Window problem

Atlantic1

The double glazed window unit in my son's room is not very wide. Assuming that the 2 panes are 4mm each, I reckon that the space between them is only about 6mm. Maybe 8mm max! Every morning it's heavily covered with condensation.

I've put insulated plasterboard on the revilles recently so changing the whole window would be a lot of hassle.

Would a replacement glass (only) unit with argon gas and K glass make much of a difference or will I have top bite the bullet and go for a whole new window?

MicktheMan

Any issue with condensation in the other rooms?
Is the glazing in your sons room different to other rooms?

Atlantic1

MicktheMan wrote: »

Any issue with condensation in the other rooms?
Is the glazing in your sons room different to other rooms?

Hi Mick. No condensation issue in the other 2 bedrooms, both of which are south facing. However, those bedrooms have 28mm units as opposed to the one I referred to in the original post which is north facing.

I could change the entire window but I recently internally insulated the bedrooms and also around the revilles so that would be a bit messy.....

MicktheMan

So the problem is in a north facing room. This may indicate that the window is not the real issue, just a symptom. And more importantly, if condensation is forming on the cold glazing, what's then happening at the back of your insulated dry lining?

Was there a condensation problem before you insulated?

How well is the house ventilated? Are clothes being dried indoors (on a clothes horse for instance). Is the house being heated adequately?

Atlantic1

Yes, there was always a condensation problem on the window in the room but never on the walls. The guy who did the insulating thought it was a single glazed window! The glass unit really is very narrow. I reckon no more than 16mm max.

No clothes being dried in the house. The room is heated but the rad is sometimes turned off if the room isn't being used.

MicktheMan

While there wasn't condensation on the walls before the insulating, doesn't mean there isn't now. Search for the term "interstitial condensation" for more info.
Again, how is the house ventilated?

Atlantic1

I know what institial condensation is. I found out after I realised that I should have insulated with foil backed insulated plasterboard. I used TW52 and should have used TW56 or something similar.

I reckon the only ventilation is through open windows.

I posted this last night. Is it a good idea?

MicktheMan

Atlantic1 wrote: »

I reckon the only ventilation is through open windows.

So no ventilation then. If I were you I would tackle this first. Perhaps inform yourself how ventilation works (I mean the physics of what's happening) and the inter-relationship between heating, ventilation, moisture load, condensation etc. Then, when fully informed, choose the best ventilation system for you situation.

Atlantic1 wrote: »

I know what institial condensation is. I found out after I realised that I should have insulated with foil backed insulated plasterboard. I used TW52 and should have used TW56 or something similar.

I posted this last night. Is it a good idea?

A good idea might be to get professional advice before you make any more costly mistakes:)

Atlantic1

Thanks again, Mick. You're right about the professional advice. I might PM you about that some time in the future as you're not a million miles away from me.

My original plan was to go for external insulation. About 6 m2 of the front of my house is stone faced so I got a local insulation company out to give me a price for the whole hose, less the stone faced part. (I was going to go the insulated plasterboard route on the inside of that wall rather than applying for planning permission to change it. We're in a park of identical houses). It's a 3 bed semi. He quoted me €9000 to do it.

I spoke to a builder and he said that he could replace the stone front on the house at a reasonable cost and about 9 months later, I asked the same company to come back to give me a price for the whole house.

In the meantime, the insulation grant scheme had been introduced and his new price was €13800! The grant was €4000 at the time...............

MicktheMan

You need to be careful when getting ewi done that shortcuts are not taken such as not going up past the soffit and down to the footings. As you also have a cavity block wall (hollow block), how will probable convection currents in the hollow columns be dealt with. If not addressed, your ewi may well underperform and/or the risk of mould increase.
When retrofitting fabric related energy upgrades, different aspects and effects need to be considered to achieve the desired effect and avoid other related problems. In my experience, few contractors (especially those that have sprung up since the grants were introduced) are knowledgeable of these and, as I said earlier, get independent professional input sooner rather than later.