Moisture Issue in Loft New Build

[Grzyb]

Hi All,

Just a quickie...

Daughter moved into a New Build April of this year...It's only a 2-Bed End Terrace type Property, but very cosy..

Since she has No Garage & very little storage, I recommended her to have Part of the Loft Boarded for some "extra" Storage, we have it on a 30-Year Old New Build & have never had any issues....

So with the Bad Storms we have had lately, she mentioned that some Damp is coming through in the Bedroom & some Growth behind the Bedside Tables, When we checked the Loft, It was very Damp & Full of Moisture...

Crux of the Matter is we Contacted Persimmon, the House Builder & they are coming out to investigate on the 14th, we told them of the boards & they have already said that if the boards are the issue, then they will wash their hands of any liability, only Part of the Loft has been boarded & the boarding is on Stilts so nothing is really "enclosed"....

What are people's thought's?? If Persimmon blame the boards, as I'm 100% sure they will, I can remove them myself & see if it "cures" the Problem, if it is still there & clearly an issue, what next?? Do I try & get someone to fit some extraction/ventilation Fans in the Loft to aid in Air Circulation?? Would an Independent Inspection be worthwhile & if so, how do I go about getting one organised...

I've attached some Photos & There is a link to a small Video File below....

https://www.dropbox.com/s/0mx7cqqhjuaxxqj/ec3cafc2-aa2d-4cb8-ac3f-8b440aae85ec.mp4?dl=0

Thanks in Advance for any replies......

 

[JohnD]

the insulation appears to be pushed into the eaves. Can you pull or roll it back enough to see daylight? This will greatly improve loft ventilation.


Do any of the ceilings have holes in them, for example for downlights?

Does the loft hatch fit well?

you mention "Damp is coming through in the Bedroom & some Growth behind the Bedside Tables" so this appears to be a general humidity and condensation problem, not a Loft problem. Nothing in the loft (except a roof leak) would cause damp in the bedroom.

Is wet washing ever draped inside the home? This is a common and terrible source of humidity, damp, condensation and mould in UK homes.

Does the bathroom have an effective extractor fan, and is it used?

When are the windows opened?

Would an Independent Inspection be worthwhile & if so, how do I go about getting one organised...

If, as I suspect, the excess humidity is caused by occupant behaviour, you can pay a consultant to tell you what I will tell you for nothing.

Open the windows, and put up a washing line in the garden.

 

[freddiemercurystwin]

the insulation appears to be pushed into the eaves. Can you pull or roll it back enough to see daylight? This will greatly improve loft ventilation.

If the membrane is breathable there shouldn't be any moisture, furthermore because the the membrane is breathable there won't be a route for ventilation at the eaves anyway as the membrane is supposed to do that job.

What are the neighbours roofs like? This is important and should be investigated and can help build your case.

 

[BlueLoo]

So, be quite specific as to where the damp is and isn't, understanding that moisture can be from a number of causes.
The builder will do all he can to blame the flooring. You need to be sure and be eloquent in your responses to prove that it isn't.

Damp in the bedroom might not be caused by the loft. its usually caused by lack of ventilation in the room itself. Make sure the room vents are clear and that any trickle vents in the windows are open.

Moisture in the loft is usually caused by lack of ventilation. as the poster above says, the eaves are full of insulation. This isn't something to argue over. tell the builder to rearrange the insulation properly.

Damp from the flooring in the loft can be caused by over packing of the void under the floor surface. i believe there should be 50mm gap below the board to allow for movement of air.

The above is uninformed opinion but i am trying to get you to see that sometimes, the causes are not obvious.

Best of luck.

 

[^woody^]

There is a known issue with breathable membrane not working as the manufactures made out, and it is well documented that condensation on the underside like you have there is common, and not necessarily a defect or problem with the construction or the membrane. It's mostly one of perception as the membrane still lets moisture evaporate, but the nature of how it is made allows moisture to coalesce on the surface, giving the impression that it is not breathable.

To deal with this, manufacturers have developed membranes with greater breathability and different construction, but the use of these is not widespread.

That's not to say that there are not issues with other parts of the roof or construction, and you will need expert advice on this. One of the leading new home snagging consultants is Snagging Expert Hertfordshire - Snagging Consultant, and they can advise.

It's very difficult to pinpoint any one reason or apportion blame on the builder for instances like this, as the cause can be a combination of several things. So unless there is something blindingly obvious, you may have a difficult time in proving a defect under the Buildmark Scheme.

 

[Grzyb]

the insulation appears to be pushed into the eaves. Can you pull or roll it back enough to see daylight? This will greatly improve loft ventilation.

OK Will try moving the Insulation a Bit away from the Eaves....


Do any of the ceilings have holes in them, for example for downlights?

She has no Down lights whatsoever

Does the loft hatch fit well?

The Original one fitted fine, Can't comment on the one fitted by the Loft Boarding Company, as a Loft Ladder was fitted at the same time...But I will check, Do u recommend putting some tape around the seals for a Test??

you mention "Damp is coming through in the Bedroom & some Growth behind the Bedside Tables" so this appears to be a general humidity and condensation problem, not a Loft problem. Nothing in the loft (except a roof leak) would cause damp in the bedroom.

That is why Persimmon the Builders are coming to Investigate on the 14th, to see if it is a Roof problem...

Is wet washing ever draped inside the home? This is a common and terrible source of humidity, damp, condensation and mould in UK homes.

Maybe now, that the Winter Month's are with us, In the Summer, I fitted her an outside Washing Line.....But it Rains everyday!!! So I suspect that there are clothes on Radiators etc...I have Ordered her a Dehumidifier from Amazon, so hopefully that will help a bit....

Does the bathroom have an effective extractor fan, and is it used?

Yes, Whatever Persimmon Installed & when I was there last it was on 24/7....

When are the windows opened?

That I do not know, I suspect Windows are closed as she is very Cold!!! & likes the Warmth....

If, as I suspect, the excess humidity is caused by occupant behaviour, you can pay a consultant to tell you what I will tell you for nothing.

Open the windows, and put up a washing line in the garden.

 

[Grzyb]

If the membrane is breathable there shouldn't be any moisture, furthermore because the the membrane is breathable there won't be a route for ventilation at the eaves anyway as the membrane is supposed to do that job.

Good Point, I will ask on the 14th, whether they have used a breathable membrane.....

What are the neighbours roofs like? This is important and should be investigated and can help build your case.

That was the first question that I asked her to find out?? As if it is affecting her neighbours as the walls are all adjoining, then regardless of the boarding there is an issue.....

 

[JP_]

If the membrane is breathable there shouldn't be any moisture,

I had same problem with new loft. I think some "breathable" membranes are better than others ... and some are just rubbish.

You need air vents somewhere. If you don't sort it you loft will start rotting, attracting woodworm etc.

 

[Grzyb]

So, be quite specific as to where the damp is and isn't, understanding that moisture can be from a number of causes.
The builder will do all he can to blame the flooring. You need to be sure and be eloquent in your responses to prove that it isn't.

Understood, that is why I am trying to find out what to say & do, as I'm not a Builder, just a lousy DIYer....

Damp in the bedroom might not be caused by the loft. its usually caused by lack of ventilation in the room itself. Make sure the room vents are clear and that any trickle vents in the windows are open.

Hopefully the Dehumidifier will do it's Job....Maybe when the Weather Improves, it will get better....

Moisture in the loft is usually caused by lack of ventilation. as the poster above says, the eaves are full of insulation. This isn't something to argue over. tell the builder to rearrange the insulation properly.

So Would Fitting an external FAN through the Outside Wall help with Ventilation, her's is the End One in the Row of 2-Beds??

Damp from the flooring in the loft can be caused by over packing of the void under the floor surface. i believe there should be 50mm gap below the board to allow for movement of air.

The above is uninformed opinion but i am trying to get you to see that sometimes, the causes are not obvious.

Yes, A bit of a minefield, which I am only just beginning to understand....

Best of luck.

 

[Grzyb]

I had same problem with new loft. I think some "breathable" membranes are better than others ... and some are just rubbish.

How Did You Sort Yours Out in the End?? If you don't mind me asking??

You need air vents somewhere. If you don't sort it you loft will start rotting, attracting woodworm etc.

That is why I want to be on the Top of it & Not Wait until Persimmon pull their fingers out with Options......

 

[Grzyb]

There is a known issue with breathable membrane not working as the manufactures made out, and it is well documented that condensation on the underside like you have there is common, and not necessarily a defect or problem with the construction or the membrane. It's mostly one of perception as the membrane still lets moisture evaporate, but the nature of how it is made allows moisture to coalesce on the surface, giving the impression that it is not breathable.

To deal with this, manufacturers have developed membranes with greater breathability and different construction, but the use of these is not widespread.

That's not to say that there are not issues with other parts of the roof or construction, and you will need expert advice on this. One of the leading new home snagging consultants is Snagging Expert Hertfordshire - Snagging Consultant, and they can advise.

Thanks for the Tip, I will bear them in mind, once We hear a definitive response from Persimmon....

It's very difficult to pinpoint any one reason or apportion blame on the builder for instances like this, as the cause can be a combination of several things. So unless there is something blindingly obvious, you may have a difficult time in proving a defect under the Buildmark Scheme.

Yep, I'm not really looking to apportion blame & since I recommended the Loft Boarding to my Daughter, I feel responsible for the consequences...So just want it sorting...

 

[BlueLoo]

I watched your vid

I had same problem with new loft. I think some "breathable" membranes are better than others ... and some are just rubbish.

You need air vents somewhere. If you don't sort it you loft will start rotting, attracting woodworm etc.

This loft seems to have no ventilation at all, either in thee eaves, or roof vents.
Is this the latest way to design these roofs, with a breathable (goretex esque) membrane acting as a large surface area ventilation through the tiles?

 

[Harry Bloomfield]

So with the Bad Storms we have had lately, she mentioned that some Damp is coming through in the Bedroom & some Growth behind the Bedside Tables,

Those comments on their own, suggest to me excess moisture being generated inside the house, plus lack of adequate ventilation. Basically - drying clothes in the house, boiling pots without lids, baths and showers without turning extract fans on, or ventilating afterwards. The moisture in the house, will also find it's way into the loft and condense on the coldest part - the roof.

A humidity gauge might be helpful, to confirm it.

 

[^woody^]

"Responsibility" is probably a better work than "blame".

But yes from the builder's perspective, removal of insulation to add boarding, ie reducing the performance of the ceiling insulation and thus allowing more warm air into the loft to then condense, could be deemed a contributory or single factor.

But that's not to say that there are not other issues - eg have foil backed plaster boards been used where they should have been or should the roof void be able to deal with this regardless, so you need expert advice on this.

 

[Grzyb]

I watched your vid


This loft seems to have no ventilation at all, either in thee eaves, or roof vents.
Is this the latest way to design these roofs, with a breathable (goretex esque) membrane acting as a large surface area ventilation through the tiles?

Your Guess is as Good as mine??