# Condensation in Attic Dripping down from the Felt onto the Insulation



## chippy (20 Jan 2011)

Hi All,please can anyone advise me?
I was up in the attic today and i noticed that water droplets{condensation] are covering the entire surface of the felt lining on one side of the roof felt lining.the front side of the roof is dry,there is so much moisture it is dripping onto the insulation which is now quite damp in places.The rafters are also beginning to look very damp with water content.
There are vents in the soffits  but there are none in the roof tiles or cable.
The house is a semi-detached and is only 5 years old.
Please can anyone tell me will this effect the roof in time leading to major damage from rot and dampness getting through to the the ceilings etc etc.   
Who would be liable for to correct this situation,the builder of the house,the surveyor who signed it off as correctly built or Homebond which the builder has a 10 year gaurantee with.
All your advise would be most appreciated.
JC


----------



## fraggle (20 Jan 2011)

It could also be a central heating problem. I have heard of overpumping, where the pump is too strong, and there might be a blockage in the heating pipes... the hot water gets backed up into the tank in the attic causing steam.


----------



## chippy (20 Jan 2011)

Hi thankyou fraggle for that piece of advise i will check it out.
I have tenants in this house,so i will be out there again to do a few jobs.
I will  enquire off the other neighbours if they have had a similiar problem.


----------



## chook (20 Jan 2011)

There should be (inside>outside)
rafters > (breathable) membrane > vertical laths (for ventilation) > horizontal laths > rooftiles

It sounds like in your case the moisture from the inside of the house can't escape and thus condensates at the coldest point which is between insulation and felt.
Common construction mistake.


----------



## chippy (20 Jan 2011)

Hi chook thanks for your thoughts,have you any solutions ?
Should there have to be air vents installed in the roof tiles or maybe the gable end of the house?
Will Homebond cover this work that the builder neglected to do as i will be wasting my time chasing the builder.
If left undo could there be major roof problems in the future?
JC


----------



## fraggle (20 Jan 2011)

Homebond won't cover something like this. Ignore homebond unless the majority of houses in the estate have major faults.

You can't leave the rafters getting wet. I would start by getting an insulation/roofing person in.


----------



## chook (20 Jan 2011)

JC, there should be a continuous path for airflow between ridge and eaves to take moist air away. You need the condensation point to be away from the rafters and insulation, i.e. on the outside of the membrane where the moisture can escape through the vertical path between the bottom set of laths.  If you look at the image here:
(I'm not yet allowed to post links, hence the www dot ...)
www dot palktareloghouses.com/index.php?id=15317&lang=en&tpl=1067
you can see the construction I mean. Kingspan also has images and considerations at www dot insulateonline.com/index1.htm?pitchedintro.htm~main
I'm no expert. It's just how I was taught it should be done. I agree with fraggle. Get in an expert.


----------



## roker (20 Jan 2011)

I had this problem last year, apart from the soffit vents being covered with insulation; the extract duct from the shower was not taken the outside, only lying inside the soffit


----------



## chippy (20 Jan 2011)

Hi Roker you have hit the nail on the head,i did a further investigation up in the attic today.
The 3 extract ducts have only been taken to the soffit and have not been fitted properly out through the soffit,the timber work around these areas is soaking from moisture.
More Celtic tiger workmanship!!!!!
While i am rectifying this matter i have been advised opening the hatch door will help with drying out the moisture.
Thankyou Roker
Chippy


----------



## mosstown (20 Jan 2011)

who would be responsible for the ducting of the shower extractors, the electrican ? or another trade ?


----------



## timoney (20 Jan 2011)

Should not be difficult to extend these fans to vents. Also make sure that all the vents on the rest of the soffits are clear from insulation as condensation is a common problem in attics where they are not properly vented.


----------



## chippy (20 Jan 2011)

Hi Mosstown, it is a plumbers job to duct the vent,but im sure some celtic tiger plumbers will disagree.
Hi Timoney, have you read all of my post? Fans have been vented to a pipe,problem is the pipes have not been connected to the outside world,hence all the condensation  in the attic.
Chippy


----------



## chippy (20 Jan 2011)

I can fix this problem myself,but has anyone any idea who can i ask  to  question this builder on his past activities because he is only laughing  at my little problems!!!
When a builder puts in the electrics for an immersion heater in the hot  water boiler but does not insert an immersion in the boiler and declares  when questioned it is not his responsibility,then who is responsible?.
When my own personal plumber tells me the plumbing system  in this house  should not have been signed off on by the builders engineer because it  is not upto scratch,what goverment agency will sort out this builder????
This builder is now presently looking for planning permission up the  road for serviced sites, in this day and age, and he has not finished  off his last project properly.
Has anyone coped on yet in these planning offices? 
Chippy


----------



## chippy (20 Jan 2011)

Hi Chook,not trying to be funny but are you reading  from some construction manual because you sound like you have never been up in an attic in your life.
Please correct me if i am wrong.
Chippy


----------



## chook (20 Jan 2011)

Chippy you are wrong. I have worked with people on roof renovations on a couple houses in Germany and I now live in a house that needs a new roof so I have lately been refreshing the theory part. And I sleep in an attic every night, literally looking at rafters and roof tiles ...  
ps. none taken


----------



## chippy (21 Jan 2011)

No problem chook,
I appreciate your input
Kind Regards
Chippy


----------



## villa 1 (21 Jan 2011)

chippy said:


> Hi Mosstown, it is a plumbers job to duct the vent,but im sure some celtic tiger plumbers will disagree.
> Hi Timoney, have you read all of my post? Fans have been vented to a pipe,problem is the pipes have not been connected to the outside world,hence all the condensation in the attic.
> Chippy


 That's not true. It is not in the plumbing apprenticeship training programme for plumbers to connect and install ducting, whether it is rigid or flexible from extract fans 
You are wrong, so don't be blaming the "Celtic tiger plumbers"
The remit of fitting these hoses/ducts normally falls to the builder of the property.


----------



## chippy (21 Jan 2011)

Hi Villa thankyou for your imput  I expected this answer,so who does the builder employ to fit the {Ducting} then ,please can you tell me. 
I have some guttering that needs replacing aswell, i suppose that is not a plumbers job either!!!!


----------



## villa 1 (21 Jan 2011)

chippy said:


> Hi Villa thankyou for your imput I expected this answer,so who does the builder employ to fit the {Ducting} then ,please can you tell me.
> I have some guttering that needs replacing aswell, i suppose that is not a plumbers job either!!!!


 In most cases it's a general operative(very handy guys) working with the building company who fit the extract pipes/hoses
Guttering and sheet metal roofing zinc, copper, lead etc used to be under the plumbers remit(in this country) but has since gone, big shame. 
You need to contact a guttering company if you have guttering problems.


----------



## roker (21 Jan 2011)

It would appear that there are regulation for all of the construction, but no one checks it when complete, even the engineer who we paid when we purchased the house missed a lot of these points. So what is the point of regulation? The House Guarantee scheme will only look at major defects. The builder wins.

Regarding the vents, in my case there was already a vent tile fitted, so it took a builder 30 mins to connect it.


----------



## BillK (21 Jan 2011)

The plumber who refitted our bathroom ducted from the fan over the new shower cubicle to the soffit and vented it.


----------



## bstop (22 Jan 2011)

This problem could be caused by foggy ( water saturated ) air from outside entering the attic . The weather conditions over the last few nights could cause this internal condensation to form. Outside air ventilation will not always have a drying effect. If the outside temperature rises quickly it will be warmer than the temperature of the roof felt. if this air is near 100% relative humidity it will condense when it hits the roof felt.

The same effect happens in unheated garages. Objects like cans of paint will reach low temperatures during prolonged cold spells. If the outside temperature rises and the relative humidity of this outside air is very high condensation will form on the cold objects in the garage. When this happens it will often be possible to see the level of paint in the can by observing the height of the condensation on the outside of the can.


----------



## bstop (22 Jan 2011)

I checked my attic this morning. It is normally bone dry. At present there is slight dampness in some of the rafters at the upper edge where they contact the roof felt, and in isolated patches there is slight dampness on the felt itself. This is only on the north facing side of the roof as it is slightly colder than the south facing side. I reckon that the more ventilation the attic has, the more this effect will occur in certain weather conditions.


----------



## roker (22 Jan 2011)

bstop, I have worked on humidity measuring equipment, I need to clarify your statement. 
If you heat up cold air it becomes dryer, and is able to absorb more moisture. (the measurement is called (RH or relative humidity) the air must obtain the moisture from somewhere, if not it should dry your attic if it is heated up. The air in the house takes up moisture because of the fact we are living in it, breathing, cooking, washing, etc. If air leakes from the house in to the attic it bring with it moisture and condenses in the cold parts and possibly cause dripping. The attic should be sealed from the house to prevent air entering, convected heat from the house should heat the attic without moisture.
All holes including the attic hatch should be sealed.


----------



## bstop (22 Jan 2011)

i am talking about warmer air (say 5 degrees C) entering from outdoors into a colder attic ( say 0 degrees C) and being cooled in the attic and causing the described condensation. This can occur due to a rapid increase in outdoor temperature and often this warmer air is moisture laden Atlantic air due to a warm front. A well ventilated attic will behave in a similar fashion to the outdoor environment and will suffer condensation on cold surfaces.
Did you ever notice an outdoor oil tank in these weather conditions. Condensation will form on the tank up to the level of the oil in the tank. This is because the oil remains cold long after the outside air has warmed. Similarly the attic surfaces will be slower to heat up than the outside air and will attract condensation.


----------



## jeananne (22 Jan 2011)

I had the same problem with condensation on attic felt during the very  cold weather last year - only realised there was a problem when we saw  small damp patches on the plasterboard in the attic conversion... got  into a big panic about it afraid the rafters would be damaged or the  insulation would get wet etc. Discovered when I was up there that the  shower extractor fan was vented directly into the attic space ...  Couldn't wait until summer to get tile vents fitted and proper venting  of shower - never did either in the end because the condensation  disappeared as soon as the cold spell ended. 
I do wonder if it would be worth getting that foam insulation sprayed in  between the rafters. They're advertising it at the moment, claiming to  prevent pipes ever bursting - would it prevent the condensation ??? Or  does the felt need to "breath" ?


----------



## konline (30 Jan 2013)

Hi Jeananne and all, 
  Sorry I am reopening this thread after 2 years .
I have the same problem in my attic. I have recently fitted a ladder in to my attic and put 100 sq ft of attic flooring. 4 weeks ago when I saw the amount of condensation on the felt I was shocked. I have called in a plumber immediately and fixed all three vents which were left opened (celtic tiger builder work) in the attic and also put a dehumidifier for 3 days which extracted nearly 8 litres of water.
  It looked dry for the next one week but condensation came back again on the felt. It looks bad.

  Did you ever fix this condensation problem in your attic? If Yes, can you please share your solution?

Thank you very much.




jeananne said:


> I had the same problem with condensation on attic felt during the very  cold weather last year - only realised there was a problem when we saw  small damp patches on the plasterboard in the attic conversion... got  into a big panic about it afraid the rafters would be damaged or the  insulation would get wet etc. Discovered when I was up there that the  shower extractor fan was vented directly into the attic space ...  Couldn't wait until summer to get tile vents fitted and proper venting  of shower - never did either in the end because the condensation  disappeared as soon as the cold spell ended.
> I do wonder if it would be worth getting that foam insulation sprayed in  between the rafters. They're advertising it at the moment, claiming to  prevent pipes ever bursting - would it prevent the condensation ??? Or  does the felt need to "breath" ?


----------



## lowCO2design (30 Jan 2013)

is there adequate air circulating in the attic space? have you inadvertently blocked the ventilation at the eaves with insulation?


----------



## konline (31 Jan 2013)

lowCO2design said:


> is there adequate air circulating in the attic space? have you inadvertently blocked the ventilation at the eaves with insulation?



Hi, thanks for your reply.
I think there is adequate air circulating in the attic because I feel it very cold when I go up. 
I have no idea if the ventilation at the eaves is blocked. I put 100 sq ft of attic flooring in the centre of the attic, that's all. 
How do I check if I have blocked ventilation at the eaves?

Thanks again.


----------



## roker (31 Jan 2013)

You should see day light where the vents are fitted


----------



## Leo (31 Jan 2013)

If you're up there today, with the strong winds, you should feel the flow of air through the attic.


----------



## lowCO2design (1 Feb 2013)

konline said:


> Hi, thanks for your reply.
> I think there is adequate air circulating in the attic because I feel it very cold when I go up.
> I have no idea if the ventilation at the eaves is blocked. I put 100 sq ft of attic flooring in the centre of the attic, that's all.
> How do I check if I have blocked ventilation at the eaves?


that's your problem so
http://www.environ.ie/en/Publicatio...ng/BuildingStandards/FileDownLoad,1647,en.pdf
start reading on p 26


----------



## konline (1 Feb 2013)

Thank you Roker,Leo and lowCO2design for your replies. 

I couldn't feel the wind in the attic, when I came home last night there were no winds.

I see a little bit of light from the edges of the roof. So I think some ventilation is provided in the attic but I don't feel wind coming in to the attic.

Thanks for the document, it gives lot of information. I should look at "effective seal to the attic access hatch"... because we fixed this a few months ago. From outside it looks fine...


----------

