Key Post: Attic Condensation

Re: Attic Condensation

I don't think you'll find anything in the regs, express or implied which says the builder ought to have fitted a duplex board- it certainly would be good practice and preferable. however do try and negotiate on price/ remedial action but in this economy if you walk away he'll probably get another buyer after Christmas anyway. I work for a large developer and if a buyer proves sticky or unreasonable (and I'm certainly not implying you're either!) this is what developers will do (seek return of contracts). It's a sellers market so unless you can demonstrate clear breach of contract, non compliance with building regulations or serious defect you're position is weak unfortunately.
 
Re: Attic Condensation


Hi Carpenter,
I think I might be in the clear...
[broken link removed]
I found a better description on the above page... The drywall sealer would provide vapour control and quote "is Suitable for decoration with paints and most wall coverings"...

I recon he could apply this to the inner side (bedroom walls), sort the extractor fan in bathroom to vent to the outside and sort out the 50mm ventilation gap in the roof space (that is a definite requirment) and we should be in business...
The bedroom walls have been skimmed would this matter... Is this sealer just for the boards themselves or can it go on the skim?

Another question/point...
My surveyor seemed to think that the insulation to the first floor beedroom ceilings should be rigid insulation (I assume a polystyrene type) and that fibreglass wasn't building reg compliant. But I can't find this anywhere in the actual regulation (2002 TGD) is he talking rubbish here..?
Nobody I've spoken to since has ever heard of this.
 
Re: Attic Condensation


Ultimately, the buyer has to sign - nobodys walking away in the current market. However, what you can do is prolong the process to put the pressure back on the builder. A 'major structural defect' can hold up closing. Do a comprehensive snag list including the stuff thats not necessarily all that important to you - prioritise snags and bargain accordingly.
I was threatened with loss of deposit/house and on a number of occassions told to take my money back and sling my hook if I wasnt satisfied. Whilst things are tight financially for new home owners, builders have their own financial pressures. Cashflow is a fundamental part of any business and if theyre not getting the money in, then they may be more inclined to fulfill their responsibilities and do the snags/honour the original contract so that they can get the 'paid in full'.
 
Re: Attic Condensation


Well I sorted it out today... The builder looked at the extractor & agreed it had to be sorted.
We talked about the 50mm gap & again he'll do that as it's reall easy & just a matter of making sure the insulation is all the way down into place & that can be sorted.

I spoke to a technical guy at Gypsum industries about the duplex board & as far as he was concerned as long as the roof void was vented there shouldn't be any major problem.
The builder wouldn't do the plasterboard, but we made a deal for me to take €2,000 as a cashback & hold it for 9 months subject to the house passing the building regulations (as that was the only remaining worry I had)...
Basically I want the house & he want's to sell so we checked what was needed & comprimised.
Thanks to everyone for all there advice & expert opinions...
 
Re: Attic Condensation

I think you've reached a fair compromise there, best of luck in your new house.
 
Re: Attic Condensation

Could someone please explain the 50mm gap - is this between the top of the insulation and the roof felt?
 
Re: Attic Condensation

Geegee said:
Could someone please explain the 50mm gap - is this between the top of the insulation and the roof felt?
Click to expand...

Yes that's exactly right but only applies to 'Room in roof' attic conversions or Dormer bungalows...
If yours is a straightforward 2 storey with open attic you should have felt above your head & insulation below your feet in the attic...
Sorry to refer you to this again but it shows it diagramatically:
http://www.environ.ie/DOEI/DOEIPol.nsf/0/a137e0322d60e09780256f5d00504a79/$FILE/30178%20BR%20Ventilation%20F.pdf
Look at diagram 6 on page 11... Conventional is type A & you'll see that the 50mm gap rule is only for roof void/attic types shown in D... (i.e. attic conversions & dormers)
 
Re: Attic Condensation

Mine is a standard two storey - what could be causing the condensation then?
 
Re: Attic Condensation

I had this problem after getting a new and more powerful range,the guy came and fitted a bigger expansion tank (not sure what that is) in the attic and the problem went away..
 
Re: Attic Condensation

With proper venting, moisture should vent to the outside and not collect in the attic.

Ventilation slits should be at least equal to continuous ventilation running the full length of the eaves - 10 mm wide...

Ideally half of the venting should be at the eaves or overhang of the roof, and the other half should be at the gables or near the ridge of the roof.

Condensation should be further reduced if the insulation on the attic floor has a vapor barrier that resists moisture migration, this would be on the warm side of the insulation..


Evaporated water migrates through the home and if it can get no other way out (i.e. vents, windows & extractors) it ends up condensing in the easiest cold place it can migrate to in the winter - The attic.

Assuming your attic is vented properly, the next step is to find and reduce excess sources of this migrating moisture inside the home. Major contributors to high moisture levels are baths, showers, laundry, water leaks and blocked flues or room vents.

You mentioned that you had turned off your bathroom fan at the isolator... This is fine as long as you open the bathroom window for showers & baths (the steam has to go somewhere) but the extractor is better...
Avoid drying clothes on the radiators in winter, use a drier & make sure it is vented or use a condenser drier...
Finally make sure your room vents are open & flues are not blocked... The room vents in Irish homes can seem like a big hole fore the heat to go out but fresh air has to be able to circulate through your rooms somehow...

Have the boiler and fireplace flues checked annually for possible blockage or back-drafting problems. Also make sure the plumbing vent pipes & overflows vent through the roof to the exterior & there are no leaks here.
Vent hoses in the attic are best under the insulation and vented properly past the overhang.

Hope this helps & if it doesn't I don't know anything further you can do...
 
Re: Attic Condensation

"My surveyor seemed to think that the insulation to the first floor beedroom ceilings should be rigid insulation (I assume a polystyrene type) and that fibreglass wasn't building reg compliant. But I can't find this anywhere in the actual regulation (2002 TGD) is he talking rubbish here..?"

While there probably isn't a prohibition as such in the building regs, fibreglass insulation in the sloping part of a dormer roof is not a great job. With the passage of time, it will compact down, leaving an uninsulated area near the top of the slope. Also, it is more difficult to maintain ventilation (the insulation will not keep its shape, but will tend to fill the space, so you need to insert something - pipes or spacers - to maintain an airflow between the insulation and the felt).

One other point: best not to install spotlights in the sloped part of a dormer roof. The heat may not dissipate properly (and even if you make a proper gap, insulation may shift), and if you are unlucky enough to have the spotlight near a roof timber, the concentrated heat could create a fire hazard.
 
Re: Attic Condensation

Update on the original problem: since my original post got in contact with the builder who again blamed the felt. The providers of the felt Richmond BP building suppliers, they sent out a rep as they did last year. They then wrote a report on how the felt fitting instruction where not adhered to (as well as the building Regs). Basically high level vents are required and the attic door being a bit of a DIY job. This report and a vague threat got some results: The builder came yesterday and fitted high level vents so will have to wait for the next cold spell to see if these are successful.

The curious think about the situation is I called into my next door neighbour (non adjoining house) and that house did not have the problem at all. That house has less vents than ours, has no insulation at the back of the attic door, and the shower extractor fan is not connected to anything!!!
 
Re: Attic Condensation


Perhaps this house has a more southerly exposure (warmer roof space), is more exposed to prevailing wind or the house has less occupants/ or the occupants open windows regularly/ don't do much cooking in the house. it's a strange one all the same.
 
Re: Attic Condensation

To Serotoninsid: Holes in the wall should be avoided where possible but a damp attic is to be avoided as well. Keep the moisture out from the attic, by putting a barrier between the source, for example the in situ shower cabin , and the ceiling/attic. And the of course you have to ventilate any airborne moisture out of the building, except you are using a dehumidifier. So ventilation needs a hole , preferable combined with a ventilator and a heatrecovering system. A simple way to safe that money is to open the window in the bath room/shower for a few minutes. That method is called "rapid ventilation" and is cheap and straight forward. However if the building situation doesn't allow for it ( no window, openings to small) then you should consider a heat recovery ventilation system. Even a cheap and plain propellor in the ceiling should doe the trick provided it doesn't blow the air straight into the next room or the attic where it would condense on cold surfaces. The ferry boats between Ireland and the rest of the world (smiley) with their shower cubicles use exactly the same system. Many hotels do so as well. When you can't use the "rapid ventilation" then use a heat recovery unit. It doesn't have to be a heatpump , that would be very pricy, a simple ventilator that preheats the infiltrating air with the aid of energy contained in the exhausted warm air.
And any outlet from a ventilator to the environment should of course be covered with flaps that would close when the machine is not in use.
If you have a larger project to be supported with a ventilation system it might be worth to combine the outlets of several shower cabins/kitchen hoods and smokers corners , but that is a job for a heating/ventilation engineer.There the heatpump might be worth to be considered.
 
Re: Attic Condensation

Thanks Heinbloed. I am going to sort something out with them for sure. But first, its time to get the house signed over - its 3 months overdue as a result of my efforts to force them to sort out other problems.

I havnt mentioned this problem to them yet but will do once I get keys and the opportunity to sort out flooring/tiling etc. I wouldnt normally like to leave any snagging till after closing but it would be a clearcut case legally were they to refuse to sort it out ie. a clear breach of building regs.
 
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