A problem with condensation... help?!

DeVore

Hi there,

Not sure where to turn to with this but just got a new place in Malta. I know the builder and we're both a bit baffled by persistent condensation inside my bedroom's double glazed doors.

Every morning, there is a huge amount of condensation on the inside of two sets of double glazed doors.

Now, Malta is warm during the day and cold at night and the room isn't terrifically ventilated but I have tried leaving a small window open to no avail. Mildew is starting to build now (only 6 months after completion) which is worrying me too.

The whole building is very well insulated but this happens on only some doors and not others (markedly, its the doors that are away from the rising sun but considering this all happens at night... I'm not sure that makes much difference. The temp only gets to about 20 degrees here at this time.

So, any suggestions? Should double glazing not be stopping condensation? The doors surrounds are cold to the touch which I guess is what causes the condensation but I dont know what to do to counter this.

Any help?? Thanks!

DeV.

Poor Uncle Tom

You say the house is finished with 6 months, what are the inside finishes? is it single storey, two storey? what are the floors, timber or concrete?

It may be a case of the structure still has water from a wet finish, and is releasing it. It would condense on the areas of greatest temprature fluctuation, the glazing elements.

It's not good when the mould starts. The answers to the above questions should shed some more light on the situation.

onq

DeVore wrote: »

Hi there,

Not sure where to turn to with this but just got a new place in Malta. I know the builder and we're both a bit baffled by persistent condensation inside my bedroom's double glazed doors.

Every morning, there is a huge amount of condensation on the inside of two sets of double glazed doors.

Now, Malta is warm during the day and cold at night and the room isn't terrifically ventilated but I have tried leaving a small window open to no avail. Mildew is starting to build now (only 6 months after completion) which is worrying me too.

The whole building is very well insulated but this happens on only some doors and not others (markedly, its the doors that are away from the rising sun but considering this all happens at night... I'm not sure that makes much difference. The temp only gets to about 20 degrees here at this time.

So, any suggestions? Should double glazing not be stopping condensation? The doors surrounds are cold to the touch which I guess is what causes the condensation but I dont know what to do to counter this.

Any help?? Thanks!

DeV.

The only issues causing condensation in any building are water coming from somewhere and lack of ventilation.

I can offer a comment, but I have a few questions to ask first.

1. Why, in a climate where the temperature doesn't go below 20 degrees, did you spend money on insulation - was it to prevent heat build-up during the day?
2. How do you know the house is well-insulated - were the window reveals insulated?
3. If you've insulated heavily, did you use a vapour check in the constuction?
4. What is the wall construction - stone, cast concrete, solild/hollow block, twin leaf cavity, timber frame?
5. What is the outside wall covering - if plaster, is it cement or lime based?
6. Are the rooms totally sealed at night - internal and external doors and windows closed?
7. Why don't you just use fly screens - is it to permit the aircon to work?
8. If you're using aircon, is it vented to outside air?
9. Are the rooms pool/jacuzzi areas?
10. Are the rooms bathrooms, bedrooms, kitchens or utility areas?

Sorry for all the questions, but when you're tracing the cause of something from as great a distance as this, you need all relevant information.

ONQ.

DeVore

Poor Uncle Tom wrote: »

You say the house is finished with 6 months, what are the inside finishes? is it single storey, two storey? what are the floors, timber or concrete?

It may be a case of the structure still has water from a wet finish, and is releasing it. It would condense on the areas of greatest temprature fluctuation, the glazing elements.

It's not good when the mould starts. The answers to the above questions should shed some more light on the situation.

Its a two storey and its made from breezeblocks and concrete (tiled) floors.

The condensation is on the metal surrounds on the double glazed door (but only on the one which is facing away from the rising sun, curiously.



Why, in a climate where the temperature doesn't go below 20 degrees, did you spend money on insulation - was it to prevent heat build-up during the day?

The roofing is expanded polystrene and then concreted. Only the roof is insulated in the top floor, but the room up there retains the heat very well and that might be a problem when the door/window surrounds cool down in the night.


How do you know the house is well-insulated - were the window reveals insulated?

The walls are not insulated, only the roof. The window/doors (they are sliding door-windows out onto a balcony), are double glazing but the condensation is forming on the surrounds.


If you've insulated heavily, did you use a vapour check in the constuction?

No, but its not *heavily* insulated. Its 2 inch plastic, expanded polystyrene (dont ask me, I'm just conveying the information I'm getting )


What is the wall construction - stone, cast concrete, solild/hollow block, twin leaf cavity, timber frame?

Hollow block.


What is the outside wall covering - if plaster, is it cement or lime based?

Its plaster but we are not sure which its based on, its a premixture (something-2000) and we think its a mixture of cement and lime.


Are the rooms totally sealed at night - internal and external doors and windows closed?

Yes. There is only a small ventilation hole which worries me.


Why don't you just use fly screens - is it to permit the aircon to work?

Security, these are external doors leading to balcony.[/b]


If you're using aircon, is it vented to outside air?

yes, it is, but we havent even been using Aircon lately.



Are the rooms pool/jacuzzi areas?

No.


Are the rooms bathrooms, bedrooms, kitchens or utility areas?

Bedrooms, but it happens when its occupied or not.

DeV.

onq

Hi DeVore,

I think this is your classic cold surface condensation issue.

Basically warm air suffuses through a set of rooms taking up moisture from living processes in the normal way.

There is no issue arising during the day, but on a clear cloudless night by 4 in the morning the temperature has fallen so far that metal and glass surfaces reach dewpoint, i.e. the metal/glass temperature is below the dew point for the ambient temperature and humidity conditions present.

When it happens you see condensation occurring on the surface of the coldest surfaces - I'm not sure what you mean by surrounds, whether its the frame or the opening in which it sits, but I consider both issues below.

If its the plaster its laid on the coldest part of the construction, the uninsulated block walls that face north, that never quite reach the temperature of the rest of the house.

If its the plaster I suspect the doors are metal framed units that have no thermal breaks.
This allows the frames to lose heat at night and attract condensation in the morning from the air in the minimally vented room space.

HTH

ONQ.

Poor Uncle Tom

As it is early days in the building I think there is a lot of moisture still in the structure from the construction which is releasing and condensing in the coldest areas.

A dehumidifier should help take the moisture from the structure and with good regulated ventilation the mould should stop growing and the condensation should stop.

DeVore

Ok terrific, thanks lads.

I discovered that out air conditioners also have a dehumidifier setting which I have turned on and left running now for a few hours.

The condensation is gathering, not on the windows but on the frames (its a door in fact, made mostly from two panels of double glazing).

The room does feel damp but I'm hoping that that will be cleared by the dehumidifier and as the building dries out (as per Poor Uncle Tom's answer).

I'll let ye know how it goes!

DeV.

muffler

Id agree that a dehumidifier should help (may not necessarily solve the problem completely) but only time will tell. Given the temperatures Id be fairly sure that it is a "drying out" problem. However you could be looking at a couple of weeks before you would see any noticeable improvement but with medium temps. that may be a little earlier.

The moist air may not be the best thing for DeV Snr. but Im not a doc so its something you should possible inquire about.



A little tip: Use a loosely "wrung out" cloth to wipe the mold/mildew away. Mix about an eggcup full of malt vinegar into about a litre of water and throw your cloth into that first and then wring out as described. Should be an improvement after a few days but you need to repeat this daily for about 10 - 14 days. That'll keep you occupied

DeVore

His bedroom is on the sunny side and doesnt suffer from the condensation and doesnt feel "damp". (only one door in my room gets the condensation, the one away from the sunrise, the one on the sunrise side is fine generally). The dehumidifier seems to be doing the job so far though, I'll let you know how it works out...

DeV.

muffler

Yeah, keep us posted please.

onq

DeVore wrote: »

His bedroom is on the sunny side and doesnt suffer from the condensation and doesnt feel "damp". (only one door in my room gets the condensation, the one away from the sunrise, the one on the sunrise side is fine generally). The dehumidifier seems to be doing the job so far though, I'll let you know how it works out...

DeV.

In a country with Malta's climate, the building should be well dried out after 6 months.

Unless there is a source of moisture within the building, like a leaky tank that's drippping into an interstitial cavity [how good are those Malese plumbers? ] this is unlikely to be caused by the building drying out, but you never know.

BTW do you have a gas fire installed anywhere in the house?

ONQ.

DeVore

No, no gas fire.

I dont think its the building's dampness... the air here is usually quite moist so it might be a continuous battle.... I'm hoping not!

DeV.