake** » Fri Oct 03, 2008 10:00 pm

Woah, wtf happened there?

mrgrimsdale · Post by **mrgrimsdale** » Fri Oct 03, 2008 10:52 pm

jake wrote:
sainty wrote:I was reading an article the other day that had DG as 9th in a list of 10 things to make your house more energy efficient.
I'll bet those stats assume you are replacing servicable single-glazed windows with new replacement double-glazed windows *just* for the extra energy efficiency,which is a bit of a red herring where the windows need replacing anyway, and the incremental cost of the DG units is really quite small.

Not that I want to pop Jacob's carefully rationalised self-justification for killing the planet, man.

Brian got there before me! If you factor in obsolescence its a different picture - DG units last 10/20 years, trad sashes last 100/200 years.
It's a no brainer, you hardly need to do the sums. DG is an environmental fiasco as are a lot of other highly obsolescent modern building practices and materials, mdf, plastic, misused hardwoods from non sustainable sources etc. etc .
Those big windows I'm doing would still be in perfect condition if they had been painted just 2 or 3 times in the last 50 years. With linseed oil pints of course - anything else the kiss of death. Am re-using the 130 year old glass so that could have a life span of 2 to 3 hundred years. DG glass is scrapped at 20 max.

cheers
Jacob

Post by **jfc** » Fri Oct 03, 2008 11:04 pm

I intend on putting DG in my house because my single glazed windows are like open fridge doors in the winter . The fact that my new windows have been sat in my garden for the last ten years is another matter :-[

engineerone · Post by **engineerone** » Sat Oct 04, 2008 12:01 am

excuse me since when did 10 years old get to be new ???

is this jacob mathematics ;D

paul

mrgrimsdale · Post by **mrgrimsdale** » Sat Oct 04, 2008 7:27 am

jfc wrote:I intend on putting DG in my house because my single glazed windows are like open fridge doors in the winter . The fact that my new windows have been sat in my garden for the last ten years is another matter :-[

Sorry Jason we seem to have gone off at a tangent and hijacked your thread talking about environmental issues.

What about having another section for trad woodwork - I'm not the only one fiddling about with old bits of junk and trying to copy them? Trad building and green issues also go together.

cheers
Jacob

Post by **jfc** » Sat Oct 04, 2008 8:55 am

Good idea . I just need to work out how to move the posts ::) :-[

mrgrimsdale · Post by **mrgrimsdale** » Sat Oct 04, 2008 9:01 am

jfc wrote:Good idea . I just need to work out how to move the posts ::) :-[

We can do it ourselves by copying and pasting. No Prob

jake · Post by **jake** » Sat Oct 04, 2008 12:04 pm

mrgrimsdale wrote:Brian got there before me! If you factor in obsolescence its a different picture - DG units last 10/20 years, trad sashes last 100/200 years.
It's a no brainer, you hardly need to do the sums.

But the stats you were quoting must be based on full replacement, so are totally misleading in terms of payback time.

That kind of catastrophic failure ^^ must be very rare. So you are really dealing with misting up problems - no reason in theory why the units can't be split and remade, with minimal enviro impact (whether that's ever done in practice is another question).

I've got hideous late 70s/early 80s aluminium windows some previous idiot installed on our frontage - no problems with them at all (apart from their total hideosity) and they must be getting nearer to 30 years old.

No doubt the whole uPvC/replacement for replacements sake is nonsense, but if the window is beyond repair (or it's a new opening), and the window frames/sashes need replacement anyway...

modernist · Post by **modernist** » Sat Oct 04, 2008 1:41 pm

jake wrote:Woah, wtf happened there?

Good question! it only did that one the one morning. Must have been unusual weather but clearly the seal has gone.

The problem is this is a 5m x 4m glass wall with the patio door in the middle. We are 1000ft up and completely exposed to the point that the trees lean over 20 deg and the building inspectorate forbade the use of cavity wall foam on the grounds that the horizontal rain will be "running down the inside of the cavities" and therefore needed air to breathe (Bet you like that Jacob!)

Every cloud - it will give me the opportunity to put the drain holes in the bottom rail that I forgot in the rush to get the glass in put the grooved beads to the test

I'll let you know how I get on

Brian

mrgrimsdale · Post by **mrgrimsdale** » Sat Oct 04, 2008 3:14 pm

modernist wrote: snip
Must have been unusual weather but clearly the seal has gone.
snip

Sad fact of life this but a lot of people with failed DG units put it down to special circumstances or bad luck. In fact it's extremely common. I don't really know what the failure rate in say 5 years would be, but wouldn't be surprised if it was 50% ish.
One year not uncommon. Sometimes the whole batch - and the supplier has done a runner

cheers
Jacob

tusses · Post by **tusses** » Sat Oct 04, 2008 8:27 pm

engineerone wrote:excuse me since when did 10 years old get to be new ???

is this jacob mathematics ;D

paul

well my house is 200 yrs old

so my misted up 10 yr old double gazing could be considered new ? ! and needs replacing. I am very tempted to go back to original !!! it would look a whole lot better for start !

telos · Post by **telos** » Sun Oct 05, 2008 11:30 am

modernist wrote:... it will give me the opportunity to put the drain holes in the bottom rail that I forgot in the rush to get the glass in put the grooved beads to the test...

What exactly have you used to seal the glass in place? I can't make out any mastic or rubber seal in your first photo.... and if you haven't left any air circulation gap around the entire DG panel and/or drain holes at the bottom of the frame or bead, then that is the reason your glass has failed...

modernist · Post by **modernist** » Sun Oct 05, 2008 6:51 pm

What exactly have you used to seal the glass in place? I can't make out any mastic or rubber seal in your first photo.... and if you haven't left any air circulation gap around the entire DG panel and/or drain holes at the bottom of the frame or bead, then that is the reason your glass has failed...

There is an air gap all round and the pane is standing on glazing blocks. I sealed the outside only with low mod silicone and left the inner beads dry.

What do you think?

Brian

Post by **jfc** » Sun Oct 05, 2008 6:55 pm

Whats the point of leaving an air gap around a sealed unit ???

telos · Post by **telos** » Mon Oct 06, 2008 9:15 am

modernist wrote:
What exactly have you used to seal the glass in place? I can't make out any mastic or rubber seal in your first photo.... and if you haven't left any air circulation gap around the entire DG panel and/or drain holes at the bottom of the frame or bead, then that is the reason your glass has failed...
There is an air gap all round and the pane is standing on glazing blocks. I sealed the outside only with low mod silicone and left the inner beads dry.

What do you think?

Brian

??? Sounds perfect to me. You must have been very unlucky and received a duff unit. If the only thing you are missing are vent holes, the unit shouldn't have failed in less than a year.

Still, it must be covered by the manufacturer guarantee? Or did you fit it yourself.... In which case begging and grovelling might be required.

Just, re-read your post, the inner beads are sealed to the glass with dry rubber seals, yes? If you left them completely open to the air inside your house, then the moisture in the air will be condensing on the sides of your DG unit, which is "not a good thing". The frame must be sealed to the glass all round, inside and out, with external venting at the bottom.

telos · Post by **telos** » Mon Oct 06, 2008 9:20 am

jfc wrote:Whats the point of leaving an air gap around a sealed unit ???

It is essential for the longevity of the DG Unit. Contact with the frame must be avoided completely, which is why the plastic blocks are used. They also have a secondary, but vital function, of allowing air to circulate around the unit to equalize air pressure and vent any moisture that should sneak behind the seals to escape to the outside.

Units that are not correctly installed may last 10 years if you're lucky, or 6 months if you're not.

Post by **jfc** » Mon Oct 06, 2008 9:56 am

I understand the no contact with the frame but why not fill the gap with mastic , other than its a waste of mastic .

telos · Post by **telos** » Mon Oct 06, 2008 10:51 am

jfc wrote:I understand the no contact with the frame but why not fill the gap with mastic , other than its a waste of mastic .

Read on young Padwan...

Telos wrote:... They also have a secondary, but vital function, of allowing air to circulate around the unit to equalize air pressure and vent any moisture that should sneak behind the seals to escape to the outside....

No air gap (including equalized air pressure) = potential DG unit seal failure

Post by **jfc** » Mon Oct 06, 2008 11:03 am

My point is if the gap is filled with mastic there will be no moisture . As for equalizing air pressure , its a window not a space ship ;D