ᐅ Incorrect Installation of Interior Roof Insulation Caused Significant Damage
Created on: 5 Jan 2024 15:23
W
Winniefred
Hello!
I need to tap into the collective knowledge here.
In 2017, we bought a house built in 1921. The roof is from 1993 and has a vapor-tight (!) underlay membrane, which was common at the time. In 2017, we converted the attic and had it insulated by a drywall contractor. For that, they added battens, pressed the insulation wool tightly against the underlay membrane, then added insulation beneath the rafters, followed by a vapor retarder foil, and then the drywall.
So far, so good. However, during Christmas 2023, we had a storm/rain damage because the connection between the chimney and the roof became leaking. The roofer lifted some tiles there and found water everywhere. On the entire roof, there is condensation between the insulation and the underlay membrane. He checked under the tiles from outside on all sides of the roof. Afterwards, we opened part of it from the inside—everything was wet (well beyond the chimney area—the insulation around the chimney was drenched from the rainwater leak, while the rest of the roof only has condensation between insulation and underlay membrane).
The roofer told us the interior insulation was done incorrectly. They should never have pressed the insulation directly against the airtight underlay membrane but created some ventilation space of a few centimeters. Now all the damp insulation wool must be removed, which is a huge effort and a major cost. The chimney leak was sealed, and it will require proper repairs in spring, but that is clearly separate from the condensation damage. The condensation problem probably would have gone unnoticed until the drywall started to rot.
What do you think? Does anyone have experience with this and any tips, ideas, or suggestions? Is it possible to hold the drywall contractor accountable? There is already light black mold on the beams, and the entire insulation plus drywall must be removed, disposed of, and replaced. I estimate the cost to be roughly 10,000–15,000 EUR. Only the thinner insulation mats beneath the rafters are dry and might be reusable. We don’t expect any goodwill from the drywall contractor. We want to take legal action if possible; after all, we hired a professional company back then to prevent exactly this kind of issue. We paid a significant amount, and it was only six years ago.
I need to tap into the collective knowledge here.
In 2017, we bought a house built in 1921. The roof is from 1993 and has a vapor-tight (!) underlay membrane, which was common at the time. In 2017, we converted the attic and had it insulated by a drywall contractor. For that, they added battens, pressed the insulation wool tightly against the underlay membrane, then added insulation beneath the rafters, followed by a vapor retarder foil, and then the drywall.
So far, so good. However, during Christmas 2023, we had a storm/rain damage because the connection between the chimney and the roof became leaking. The roofer lifted some tiles there and found water everywhere. On the entire roof, there is condensation between the insulation and the underlay membrane. He checked under the tiles from outside on all sides of the roof. Afterwards, we opened part of it from the inside—everything was wet (well beyond the chimney area—the insulation around the chimney was drenched from the rainwater leak, while the rest of the roof only has condensation between insulation and underlay membrane).
The roofer told us the interior insulation was done incorrectly. They should never have pressed the insulation directly against the airtight underlay membrane but created some ventilation space of a few centimeters. Now all the damp insulation wool must be removed, which is a huge effort and a major cost. The chimney leak was sealed, and it will require proper repairs in spring, but that is clearly separate from the condensation damage. The condensation problem probably would have gone unnoticed until the drywall started to rot.
What do you think? Does anyone have experience with this and any tips, ideas, or suggestions? Is it possible to hold the drywall contractor accountable? There is already light black mold on the beams, and the entire insulation plus drywall must be removed, disposed of, and replaced. I estimate the cost to be roughly 10,000–15,000 EUR. Only the thinner insulation mats beneath the rafters are dry and might be reusable. We don’t expect any goodwill from the drywall contractor. We want to take legal action if possible; after all, we hired a professional company back then to prevent exactly this kind of issue. We paid a significant amount, and it was only six years ago.
Winniefred7 Jan 2024 15:09It is not my responsibility as a layperson to check the work of the professional. At that time, I was 28 years old and had two children aged 1 and 3 years. I was on the construction site every day, working and studying. So no, there was no time to supervise the professional. Sorry, I can only smile about that right now.
Winniefred schrieb:
It is not my responsibility as a layperson to check the work of the professional. At that time, I was 28 years old and had two children aged 1 and 3 years, was on the construction site every day myself. I was working and studying. So no, there was no time to supervise the professional. Sorry, I can only smile about that right now. That was by no means meant as a criticism. I myself am still quite naive about many things (even though I was twice your age at the start of construction). That is exactly why I wrote: "Why don’t ‘laypeople’ hire a paid expert to supervise the project, someone who represents the owner?" and I am always surprised how few actually do it, even though it is usually the biggest expense of their lives.
Also, and especially as a suggestion for others in similar situations, my post was intended. I wish you good luck and success with the renovation—perhaps this time accompanied by an expert report?
Winniefred7 Jan 2024 18:57I don’t think it should be necessary to hire an expert for roof insulation if you hire a local contractor who comes recommended. I also don’t know anyone who has hired an expert for something like that. We did most of the work ourselves back then, but we didn’t dare to handle the insulation because it is so prone to mistakes. In hindsight, we probably could have done it better ourselves because I would have studied the details thoroughly and likely noticed any issues.
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Allthewayup7 Jan 2024 19:18Winniefred schrieb:
It is not my responsibility as a layperson to check the work of the professional. On a personal level, I completely agree with that. Unfortunately, what I had to learn very quickly during the house construction is that if you don’t do this, you will definitely be at a disadvantage. I could write a book about what went wrong, was done incorrectly, or unprofessionally. And when I think that apart from me, no one else complained or would have complained, I’m glad to have been one of the “demanding” homeowners. By now, I research every major work package to understand what is happening, how it is done, and how I, as the client and owner, can still influence the quality.
Winniefred schrieb:
The issue with the roof and the insulation has actually been going on for quite some time. The first suspicion arose in 2019, and we had drywall installers and roofers inspect it. In the end, they agreed that the damage was limited because only two staple holes were not sealed. We let it dry out and then closed it up again. Despite repeated calls, the roofer never showed up for the promised roof inspection, so we assumed it was fine and dry and left it at that. At that time, it had only been about 2 years since the work – does that make any difference?A construction lawyer could give you a much more precise answer – but I think it will still be very difficult. 2019 would not be a problem by itself, but unfortunately, you didn’t file a defect notice at that time. Maybe the incident could help prove intent to deceive if you could argue that the drywall installers should have realized by then that they had done faulty work.
What exactly was offered and billed by the drywall installer?
Winniefred schrieb:
The problem is: if you rely on professionals, you get let down. But how are we supposed to know about these things as laypeople? There’s simply no chance to notice something like this—until it’s too late.I’m sorry for your situation, but that’s really how it is: supervising or approving any work without a building expert is foolhardy as a layperson. By 2019 at the latest, you should have brought someone in, because neither the drywall installers nor the roofers were impartial.
Winniefred8 Jan 2024 08:56Harakiri schrieb:
A specialized lawyer can, of course, give you a much more specific answer – but I believe it will still be very difficult. In 2019 it wouldn’t have been a problem, but unfortunately you didn’t file a defect notification at that time. Maybe this incident might help prove fraudulent intent if one could argue that by then the drywall contractor should have realized that they had done the work incorrectly.
What exactly was offered/billed by the drywall contractor?
I’m sorry for your situation, but the truth is: overseeing or accepting any work without a building expert is suicidal as a layperson. By 2019 at the latest, you should have involved someone, because neither the drywall contractor nor the roofer are/were impartial. I’m copying the relevant part of the invoice here, without names and figures. Nothing more is stated in the invoice.
"Dismantling of existing drywall paneling including substructure and mineral wool.
Removal and disposal of construction debris including landfill fees.
66.60 m² (717 sq ft) addition of timber battens 40 x 60 mm (1.6 x 2.4 inches), dried, to the beam structure.
66.60 m² (717 sq ft) installation of thermal insulation between the rafters in the sloped roof area.
Insulation material: between-rafter insulation, Integra clamp fleece, WLG 032, 180 mm (7 inches) thick.
66.60 m² (717 sq ft) Intello, a humidity-variable vapor retarder.
Install vapor retarder and wind-tight layer on the underside of the rafters according to standards, sealed wind-tight.
46.93 m² (505 sq ft) underspar clamp fleece supplied and installed in the substructure.
WLG 032, 30 mm (1.2 inches)
46.93 m² (505 sq ft) sloped ceiling drywall paneling, gypsum board, wooden substructure,
1 layer 12.5 mm (0.5 inch) GKB gypsum board.
Install DIN 18 181 standard wooden substructure mounted to the beam structure with suitable fasteners.
Board gypsum panels onto wooden substructure.
Filling and taping done by the client.
Gypsum board (GKB) 12.5 mm (0.5 inch)
3 units covering reveals around the Velux windows.
16.00 linear meters (52.5 feet) drywall facing frame, substructure supplied and mounted as knee wall.
4.78 linear meters (15.7 feet) drywall facing paneling with gypsum boards.
1 sack (25 kg / 55 lbs) joint compound including 1 roll of joint tape."
But I still maintain – requesting an expert for every single job is neither necessary nor usual. It would be too much to pay not only the high craftsman costs but also expert fees to supervise the master contractor. By the way, the invoice specifies "Master contractor for acoustics and drywall."
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