Preventing condensation?

David_Aldred

Hi funkytrousers,
Thank you for the kind words, if you have not read it already please have a look at this thread posting by myself which discusses cavity wall ties and then cavity wall insulation and if you require further discussion please let me know:

http://forums.moneysavingexpert.com/showthread.html?t=2104483&highlight=cavity+wall&page=2

Kindest regards,

David Aldred Indepndent damp and timber surveyor

funkytrousers

Dear Dave,
Thankyou for the reply. I had read most of the post you refer to.
There are two things that resonate with me, Firstly the complete
wall of denial and lack of reponsibility from the installer and EAGA and secondly the SEALING of vents which as you state is 'normal'.
I am completely bewildered by the way that a 'general lack of ventilation'
can be stated as the reason for the problem, but can be treated as a seperate issue to the sealing of vents.
One thing to bear in mind, upon initially seeing the attic, the EAGA guy
did arrange for roof vents to be fitted (against my judgement), however they were fitted without the felt and the layer of insulation (under the felt) being opened. Consequently the attic is colder than before but there is not enough airflow to achieve the objective. I have just had a further though on this, if some warm air is rising and exiting through the vents
the moisture will not be able to permeate the insulation so it presumably will concentrate the moisture and will be more prone to drip in this area.
This could explain the large amount collected in the box which I now
realise was roughly under a vent (you cant see them from inside). I hope you understand that I would prefer the house to function as it did before. If severe condensation and damp are symptoms of an issue I would rather address the issue itself. Although I may appear to be unwilling to accept the findings of the report, as it makes no attempt to find a cause and I feel this would be the most important step.
Could you or would you (or anyone else) please comment on the sealing
of the vents or any other plausible cause, the two 'inspectors' that have seen the property could not find any water penetration or any damp patches on the walls. They both suggested 'lack of ventilation' as the primary cause, despite each attributing it to completely different reasons (definately nothing to do with sealing the vents "per specification". I believe that neither of them were impartial and this is why I am seeking unbiased advice here.
Many thanks

David_Aldred

Hi funkytrousers,
Thanks for the further info - would it be possible for you to take some digital photos of the loft void throughout / the roof vents both externally and where they are located within the loft void internally even though you cannot see them, then some pics of the room vents that were sealed up both from inside the rooms and any corresponding outside photos in the area of the vents. In addition general photos of both the outside and inside of the property. You can send them to me personally if you look on my homepage you can see a contact e-mail address on there or post them on here or join & post to photobucket with relevant link. Any changes that were undertaken that you have not mentioned such as when original fireplaces became disused, when any double glazing was fitted and whether that has trickle vents, what extractor fans do you have andhow do they work / do they overrun, any new rendering and re-pointing in addition to where you are located and how exposed the property is, how many peope are in the proeprty, your lifestyles (are you all out or all in most of the day) etc. The more historic and background information that can be provided the more appropriate the information given will be and photos do tend to say a thousand words. Kindest regards David Aldred Independent damp and timber surveyor

cyclonebri1

Puzzledbubbles wrote: »

the windows are open in the day, closed at night, when i wake up there is the condensation, if i have the windows open at night, even a crack its freezing as we only have the heating on for a few hours each day and not over night or on in the morning.

thanks

I think you just answered your on question there. There only 2 ways to reduce condensation, well 3 if you are prepared to use a dehumidifier all night. I wouldnt take that option as I find them too noisy.

As said you need to either increase ventilation, but that will make it colder, or increase the heating, (hotter air will hold more moisture). The actual answer is do both. The problem is the moisture you breathe out over night not being held by the cold air, nor the air being changed

Leave the window cracked open and get a better quilt, has to be cheapest.

CLAPTON

to ensure your loft is dry you need

1. generous ventilation at soffit board level .i.e. where the roof meets the walls... very often the gaps there are blocked by loft insulation
check the insulation near the outside walls ... you normally should be able to see daylight.

this will allow a little gale to blow through your roof but if you have sufficient loft insulation the main house should not be affected.

2. you need roof / tile vents; as high as possible... this will allow the moist air to escape completely.


it will be cold but should be dry.

cyclonebri1

CLAPTON wrote: »

to ensure your loft is dry you need

1. generous ventilation at soffit board level .i.e. where the roof meets the walls... very often the gaps there are blocked by loft insulation
check the insulation near the outside walls ... you normally should be able to see daylight.

this will allow a little gale to blow through your roof but if you have sufficient loft insulation the main house should not be affected.

2. you need roof / tile vents; as high as possible... this will allow the moist air to escape completely.


it will be cold but should be dry.

Modern synthetic "underfelts" that are breathable do away with the ventillation need to a large extent

Not cold, but dry.

funkytrousers

Hi and thanks a million to those who have posted. It is such a detailed story that I could not fit all the details in the three posts!
We tend to have most of the upstairs windows open unless it is really cold, sometimes even then, there have been no significant changes to our
property for several years before the Boiler/CWI installation.
You cant leave downstairs windows open overnight but the kitchen window would normally be opened when boiling/steaming and for an hour after. The condensation affects every window upstairs and down.
I would appreciate your views how to deal with the installation company and the governmental agencies as they have so far all tried desperately to point the finger away from themselves without actually providing a suuitable explanation logically which fits the circumstances.
Yes I understand about roof vents, tricke vents, extractor fans, dehumidifiers and the like but none of our neighbours need them and we didn't for the 12 years we lived here prior to the installation.
I have desperately tried to just get an answer I can trust because we could cure the symptoms tomorrow by the obvious steps and comments mentioned.
The simple fact remains that the house was never cold before, the heating was not used for 8 months of the year and the fire hardly used at all. It did not lose the heat at night. Its impossible to measure as the weather is not a constant, but subjectively the house is not warmer. The central heating should be broadly similar but probably a bit quicker to warm as the radiators are newer and double-skinned. As it is controlled by a thermostat, the heating goes off when the desired temp is reached so the house is not necessarily WARMER, it probably gets to temp quicker.
Hope this detail helps clarify, I will be collating some photos etc for DAVE ALDRED over the weekend but generally would like to hear your ideas and how others found the cause not necessarily how to lessen the effects of condensation or how they managed to get the installers etc to do the right thing, I do not trust them, the CWI installer has so far been inept after the event.
HELP HELP HELP!!