Currently live in a 1930’s property that has 15-20yr old upvc double glazed windows which appear to be fairly rubbish (lots of condensation issues)

so been thinking of replacing our current windows, have a general dislike for upvc windows so was thinking timber frames and triple glazed panes, does this seem sensible or am i going to cause more issues? do i need trickle vents?

look forward to any comments / suggestions

I don’t see the point of triple glazing in the UK climate, let alone an older house. Having had serious condensation/mould issues in a 1930s house (with double glazing and cavity wall insulation) for years, I put a positive pressure/input ventilation unit in about a month ago and all the problems are gone. Bloody miracle and only cost £200!

interesting, what system have you installed as a quick look into these seems that its going to cost more than £200?

If the condensation problems are in the windows, then the sealed units are no longer sealed. If the condensation problems are in the rest of the house, then replacement windows won’t solve those problems.

Unless I had a lot of glazed area and were chasing a particular level of certification or I had soundproofing needs I’d probably not bother with triple glazing. The price increase over double glazing does not give you an incremental improvement. It’s diminishing returns.

One of these: http://shop.dryhomes.net/products/drimaster-standard

Just requires cutting a hole in the ceiling and wiring to the live/neutral of the loft lighting circuit.

I think I’m actually more thrilled with it than my Banshee Spitfire that I’m always raving about…

Yes, if it’s ‘blown’ panes in the glazing then that’s another issue entirely.

thanks for that chief!

existing double glazed units are fine, think we’ve got a general ventilation issue

The insulation (u) value between the best 2g and 3G isn’t that great. A bigger impact is likely to be the frame and the quality of the fitting. The Main advantage or 3G is the increase in the temperature of the inner pane means you can sit closer to the glass without feeling cool so you effectively gain interior space.

At least that’s the theory. I’ll let you know hoe it goes in a year.

The difference between some double glazed windows we had installed last year and the existing double glazed windows that are ~15 years old is massive. The old units are fine, but I guess the general efficiency and quality of the newer units is much better to the point that I’m tempted to get the older ones replaced even though they are technically fine…

Chief next time I see you please talk to me about the positive pressure thing. We have a condensation problem in one room. Upstairs bedroom wall runs with water when it’s cold out. Incidentally we just had new triple glazing put in. It’s great and wasn’t much more expensive than double. Our old windows used to get steamed up but now they are so well insulated I think the moist air is finding the coldest place to condense which is the wall.

If you are getting new windows then I would suggest getting trickle vents anyway. Gives you the option of leaving the vents open to get some air through. Especially handy in bathrooms etc. Our old 1970’s bungalow had no trickle vents. We constantly had mould around the house. We couldn’t fit trickle vents to those windows as because of the frame shape.

Fortunately our new house has trickle vents. No mould problems and nice and toasty warm.

Wooden frames will make far more difference than triple over double glazing. UPVC is rubbish as heat insulation

Ventilation is good thing especially if it includes heat recovery.

Having had triple glazing for a couple of years I wouldn’t go back to double even on south-facing walls. Arguments such as the loss of solar gain being greater than heat saved just don’t stack up in December and January. As Simon hopes, there really are no cold spots in the room and a chair Madame avoided is now her favourite.

Another advantage is that triple glazed frames are usually 2cm deeper which allows insulating right up to the frame if you are insulating the walls on the inside too. We used to get more condensation on the wall around the frames of the double gazed windows where there was a thermal bridge than on the glass. Not any more.

Wooden frames will make far more difference than triple over double glazing. UPVC is rubbish as heat insulation

Is that right? Doesn’t the air gap in the extrusion act as an insulator?
would like to know if that’s right as it might influence what type of windows I get.

What sort of price are you looking at for a triple glazed? All ours are shot too.
Mostly small cottage windows 1m sq

UPVC is rubbish as heat insulation

That is incorrect. The UPVC frames are honeycomb/labyrinth structures with more air than UPVC and beat any wooden or aluminum frames available when I was doing my research. You need to look at the uW figure, that’s the value for the whole window and frame. You’ll find the best figures are for UPVC frames and triple glazed glass with various heat reflecting treatments.

Trickle vents are just ventilation with no heat recovery. It’s more energy efficient to have no vents in the windows or walls but an efficient ventilation system with heat recovery.

Considered triple glazing for our new bay window and porch extension, bought all the windows direct from the manufacturer. I asked him for the pros and cons, he said don’t bother for the heat loss side but do for sound. He only has double on his house. New double glazing is much better than that of 10/15 years ago and the fitting is important, a lot of heat is lost in those areas that the installers cover with the plastic trims. I fitted my own and it has made a massive difference.

I went for triple glazed when I put bi-folds into my kitchen. I was concerned about heat-loss because we spend most of our time in the kitchen & the Aga has always kept it nicely warm. I’m really glad I did, even in the current freezing weather we’re perfectly fine around the table sitting just a few inches away from the glass. The triple glazing only cost 5% extra.

As others have said, the frames make a big difference, not much point paying for 3G unless the frames are properly insulated. I bored everyone to death researching the options before spending the cash- not all manufacturers are keen to publish the u-values of the frames, they just concentrate on the glass.

a lot of heat is lost in those areas that the installers cover with the plastic trims.

I’ve heard someone say this before, and started wondering what’s behind the trims on our windows… what’s the difference between a “properly installed” window and a shonky one in this regard?

As others have said, the frames make a big difference, not much point paying for 3G unless the frames are properly insulated. I bored everyone to death researching the options before spending the cash- not all manufacturers are keen to publish the u-values of the frames, they just concentrate on the glass.

Go ahead and bore me to death with some manufacturers as without reccomendations it’s down to picking from numerous search results from googling ’double glazing’

I would be genuinely amazed if triple glazing from any manufacturer only costs 5% extra!

So why are trickle vents so good then? We have 15 year old UPVC DG windows, all of them left permanently open on the latch at the bottom, permanent condensation and mould issues regardless. (1970s flimsy build)

DG units don’t fail suddenly; it’s an inevitable process that takes a few years to happen. There has to be an in/out flow of air in order to accommodate changes in atmospheric pressure. Pressure increases and air comes in in tiny volumes and brings moisture. The units are built with a moisture absorber which, after some years, becomes saturated and unable to absorb any more moisture. The moisture level builds up inside the unit until it begins to condense.

AFAIK the best way to deal with condensation on an exterior wall is to dry line it. We dry-lined a cold bedroom in an extension and the effect was miraculous.

“AFAIK the best way to deal with condensation on an exterior wall is to dry line it. We dry-lined a cold bedroom in an extension and the effect was miraculous. “

Its also a very good way to hide the condensation where the eye cant see it.

I need to look at our windows. I think they a) have poorly insulated frames, as they feel cold, and b) have been poorly installed. Some of the doors have evidence of damp having come in somewhere but there’s never any wetness inside the house. I suspect that there are gaps somewhere behind the dry lining/cosmetic bits and pieces on the inside.

I stripped off some wall insulation to get at electrics and there was absolutely no sign of damp or condensation, either in or behind it, trail rat.

woodlikesbeer – Member

If you are getting new windows then I would suggest getting trickle vents anyway. Gives you the option of leaving the vents open to get some air through. Especially handy in bathrooms etc. Our old 1970’s bungalow had no trickle vents. We constantly had mould around the house. We couldn’t fit trickle vents to those windows as because of the frame shape.

Fortunately our new house has trickle vents. No mould problems and nice and toasty warm.

I had trickle vents and would recommend against them unless you know they are quality items.
Reasons are firstly that mine didn’t seal perfectly when closed, so there was a constant draft when it was windy, and secondly the trickle vents themselves would regularly need to be taken apart because they got covered with mould. The windows themselves still got condensation and mould growing on them.

Quite possible mine were absolutely rubbish quality as it was in a new build flat. But personally I’d avoid them.

Hey i aint saying it dont work , its a great idea if executed correctly….

Just throwing some drylining at the wall isnt doing it right.

I failed to get trickle vents when I replaced all the windows 2 yrs ago. I had damp/mould problems. I then found I could lock the window when it was very partially open. This combined with a bit more regular heating seems to have solved the problem. I even bought a 10 quid fan heater off Amazon to blast the area vulnerable to mould but it hasn’t been necessary.
Incidentally I dealt with Quantum Windows of Corby and they were amazing for providing well-priced but hi-tech windows and ace customer service e.g. we both screwed up on the measurements for one window, I offered to pay for the replacement, they insisted on paying. I couldn’t recommend them more highly and no, I am not on commission.

We had our windows replaced about this time last year.

I asked about trickle vents and every one who quoted didn’t recommend them. They all said that there’s no point having new double glazing with A+ (or whatever they are) rated frames and windows, then cutting holes in them to stick a vent in.
We went without and we do get condensation on the windows in the rooms that are slept in, but I am not sure whether trickle vents would have solved this problem or not.
It was one of those cases of not knowing what would be best and sticking with the advice of the ‘experts’.

With regards to the triple glazing, we were told that it would add a lot of cost to the windows (can’t remember how much – something like 20% rings a bell, but could be talking rubbish) and wouldn’t be worth the extra expense.
Reading up on it, I’m sure that I read somewhere that the temperature difference (inside to outside) for an average UK winter wasn’t enough to warrant it; it was only in countries that see a much lower temperature for longer periods of winter where it made sense.

That drimaster positive ventilation thing looks interesting – something else to consider for keeping the condensation down!

That drimaster positive ventilation thing looks interesting – something else to consider for keeping the condensation down!

I installed one about 2 months ago off the back of recommendation here and the effect has been significant.

What are the running costs like?

not sure, but its drier and there is less mould in my house so I’m not too bothered.

according to the specs, the main fan doesn’t draw too much and i’ve only got on setting 2/5. I’ve got the heated version that warms the incoming air if its less than 10deg so that will draw a bit more but I live in the balmy SW so it won’t run that often.

jam bo – Member

That drimaster positive ventilation thing looks interesting – something else to consider for keeping the condensation down!

I installed one about 2 months ago off the back of recommendation here and the effect has been significant

My concern would be that it pulls in cold air and creates a draught or just increases the amount of time the heating has run for….how have you found it in that regard?
I take it, it is more of a puff of air coming in rather than a blast?

nemesis – Member

What are the running costs like?

I was looking at Vent Axia ones last night and the website reckoned on something like 2.5 & 13W power consumption depending on fan speed.
The Xpelair one runs at 4-17W depending on fan speed.

My concern would be that it pulls in cold air and creates a draught or just increases the amount of time the heating has run for….how have you found it in that regard?

you can notice a cooler area on the landing below where it is, but then I don’t really spend a great deal of time there.

dry air is easier to heat than wet air.

average humidity levels have dropped from 75-85% to 55-65%

I was looking at Vent Axia ones last night and the website reckoned on something like 2.5 & 13W power consumption depending on fan speed.
The Xpelair one runs at 4-17W depending on fan speed.

those figures are pretty much negligible then though add in the heated versions and I expect they’re much higher.

For damp issues, we bought a good dehumidifier recently, and like the ventilation things, it has massively reduced damp and condensation.
You can see in the morning the lack of condensation on windows, you can feel the better humidity in the house.
The heating has been turned down by a good chunk as the house keeps warmer.
Clothes dry so quickly in the laundry – pop them on drier, dehumidifier in, and an hour later they are dry. Far cheaper than the tumble drier, and saves damp clothes all round the house.

FWIW, the overall performance of frames, glazing and fitting details (cold bridges around the windows) should be your overall concern, not that triple glazing must be better or that one material is better etc. For such an old house, you also need to remember diminishing returns – we have two newer windows in our house and they are the two rooms where condensation is on the (colder than the windows) walls instead of the window unit and glass…

I would be genuinely amazed if triple glazing from any manufacturer only costs 5% extra!

Honest! I bought from John Knight Glass, they quoted £226 extra for a 3G over 2G in a 4 panel (3600mm x 2100mm) bi-fold.

Go ahead and bore me to death with some manufacturers

I liked Schuco and Centor (C1) bi-folds. I went with alu frames. John Knight were very competitive on pricing for both (I have no links to them, just a happy customer).

Hey i aint saying it dont work , its a great idea if executed correctly….

Just throwing some drylining at the wall isnt doing it right.

So what is “doing it right”? You live in an old house with solid walls and condensation running down, so you batten, line with Kingspan and cover with polystyrene-backed board then skim so as to seal the cold wall away from any moisture in the house. Our extension went from being miserable and cold to the warmest room in the house as well as the quietest. What’s to lose?

These postive ventilation units… am I understanding this right? They draw in outside air, heat it a little and force it into the house. Isn’t this the same as the venturi effect over a chimney sucking stale damp air up the flue?

I take it then that trickle vents still aren’t compulsary outside of Scotland?

Globalti – you not gonna put a moisure barrier on there?

squirrelking – Member

I take it then that trickle vents still aren’t compulsary outside of Scotland?

I was told when I had mine done that if trickle vents had already been fitted previously (whether needed or not), then they had to be fitted when the windows are replaced – this is in England.
If they aren’t fitted, then you don’t have to have them. But you can if you want.

globalti – Member

These postive ventilation units… am I understanding this right? They draw in outside air, heat it a little and force it into the house. Isn’t this the same as the venturi effect over a chimney sucking stale damp air up the flue?

Similar, I guess. They draw in air from the loft space, creating a slight +ve pressure in the house, which then forces the stale, damp air out of the house. I don’t think that they all heat the air, although you can get ones that do.