# Wind getting in at lean-to roof



## chippengael (16 Sep 2011)

Hi,

I have a 2 storey 3 bed semi where the kitchen extends a meter or two out into the garden. The lean -to roof of this extension meets the external wall of the house half way up, and is sealed with lead flashing. The prevailing wind hits this side of the house and wind is howling into the blocks and through the walls at this intersection. The house is 17 years old.

What can be done? 

Is it necessary to lift the tiles of the lean-to roof, and pump foam into the region where the roof meets the wall to seal it up? Or is it simply a case of replacing the flashing? 

Any ideas appreciated. 

C


----------



## hastalavista (16 Sep 2011)

To me what the issue is here is that your house has internal drylining on the walls that were dabbed on with no full seal top and bottom of the sheets of plasterboard.
The wall vents in the wall were piped only to the inside face of the block, leaving a gap between the inner block face and the plaster board.
The wind gets in here and all around the house.

I dont think its the lead flashing, but I have been wrong...


----------



## onq (16 Sep 2011)

Your description doesn't give enough detail to make a determination.
Even a full photograph inspection probably won't show enough.

You need to get a proper inspection done on site.
Be prepared to pay for limited opening up.

Wind doesn't blow through walls.
I doubt its the flashing.


ONQ

[broken link removed]

All advice on AAM is remote from the situation and cannot be relied upon                            as a defence or support - in and of itself -       should       legal        action    be      taken.
Competent legal and building professionals should be asked to advise in                            Real Life with rights to inspect and issue     reports    on     the         matters    at      hand.


----------



## chippengael (19 Sep 2011)

Hi

Am I looking for a roofer to make this assessment, or a builder?

Thanks


----------



## hastalavista (19 Sep 2011)

take off one of the inner grills on your wall vents and see what sort of construction you have before you call anyone


----------



## onq (19 Sep 2011)

@ chippengael

Inspecting yourself without taking professional advice is of limited use.
You should appoint an architect or building surveyor to inspect and offer independent advice.
Asking the person who will carry out the work to advise means the advice received is not 'independent'.
The value of independent advice is that it is offered without fear or favour, and is one reason why an architect cannot also be a contractor.


ONQ

[broken link removed]

All advice on AAM is remote from the situation and cannot be relied upon                             as a defence or support - in and of itself -        should       legal        action    be      taken.
Competent legal and building professionals should be asked to advise in                             Real Life with rights to inspect and issue      reports    on     the         matters    at      hand.


----------



## chippengael (19 Sep 2011)

hastalavista said:


> take off one of the inner grills on your wall vents and see what sort of construction you have before you call anyone


 
Looks like 9 inch cavity blocks. 

C


----------



## hastalavista (19 Sep 2011)

chippengael said:


> Looks like 9 inch cavity blocks.
> 
> C



Block Plastered on the outside and plastered/skimmed on the inside?

No dry-lining on inside?

How can you tell they are 9" cavity?


----------



## chippengael (19 Sep 2011)

hastalavista said:


> Block Plastered on the outside and plastered/skimmed on the inside?
> 
> 
> No dry-lining on inside?
> ...


 
Actually, externally insulated since 1 year on the outside, but ineffective due to wind entering the structure somehow, suspect the kitchen roof line as vents etc sealed externally as much as possible. 

Walls have platerboard on inside, but suspect no insulation behind.

Looking into the ESB box, or down a vent lets you know we are dealing with cavity blocks. 

Right now I think it might be best to remove the tiles, insulate as much as possible the roofline and seal it up....

C


----------



## onq (19 Sep 2011)

If the wall is 225mm/9" cavity its possible that someone who tried to hack out a channel for the flashing has in fact breached the skin of the blockwork, which is ~ 25mm/1" thick.
This is rank speculation on my part, but it would explain why the wind seems to be coming through at that location.
If wind is getting in, so could rain, so look out for damp spots below the flashing.

The wind penetration may have nothing to do with the flashing at all.
The top course may not be sealed with 100mm on the flat.
This effectively leaves the structure totally open.


ONQ

[broken link removed]

All advice on AAM is remote from the situation and cannot be relied upon                              as a defence or support - in and of itself -         should       legal        action    be      taken.
Competent legal and building professionals should be asked to advise in                              Real Life with rights to inspect and issue       reports    on     the         matters    at      hand.


----------



## hastalavista (19 Sep 2011)

chippengael said:


> Actually, externally insulated since 1 year on the outside, but ineffective due to wind entering the structure somehow, suspect the kitchen roof line as vents etc sealed externally as much as possible.
> 
> Walls have platerboard on inside, but suspect no insulation behind.
> 
> ...


Did the external insulation cover all the wall vents externally?

If not and given what you say about the internal plaster board, I will repeat what I first wrote:



> To me what the issue is here is that your house has internal drylining on the walls that were dabbed on with no full seal top and bottom of the sheets of plasterboard.
> The wall vents in the wall were piped only to the inside face of the block, leaving a gap between the inner block face and the plaster board.
> The wind gets in here and all around the house.



In addition where does the wind actual come out in the house?

Did the external insulation stop above the flashing?


----------



## chippengael (20 Sep 2011)

hastalavista said:


> Did the external insulation cover all the wall vents externally?
> 
> If not and given what you say about the internal plaster board, I will repeat what I first wrote:
> 
> ...


 

We insulated over the vents externally in most of the rooms. Only the kitchen and living rooms were not covered over as they have a gas boiler & fire in them. 

The air seems to circulate through the walls and appears in unusual places - coming up through the floorboards in the bedroom, even from the toilet flush. We found a gentle breeze blowing out of an electrical socket! 

The insulation stopped above the flashing. When the wind hits the roof it is directed up into this join and I suspect this causes the problem. 

Of course you have to bear in mind that it is a semi-detached house, and my neighbour did not have his house externally insulated at the same time. 

There is one more issue that we have not been able to recitfy - the external insulation was built around the bathroom downpipes leaving them encased. A bad smell built up in there which was finding its way back into the house so we had to place vent holes in the insulating box, thus more or less destroying the insulating capability of this part of the insulation. 

The company which did the job has been paid and is ignoring us strenuously. 

C


----------



## onq (20 Sep 2011)

You appear to have blocked all the permavents to most of the habitable rooms.
Have you installed a mechanical ventilation and heat reclamation system to supply air?

Bad air from a pipe should not have built up in the way you describe if there is a vent pipe.
Who did this company get to check that the work they did complied with the building regulations?

I'm beginning to think this is going to be a horror story of how not to an existing semi-d insulate externally.
The touble is that there is only so much advice you can give remotely, as well as after the fact with work covered up.


ONQ

[broken link removed]

All advice on AAM is remote from the situation and cannot be relied upon                               as a defence or support - in and of itself  -         should       legal        action    be      taken.
Competent legal and building professionals should be asked to advise in                               Real Life with rights to inspect and issue        reports    on     the         matters    at      hand.


----------



## hastalavista (20 Sep 2011)

I think onq has just about nailed it: serious issues emerging here.


----------



## onq (20 Sep 2011)

Well, all I've done is queried it hastlavista, based on what the OP has posted and the obvious implications of same.
I'm concerned that there may be people who don't understand the implications of covering over permavents without providing -
(i) an alternative means of supply fresh air when the windows are closed 

and 

(ii) an adequate supply of air to gas appliances.​The consequent reduction in air quality can lead to complications, from -


 general drowsiness, to


 respiratory problems to


 possible fatality
    - especially where the lack of fresh air is combined with a build up of fumes from say a badly burning gas appliance.

I would strongly suggest that the local Bórd Gáis inspector out to ensure that both the gas appliances - boiler and fire have got sufficient supply air to them.
I would also suggest that an architect be retained to inspect the completed dwelling for compliance with the Building Regulations.

ONQ

[broken link removed]

All advice on AAM is remote from the situation and cannot be relied upon                                as a defence or support - in and of  itself  -         should       legal        action    be      taken.
Competent legal and building professionals should be asked to advise in                                Real Life with rights to inspect and issue         reports    on     the         matters    at      hand.


----------



## hastalavista (21 Sep 2011)

Just to add here:


> even from the toilet flush


 by the OP is a scary item and because of this I would be getting the sewage issue sorted first as the draughty house may be a life saver if there is ANY ingress of sewage fumes into a house where, by all accounts the basic ventilation requirements are not being met


----------



## chippengael (21 Sep 2011)

hastalavista said:


> Just to add here:
> by the OP is a scary item and because of this I would be getting the sewage issue sorted first as the draughty house may be a life saver if there is ANY ingress of sewage fumes into a house where, by all accounts the basic ventilation requirements are not being met


 
OK, where to begin. 

1. We have left open vents in rooms which have boilers/fires, as I believe I have stated already. We're not completely stupid! The vents could be reopend easily in other rooms such as bedrooms etc, but for now we use our windows when necessary. MHRV would be a good idea if we had actually managed to insulate our house effectively - which we haven't.

2. I would agree that the company which carried out the external insulation job are rubbish. However, they were SEI listed and the finished work was inspected by SEI and the grant was approved and paid. Furthermore, they were recommended highly by friends of ours, which was unfortunate. They certainly botched a few things which I am trying to remidiate. The fact that air is circulating unhindered through part the structure underlines one of the issues. There are others, but lets not get too far off topic. 

Having lived abroad for years it puzzles me as to why we think it is necessary in Ireland to have holes knocked in every room in our house...?

C


----------



## onq (21 Sep 2011)

chippengael said:


> OK, where to begin.
> 
> 1. We have left open vents in rooms which have boilers/fires, as I believe I have stated already. We're not completely stupid! The vents could be reopend easily in other rooms such as bedrooms etc, but for now we use our windows when necessary. MHRV would be a good idea if we had actually managed to insulate our house effectively - which we haven't.
> 
> ...



1. The house as you describe it appears contravene the Building Regulations Part F and may be potentially life threatening. The issue is whether it is getting background adequate ventilation to maintain air quality. Common methods include- an MVHR system
- permavents in walling or glazing
- some sort of on-demand vent-in-wall system​Its your choice, but I'd get the place looked at immediately.

2. The previous government brought forward new regulations and "approved details" which do not appear to take circumstances  like yours into account. Companies with limited understanding of building physics appear to be making decisions and carrying out work to satisfy these new regulations which may put laypeople at risk from the effects of inadequate ventilation.

3. The original topic has been fully addressed - further speculation will fail to bring more clarity. You were the one who introduced new issues to which regular posters to AAM have responded in good faith. The fact that air is circulating through the structure may be the house's saving grace, in the context of the lack of ventilation elsewhere as hastalavista suggest.

4. It is unlikely that addressing one isolated symptom on an online forum will adequately deal with all the problems affecting your dwelling. You should consider appointing an architect or building surveyor who understands building physics and is competent to interpret the building regulations to attend, inspect and issue a report with recommendations.


ONQ

[broken link removed]

All advice on AAM is remote from the situation and cannot be relied upon                                 as a defence or support - in and of   itself  -         should       legal        action    be      taken.
Competent legal and building professionals should be asked to advise in                                 Real Life with rights to inspect and  issue         reports    on     the         matters    at      hand.


----------



## onq (21 Sep 2011)

@ chippengael,

Just for the record.
I didn't state, suggest or imply that you were stupid.

I didn't suggest that the company who carried out the work was rubbish.
The  company carrying out the work are responsible for carrying it out  compliantly.

I think this kind of situation may test the limits of  liability for insulation installers where no architect is appointed. 
Do they have a responsibility to  ensure that alternative ventilation is being provided where if block  existing permavents in the course of their work?


ONQ

[broken link removed]

All advice on AAM is remote from the situation and cannot be relied upon                                  as a defence or support - in and of    itself  -         should       legal        action    be      taken.
Competent legal and building professionals should be asked to advise in                                  Real Life with rights to inspect and   issue         reports    on     the         matters    at      hand.


----------



## chippengael (21 Sep 2011)

onq said:


> @ chippengael,
> 
> Just for the record.
> I didn't state, suggest or imply that you were stupid.
> ...


 
Hi again,

I do appreciate the comments, thanks. 

I don't have high regard for building regs as they allowed the use of 9 inch cavity blocks to build the swiss cheese wind tunnell which we paid so dearly for. I just don't buy the need for vents in every room. 

I think a legal challenge would be an interesting avenue, but more expensive that the original job. 

The original question has not been answered though. I guess I should call some of my architect friends, they would be happy to get some work I suppose. 

Thanks again, 

C


----------



## hastalavista (22 Sep 2011)

chippengael said:


> The original question has not been answered though.
> 
> C



The question has been answered.
The consensus, based on what you have written, is that its not the flashing and the contributors were trying to eliminate other possibilities.

I have asked you twice for a specific answer to how the internal pb is fixed to the wall and if the wall vents in the block work are ducted out to, and sealed into, the face of the pb or is there  a gap between the inner face of the pb and the block work. A visual inspection will require the inner grille to be taken off and if the hole in the pb is not big enough to shove your hand in then enlarge it to feel/see the gap if any.

This construction problem is widespread in 100's of houses all across the country, I have carried out remedial work on close to 100 at this point so I am aware, first-hand,  of the issue.

You are quite entitled to rant on about your views on building regs and the like as well as exhibit a cynical and disparaging attitude to the current dearth of work for architects 





> I guess I should call some of my architect friends, they would be happy to get some work I suppose.



However it would be helpful if you could answer the question.

The above quote begs the question: why did you not engage with them earlier?


----------



## onq (22 Sep 2011)

chippengael said:


> I don't have high regard for building regs as they allowed the use of 9 inch cavity blocks to build the swiss cheese wind tunnell which we paid so dearly for.


Any form of construction must be sealed to prevent unwanted penetration by the wind.


> I just don't buy the need for vents in every room.


The requirements for ventilation under Irish Law is given in TGD F Ventilation and depending on when your building was built.
There are two guides available online although an earlier 1997 document exists -

TDG F 2002

TGD F 2009

These may help you assess the way the building should have been built originally.
If the upgrading of insulation has occurred recently, then these may inform you how to achieve compliance.

You could familiarize yourself with the law before approaching your architect in order to better prepare for the meeting.
There are alternatives as noted above - providing adequate air changes is a common sense requirement for healthy living - Posts #15 and #18 refer.

I advise against ignoring the law and rendering your building non-compliant with the building regulations.
This could have serious implications for the health of your family and your house insurance might not cover you in the event something occurs.



> The original question has not been answered though.


Please read the thread posts again.
It was specifically answered in Post #6 above in terms of who should inspect.
The issue of whether and how this related to the flashing was specifically covered in Post # 10 above, which describes how the chase for the flashing might have cut into the block.



> I guess I should call some of my architect friends, they would be happy to get some work I suppose.


This is what Post # 6 advised, because of(i) the limitations of an online forum when dealing with an defect that requires an on site inspection
and
(ii) the possible limitations of laypersons when assessing technical matters involving building physics
​Advice is only as good as the competence of the person offering it and the willingness of the person asking for it to take it one board.
Having offered what advice I can in this forum and included the relevant building regulations to guide you, I'll leave it at that.


ONQ

[broken link removed]

All advice on AAM is remote from the situation and cannot be relied upon                              as a defence or support - in and of itself -         should       legal        action    be      taken.
Competent legal and building professionals should be asked to advise in                              Real Life with rights to inspect and issue       reports    on     the         matters    at      hand.


----------



## chippengael (22 Sep 2011)

hastalavista said:


> The question has been answered.
> The consensus, based on what you have written, is that its not the flashing and the contributors were trying to eliminate other possibilities.


 
Yes, and in that context we got into the sealed vents issue, which I don't think is the source of the problem, but which became the focus of subsequent discussion. Maybe I missed it, and if so I'm sorry, but how did we conclude the flashing at the roofline is not at fault?



hastalavista said:


> I have asked you twice for a specific answer to how the internal pb is fixed to the wall and if the wall vents in the block work are ducted out to, and sealed into, the face of the pb or is there a gap between the inner face of the pb and the block work. A visual inspection will require the inner grille to be taken off and if the hole in the pb is not big enough to shove your hand in then enlarge it to feel/see the gap if any.


 
The vents are simply holes knocked into the cavity blocks - no ducting. 



hastalavista said:


> This construction problem is widespread in 100's of houses all across the country, I have carried out remedial work on close to 100 at this point so I am aware, first-hand, of the issue.


 
Fair enough, you know your stuff. 



hastalavista said:


> You are quite entitled to rant on about your views on building regs and the like as well as exhibit a cynical and disparaging attitude to the current dearth of work for architects


 
No, I actually do have good friends who are unemployed architects, and I am sorry for them. I wasn't being being cynical and disparaging as you suggest so lets not engage in name calling.



hastalavista said:


> However it would be helpful if you could answer the question.
> 
> 
> The above quote begs the question: why did you not engage with them earlier?


 
In my case, the insulation company hired a qualified architect to talk me through the project. She convinced me of the merit of doing the work, and carried out the BER examination at the end. She did not share your sense of alarm regarding the vents. Ultimately we did not see the insulation improvement we expected, and I have been trying to troubleshoot ever since.


----------



## onq (22 Sep 2011)

chippengael said:


> In my case, the insulation company hired a qualified architect to talk me through the project. She convinced me of the merit of doing the work, and carried out the BER examination at the end. She did not share your sense of alarm regarding the vents. Ultimately we did not see the insulation improvement we expected, and I have been trying to troubleshoot ever since.



This is the first time you mentioned the involvement of an architect.
This is a very important issue for you as the party complaining of non-compliant work.
Given the issues raised above by hastalavista and the undersigned, you should address your concerns to the insulation company and her.

Was a BER Certificate and Report issued to you after the work was carried out?
The benefit of insulation may be seriously compromised where there is an airflow within the structure allowing convection currents to reduce internal temperatures BEHIND the insulation.
In terms of knowledge of how building physics works this is a fairly basic issue and should have been taken on board when reviewing the likely performance of the upgraded property for a BER report.

Let me make it clear by way of an extreme example of a cold winters night.
Picture a house with 200mm of insulation separated from the house wall by a 100mm cavity.
In your case the cavity in question approximates the ventilated voids within the 215mm hollow blockwork

That 200mm of insulation is not going to achieve its potential if the structure surrounding the house is full of holes.
The temperature of the wall reduces towards the ambient external temperature because of the convection currents in the cavity.
Its like someone going outside on a winter's day who wears a coat but doesn't button it up allowing cold air to circulate inside near the body.

The house won't be quite so bad as if no insulation existed because the building will not "see" the night sky it might otherwise "see" without the insulation in place.
Radiant heat loss is reduced, but the convection currents in the cavity will lower the temperature of the wall they pass by significantly because they are at the temperature of the outside cold air.

Happy to stand corrected by any physicists reading this.
You should ensure any architect you ask to comment is competent in this area, otherwise you might be wasting your time.


ONQ

[broken link removed]

All advice on AAM is remote from the situation and cannot be relied upon                               as a defence or support - in and of itself  -         should       legal        action    be      taken.
Competent legal and building professionals should be asked to advise in                               Real Life with rights to inspect and issue        reports    on     the         matters    at      hand.


----------



## chippengael (26 Sep 2011)

Hi again, 

To be fair, the architect did issue pre-project recommendations for vents: 

*Fan & Vents​*This dwelling has one or more fans/vents.
Fans and vents increase heat loss in a dwelling by allowing heated air to escape but
can be important in ensuring adequate ventilation. If there is no cover on the inside of
the vents, installing controllable vent covers will allow you to control the air flow
through the vents, and so can help reduce heat loss. All changes to ventilation must
comply with relevant Building Regulations requirements, particularly Part F
(Ventilation) and Part J (Heat Producing Appliances).​*Cost: *Low *Impact: *Low
 
We made the decision to clover vents ourselves in rooms with no fires. Controllable vent covers on the inside of the rooms will do little if cool air is flowing around the structure compromising the efficacy of the external insulation. 

The ingress of air into the structure was not as obvious post insulation, and we became aware of it over time. 

As we were starting with such a leaky structure, my decision was to try eliminate as much as we could, and then add ventilation as required, eg. trickly vents on windows as we replace them, or even reopening the vents which is easily done. 

I guess we will continue to try eliminate leaks as we go, and review the ventilation as required. I am still concerned that the roofline needs workthough. 

Thanks

C


----------

