ᐅ Exterior plaster is uneven, window sills are too short, insulation system is not airtight.

Created on: 30 Dec 2020 23:02
H
Hemingway84
H
Hemingway84
30 Dec 2020 23:02
Preface:

We are building a 190 sqm (2,045 sq ft) city villa to KfW 55 energy efficiency standard with a large general contractor (GC) from Königslutter in the Berlin metropolitan area. The GC uses various subcontractors, who in turn work with their own subcontractors (some of whom also hire further subcontractors). So far, several construction defects have occurred. Serious defects were only prevented through our intervention (for example, the formwork for the intermediate ceiling was several centimeters too low and was literally raised five minutes before the concrete was poured). Unfortunately, the site manager is incompetent, thin-skinned, and unobservant. From day one, he has only offered pointless comments and a lack of motivation. He has never recognized defects on his own and has only reluctantly addressed those we reported, often trying to downplay them with standardized phrases.

As a result, we are on site as often as possible because we are constantly on high alert due to the defects encountered so far. Our involvement has already improved or, from our perspective, salvaged many situations. We have also hired a construction supervisor who has occasionally added value, although his passion seems more for photographing the construction than for identifying defects. Sometimes, a simple tape measure or spirit level helps—at least for us.

Our building project is further complicated by the fact that my wife was diagnosed with cancer a few months after purchasing the land and signing the construction contract. A cruel blow of fate, with chemotherapy and all related side effects, framed by the external circumstances of the ongoing COVID-19 pandemic. The loss of income is unfortunate but was anticipated in the financing—albeit as possible parental leave rather than a long-term illness. Nevertheless, it all makes the situation more stressful than it would have been otherwise.

Main section:

We are approaching the completion of the build; the screed drying will finish next week (the scheduled handover is at the end of January, so we just miss out on the VAT reduction). Ninety percent of the house price has already been paid; only the final invoice, expected in the coming weeks, remains outstanding.

At the end of November, the exterior render was applied. At that time and for the days following, outside temperatures did not exceed 5°C (41°F), with some nights dropping below freezing. According to the render manufacturer (Alsecco), the silicate render used may only be applied at temperatures above 5°C (41°F), and temperatures must remain above this threshold in the following days. If not, the render cannot cure properly, which may lead to issues with strength and durability.

One day before the rendering work began, we sent an informal notice of concern to the GC and their construction manager regarding the weather forecast. The subcontractor responded that there was no need to worry and voluntarily offered an additional one year warranty.

The rendering was completed, but even after one week, the exterior render was still soft. In some areas, it “slid,” particularly on the window sills. Please refer to the attached photos for details.

The same subcontractor who applied the external render installed the window sills shortly before (but only after installing the external thermal insulation composite system (ETICS) and the facade reinforcement). The window sills are crooked and uneven. Some also appear to be too short. On average, they protrude only 2–3 cm (1 inch) from the facade. Some are more uneven, for example with one side 1.5 cm (0.6 inch) and the other side 3 cm (1.2 inches). The drip groove on the underside is often flush with the facade. During installation, alcohol was consumed on site, as evidenced by several dozen small drink containers scattered near the scaffolding. It was also apparently easier to cut our up to 3 m (10 ft) long window sills with an angle grinder to fit them into a car, but sealing the joints afterward was forgotten.

The window sills show no visible sealing. According to trade associations, with an ETICS system, there should be two layers of sealing at the window sills. We can see none. It also seems strange that the window sills were cut into the ETICS. The unnecessarily large gaps created were either left unfilled or only filled with silicone or similar, which after more than four weeks remains soft and uncured.

Water constantly accumulates at the edges of the window sills, running down the facade, further softening the render and freezing in places with the render. Where does this water come from? The screed heating program is still running inside, providing warmth. Could this be a sign of leakage around the windows? Indoor humidity is being actively controlled with three drying units, currently below 40% relative humidity. We suspect leakage because at the most affected window corner inside, we found significant residual moisture along with slight bulging of the interior plaster. Elsewhere, the interior plaster appears superficially dry.

The house base was also poorly finished by the same subcontractor. A very thinly scratched-on reinforcing plaster cannot be the waterproof rendering against moisture as specified in the contract. The layer is simply too thin and, according to photos, remains damp even without rain.

Outlook:

What happens next? The defects have been reported, documented with photos, and recorded. Should we still carry out a conditional acceptance with these defects, or refuse acceptance entirely? We would like to move in by the end of February, as my wife begins her follow-up treatment after chemotherapy in March and does not want the stress of moving to undo all her recovery. The potential double burden is not insignificant.

The render is visibly deteriorated and crumbly, patchy, and simply poorly done. In our opinion, it must be completely removed and redone. The window sills should also be removed and replaced because they are too short and partially cut with an angle grinder without technical necessity. We are particularly worried about the sealing and possible damage to the ETICS. Who knows what will happen in a few years.

Next week, at our own expense, we will engage a publicly appointed expert in painting and decorating to assess the severity of the damage and necessary repairs. From our experience, we expect little or no support from the GC or site manager. We intend to stand firm and will not accept repair work or financial compensation. At this point, we only see one solution: starting over completely. This would be very expensive and could become particularly interesting regarding payment of the final invoice.

The GC has only provided us with a 5% retention guarantee for completion, which likely would not cover a full re-execution of the defective work (and according to the contract text, may only be retained after handover for serious defects). Referring to this guarantee, he has already indicated that he insists on full payment upon acceptance, as we have this guarantee as security and it could be increased or extended.

Any advice, comments, ideas, or suggestions are welcome. I just needed to vent a bit. Sometimes you really feel helpless and lost as a client.

Exterior wall of a modern house facade with a window, earthworks visible


Exterior wall with rough render texture, black stone strip above, moisture marks and dust on the ground.


Exterior wall with rough render texture, vertical render crack below dark window sill.


Close-up of a rough sandstone column on a black granite slab; background with houses.


Close-up of a rough brown wall with white sealing compound in the joint above stone slab.


Exterior view of a gray two-story house with a brown upper section, windows, and door.


White rough wall with a black panel protruding from it and flaking edges.


Exterior wall corner: black granite threshold over white render wall, sealing compound visible.


Wall with moisture damage and flaking render; dusty floor next to a window.


Exterior view of a new build house: dark window sill, white base, loose soil in front.
K
knalltüte
31 Dec 2020 00:33
First of all, my sympathy and best wishes for your wife’s chemotherapy to go well...

With such an illness, you certainly don’t need any issues with your building project.

The problem with the plaster is serious, as is the one with the window sills. Naturally, there must be two waterproof layers, and the installer of the window sills is responsible for the second layer. It’s best if this is the painter who applies the plaster (we faced the same issue and had to discuss it extensively with the trades involved). For this reason, our building has not yet been plastered but will receive a protective film in the next few days as a temporary seal to prevent the external thermal insulation composite system (ETICS) from water damage.

At least the topcoat plaster will have to be removed again (if possible). It will likely cost at least 20,000 until rather 30,000 to 35,000 or more to bring it up to standard according to DIN. You should (must) be firm and not let yourselves be pressured. I would not pay another cent or else you risk overpaying, if that hasn’t already happened.

The expert and the building surveyor must now urgently provide you with professional advice. It is also very important to proceed correctly in a legal and formal sense and not (understandably) react emotionally.

Good luck with your project and best wishes for recovery.

P.S. I have an autoimmune disease and take “cancer medication” in low doses. Because of this, I had to study the topic thoroughly. I can recommend reading “Eating Clean” and similar books. Especially with serious illnesses, nutrition is (inexplicably to me) hardly ever mentioned as a means of faster recovery. I don’t practice it rigorously, but I have partially changed my diet and have noticed improvements.
bauenmk202031 Dec 2020 10:04
The window sill edges should protrude at least 5cm (2 inches) from the facade – at least that’s how I remember it.

Get support to document the facts properly.
Despite everything, I wish you much success and hope you still have a wonderful time in your home!
Wolkensieben31 Dec 2020 14:12
I wish your wife all the best and hope she recovers soon.

I’m very sorry that you’re going through such a difficult time. Sometimes you just have to get everything off your chest, especially in your case.

I hope the issue with the plaster and the window sills turns out well. Wishing you all the best and keeping my fingers crossed for you.
P
parcus
31 Dec 2020 14:38
Hello,
as a general rule, I can only advise you to carefully read what is specified in the plaster approval documents (not just any brochures).
Often, the testing institute refers to air and component temperatures under the test conditions. However, proof of the actual air and component temperatures must still be provided. A nearby measurement point can be helpful in this case.

Regarding window sill installation, there are actually few standards available.
Usually, only recommendations are given because damage is quite rare.

It is not even clear whether a window sill must have a slope, which one would logically assume.
But those who consider this a functional limitation or defect of a window sill may be surprised...
Patricck1 Jan 2021 12:53
What does the site manager say about this topic?

If it starts off like this, the house will certainly require major repairs within a few years. I wouldn’t pay the 10% at all before the house is free of defects.

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