Double glazing advice wtd, any window fitters on here?

We’re looking to get some for our house, had a few quotes and have been overwhelmed with info and blinded by science with some of the blurb to be honest.

From what I can tell the windows units are either 20mm or 28mm with thinner glass, reflective coating etc etc if I’m correct.
Wondered which is best or much the same?

Any other forums where I could ask?

Thanks in advance

Only advice I can give you is don’t go for anyhibg from the Anglian group, having worked for them I know thier products to be tosh and thief staff to be liars.

low e coated and argon filled as a minimum. Not sure if they do warm edge bars in pvc too.

theres a new reg out now/soon IIRC that mandates a max U-value too.

argon filled as a minimum

really …I thought / read (on the internet so must be true!) that it just leaked out after a couple of years..is that not true ?

28mm is the standard now IIRC

part L regs have just changed, is this an extension? refurb etc? It matters.

there are pros and cons of hard coat and soft coat glasses and the way they perform with regards to solar gain and internal heat loss.

Argon filled, nitrogen filled, it’s all just a con. There is no measurable difference in insulation.
28mm units are pretty much standard now too.

To be honest, any midrange product will be fine. Even the cheapest ones are there days are better than the absolute best 8-10 years ago.
Just get decent locks, not because you’ll get broken into, but because they won’t break.
If you’re going for doors too, i’d go for a composite over plastic, ie rockdoor. I’ve fitted loads this year, they look much nicer and feel much more solid than plastic.

The installation is the most important part

Argon wont leak out except over very very long periods unless the unit was poorly constructed.

If the gas did leak out then obviously air (carrying water vapour) would have replaced it and you’d see condensation in certain weather conditions.

Argon filled, nitrogen filled, it’s all just a con

says you then.

So why on earth would it be such common practice then?

A more practical alternative is to replace air in the space with a heavy gas that is more viscous than oxygen and nitrogen. Higher viscosity reduces convective heat transfer. Argon (argon has a thermal conductivity 67% that of air)[20], krypton (krypton has about half the conductivity of argon) or xenon to increase the insulating performance. These gases are used because they are non-toxic, clear, odorless, chemically inert, and commercially available because of their widespread application in industry. These gases have a higher density compared to air but have higher costs. In general, the more effective a fill gas is at its optimum thickness, the thinner the optimum thickness is. For example, the optimum thickness for krypton is lower than for argon, and lower for argon than for air.[21] However, since it is difficult to determine whether the gas in an IGU has become mixed with air at time of manufacture (or becomes mixed with air once installed), many designers prefer to use thicker gaps than would be optimum for the fill gas if it were pure. Argon is commonly used in insulated glazing as it is the most affordable. Krypton, which is considerably more expensive, is not generally used except to produce very thin double glazing units or relatively thin, or extremely high performance triple glazed units.[22] Xenon has found very little application in IGUs because of cost.[23]

composite doors are better than wood or upvc panels, but, stick with white if you have a south facing door.

Stoner, i’m well aware of the different properties of the nobel gases. However, as a wrote, there is no measurable difference in any practical application.

@TheFunkyMonkey.
Interesting you mention Rockdoor. I’m thinking of getting one fitted. Any idea of the cost of one fitted? One like this one but with only one side panel.

from the figures Ive seen there’s a 10% fall in U-value for an Argon fill compared to without.

Dunno about door construction but make sure you spec door lock barrels that are anti-bump and snap safe and if you want belt and braces stick on a door handle that is PAS 24 spec.

That way you should avoid any middle of the night stealth raids where you get your car keys nicked. Any other method of entry usually involves some noise or disruption that proper crims would rather avoid.

Plop, depends on your supplier as they will most likely make up the side light. I’d guess around 900ish supply and probably 120 to fit.

go for the 28mm units, for thermal insualtion the pvc windows are best in my honest opinion as ali windows still get cold spots. Company’s try to flaunt the “argon Filled” as a sales pitch but its pretty standard these days every unit i fit has the stuff in it…

depending what company you go with will depend on the quality of the windows/locks they use. ask them to tell you the name of the system if its duraflex just avoid it. its cheap and nasty stuff. Rehau and system 10 are better quality as are plenty others.

With doors as above state the Composite doors now outclass any pvc/timber door they are brilliantly secure and look brilliant for a very long time.

Recently fitted a whole block of flats for local council with composite doors and there was a police raid on a property there. They spent over 45 minutes trying to get into 1 of the doors we had fitted then gave up and smashed through a side window instead was very funny to watch them 😆

Interesting you mention Rockdoor. I’m thinking of getting one fitted. Any idea of the cost of one fitted? One like this one but with only one side panel.

I could tell you the trade price, and it isn’t pretty. The price difference between what i sell at and the price you buy at is huge.

Argon filled is pretty much standard in commercial glazing. Argon will leak from polysuphide sealed units, but will stay in silicone sealed units.

FunkyMonkey – Argon typically drops the centre pane u-value of the unit by approx 0.5W/msqK which is a pretty big percentage drop.

As said above, a low E coating is required under building regs, but don’t go for Pilkington K whatever anyone tells you. It’s not as good as other coatings performance wise, and has a brown tint/colour to it.

Don’t pay more than £5/sqm for argon filling. Warm edge spacers will make little to no noticeable difference, so aren’t really worth the extra, especially in a uPVC window.

I can’t think of a single pro for a hard coating on the glass over a soft coating. Soft coats perform better, but are typically more expensive. Hard coats are old technology.

There are a LOT of different coatings you could get depending on what you want from your windows (looks, perfomance etc), but i’d just get a decent low e coated unit with a 16mm cavity (optimum for lowest heat loss with argon gas filling).

A laminate glass will help add an element of security to the glass, but if a crim knows what he’s doing, will still get through.

I can’t think of a single pro for a hard coating on the glass over a soft coating. Soft coats perform better, but are typically more expensive. Hard coats are old technology.

depends on the sun as to which is the better choice, look around and there is alot of technical info on which products do what best

Cheers for feedback.

It’s just replacing our sash windows, bit of a crime as we’re the last in the terrace to do so. I’ve been putting it off for ages as I like the the originals but north east facing and winter coming…….

Tony24 i think the 28mm units are duraflex and they were about the cheapest IIRC, so really not worth going with them then?

One of the other companies uses Rehau but pretty sure they were 20mm units, do they do 28mm?

The other companies are using Tricept & Deceuninck windows any feedback on either of these anyone? Both of these were 20mm units I think.

Hadn’t thought about the locks but will look into that as well.

Any more recommendations keep them coming cheers 😀

http://www.premdor.co.uk/premdor-p-products.asp?categoryID=3&subcategoryID=15

depends on the sun as to which is the better choice, look around and there is alot of technical info on which products do what best

In what way will the sun effect the performance?

I do tell a lie though. I have thought of two pro’s on hard coat over soft coats:
1. Some hard coats can be used on the outside of the unit rather than in the cavity
2. Hard coats are easier to store, handle and manufacture into unit

Neither of which would be helpful to the OP.

Should have said that kind of limited budget and replacing the sash windows for casement as sliding sash would be twice the price but at least we’ll be keeping the wood architrave inside so keeping some character.

we do casement windows too – here’s our full range: http://www.premdor.co.uk/premdor-p-products.asp?categoryID=3

only downside (if it is one) is that, being timber, they need painting once every 10 years or so

get down to your local Magnet, Jewson or Wickes to have a look at the quality

slackman the materials used tend to respond differently to radiation, i can’t remember which way round it goes, but basically one is better at radiating heat into a room and the other at reflecting sunlight back so lowering the solar gain.

As for rehau and 28mm, we sell shed loads of 28mm upvc panels to rehau installers, to be honest almost no one buys anything by 28mm upvc panels, i would be very surprised if there was no rehau window system that could take a 28mm panel. Most of these are for UPVC doors but some are used in glazing contexts.

mrmo, the soft coats we deal with at work typically help reduce the solar gain (for others, not mrmo, reducing the sun heating a room like a greenhouse)while still having a lower u-value and thus keeping more heat in the room (by reflecting the heat from the room back into itself). Unless you were talking about radiating heat into the room by absorption into the glass material itself and it acting like a radiator?

All I can say is minimum for compliance with Part L and N will be fine but also get some that are SBD compliant. Check with your home insurance too with what they ask for. Most importantly though make sure they’re installed correctly

mrmo – intrigued about your comment re: white kit on south facing properties ? I’ve suffered warped frames with a dark finish with the net result of big gaps between the frame and window unit. Presumably this is a known problem with dark units/frames ?

I’m not quite sure what coating was mentioned on some of the quotes, think it might have been internal heat reflective? I’ll have to check.

should have said reflecting heat back not radiating heat back.

done a bit of googling, soft coat tend to have better U values than hard coat, but hard coat tend to allow more solar energy through.

So the logic is where there is direct sunlight you don’t want to much transmittance as you cook so use a soft coat, but on other building faces it may make more sense to use a hard coat to maximise the solar transmitance and make the most of the solar gain, but with a slightly lower u value.

The difference in the real world of 3 bed semis, doubtful.

As above, safety glass in doors and anything below 800mm high (so side lights to doors). Toughened glass or laminates are fine as a safety glass. Toughened is more difficult to break. Laminate is more difficult to get through once broken.

I’m not up to speed with the new doc L for refurb dwellings, but I believe that the whole window needs to be a WER (window energy rating) band C or better (which the installer should be able to tell you). It used to be that as long as the glazing provided a centre pane u-value of 1.1 or better then that was sufficient, but the new doc L (came into effect this month) changed that.

Fairly suprised to see Premdoor recommended as a premium product: Have fitted a few of their doors over the years and I must say that for the money I was not too impressed with 6mm ply being used for the panels on external doors, nor veneered MDF fielded panels on external doors, nor pencil thin dowels used instead of proper mortice and tenon joints.
Maybe they’ve got better in the last while???

allthepies, if installed well the dark finishes should be ok, but they are more intolerant of poor workmanship and manufacturing flaws. Not trying to insult anyone on here who may be in the building industry there are some real cowboys out there and it does show. I see the warranty claims and certain companies lodge disproportionally more claims than others.

Well pretty much all the windows in my house have gaps due to warping of the *dark* frames. Of course the supplier went bust a couple of years back so no comeback. Are my only choices a) live with it. b) replace frames (with what?) and keep window units c) bin the lot and start over ?

mrmo at work on south facing elevation we typically install a soft coat solar control to prevent too much heat build up in the building.

On north facing elevations we install a soft coat low e which have better u-values than their hard coat counterparts and light transmittances than the solar control glasses.

But, as you say, in a 3 bed semi, you would be very hard pushed to tell. In a glazed office block or school, it’s another matter.

Sliding sash windows aren’t great on u-values in anyways, so i’d just go with a decent low e glass, and the band c rating.

Have fitted a few of their doors over the years and I must say that for the money I was not too impressed with 6mm ply being used for the panels on external doors, nor veneered MDF fielded panels on external doors, nor pencil thin dowels used instead of proper mortice and tenon joints.
Maybe they’ve got better in the last while???

I’m not “recommending” them, I work for them. But I dunno, I’ve only worked in the IT department since 2000.
And there’s only one “o” in Premdor

granny_ring the duraflex system comes in cheapest because thats what it is cheap crap generally has no reinforcing and is made as cheap as possible. Rehau system is a safe bet they are a good quality window and the plastic does not discolour quickly and they look good for many years. rehau do a 28mm system for sure i fit it near enough day in day out. providing you get it supplied from a company who know what they are doing it will be of good quality.

Well you should have said you were replacing sashes. just put new pvc sashes in, you’ll need to mess about a bit with infilling where the boxes have been, but these will give the look and reasonable performance thermally. I have a load of them in my house, they’ve been in five years and haven’t had a problem with them.

http://www.quickslide.co.uk/%5B/url%5D

Thanks again all for info, very helpful.

I’ve got to get back to the companies for more detail on some of the window and glass specs & coatings etc.

tony24, yep had another look and 2 of the quotes I’ve had use Rehau and are 28mm units. Both local companies, one makes up the frames and the others are made somewhere else. One or both use K glass, not sure if any other is used?

midlifecrashes, had a look at their site, looks interesting. If I go down the supply only route will give them a shout too.

John, they’re going to be upvc for the ease of maintenance thanks.

Anyone heard of or used Tricept windows?

Cheers

No problem; mine arw PVCu despite me working for a timber door/window company 😉