ᐅ Exposed Roof Structure – Where Should the Vapor Retarder Be Installed?
Created on: 23 Jun 2018 11:52
S
Snowy36
It’s me again…..
A brief recap: we are building a KFW 55 house through individual contracts with a construction supervisor.
We have exclusively chosen local suppliers, some of which have been in business for three generations. I mention this because it’s reasonable to expect they know what they’re doing and have solid experience.
We have an exposed timber roof frame insulated with wood fiber insulation boards from Gutex. The roof is installed but not yet covered with the final roofing material.
Yesterday, the building inspector came and asked us about the roof structure. We explained it to him, and he suggested we check with the Central Association of German Carpenters to determine the required performance class (I assume it’s class 3 since the standard roof pitch would have been 28 degrees, and ours is 19 degrees), and of course, the roof is part of the living space.
We looked into how a roof like this should be constructed and read that a vapor retarder and a nail sealing tape must be used.
Here is our build-up:
On top of our spruce multilayer panels, we installed an Alujet Professional JKE underlay membrane, then the 20 mm (0.8 inch) wood fiber boards, followed by a hardwood multiplex plywood board, and then, overlapped, another layer of Alujet Professional JKE, and finally the counter battens.
We are annoyed that we didn’t receive any nail sealing tape, but maybe this is acceptable due to the use of the Multiplex plywood. What I’m more concerned about is: where exactly is the vapor retarder? The Alujet Professional JKE doesn’t seem to have that function.
We have now sent an email asking the carpenter for clarification, but I’m afraid, as often happens, we’ll just be reassured without real answers…..
Unfortunately, the roof construction is specified exactly like this in the contract…..but as a layperson, you wouldn’t know that it might be wrong…..
A brief recap: we are building a KFW 55 house through individual contracts with a construction supervisor.
We have exclusively chosen local suppliers, some of which have been in business for three generations. I mention this because it’s reasonable to expect they know what they’re doing and have solid experience.
We have an exposed timber roof frame insulated with wood fiber insulation boards from Gutex. The roof is installed but not yet covered with the final roofing material.
Yesterday, the building inspector came and asked us about the roof structure. We explained it to him, and he suggested we check with the Central Association of German Carpenters to determine the required performance class (I assume it’s class 3 since the standard roof pitch would have been 28 degrees, and ours is 19 degrees), and of course, the roof is part of the living space.
We looked into how a roof like this should be constructed and read that a vapor retarder and a nail sealing tape must be used.
Here is our build-up:
On top of our spruce multilayer panels, we installed an Alujet Professional JKE underlay membrane, then the 20 mm (0.8 inch) wood fiber boards, followed by a hardwood multiplex plywood board, and then, overlapped, another layer of Alujet Professional JKE, and finally the counter battens.
We are annoyed that we didn’t receive any nail sealing tape, but maybe this is acceptable due to the use of the Multiplex plywood. What I’m more concerned about is: where exactly is the vapor retarder? The Alujet Professional JKE doesn’t seem to have that function.
We have now sent an email asking the carpenter for clarification, but I’m afraid, as often happens, we’ll just be reassured without real answers…..
Unfortunately, the roof construction is specified exactly like this in the contract…..but as a layperson, you wouldn’t know that it might be wrong…..
11ant schrieb:
That's a lie anyway, if a roof looks undamped from below after more than forty years. What exactly do you mean by that? 3-layer panels are not OSB boards and, on the contrary, look really beautiful ... 1000 times nicer than the usual boards you typically see in exposed roof structures
Snowy36 schrieb:
Here is an example Exactly – this ignores the fact that roof slopes nowadays are insulated just like the vertical exterior walls: it looks like back when insulation wasn’t used yet.
https://www.instagram.com/11antgmxde/
https://www.linkedin.com/company/bauen-jetzt/
Now, after all the disaster, here comes the best part...
First, a quick update: the manufacturer of the wood fiber boards clearly recommends a different construction method but was kind enough to perform the moisture calculation for us, and according to that, everything should be fine in terms of moisture.
But I have a roof that is probably built in a way hardly anyone else does, and I simply don’t understand what the carpenter was thinking. And I definitely don’t have any nail sealing tape, even though it should have been used.
Whether everything fits and is airtight, we will unfortunately only find out after we have done the blower door test.
But now the best part: after all the back and forth and everything that has caused us so much stress (2 weeks construction delay because of him, since he only sent 2 people; my father-in-law had to help because otherwise, the boards wouldn’t have been lifted up at all; then beams were left too long so the mason could only lay 6 cm (2.4 inches) stones instead of 11 cm (4.3 inches); and to make the insulation fit, he stuffed in perlite, which he is now charging us for).
On top of that, the builder had the crane and scaffolding standing for 2 weeks longer, and he charged for that as well.
After all this, he sends the final invoice without a word. Plus 6,000 Euros (about 6,000 dollars) more than the original quote. The main price increase is because we chose different roof tiles than in the quote.
Instead of flat tiles, we chose “reform tiles” from the same manufacturer. These are actually 6 Euro less expensive per square meter (about 6 dollars) than the others, but he simply charged us 3 Euro more (about 3 dollars) instead of 6 Euro less... which alone is almost 3,000 Euro (about 3,000 dollars). Additionally, there are items on the invoice that were not included in the original offer (providing and installing specialty roof tiles).
What options do I have now? Have you had similar experiences with change orders?
How binding is such a quote?
First, a quick update: the manufacturer of the wood fiber boards clearly recommends a different construction method but was kind enough to perform the moisture calculation for us, and according to that, everything should be fine in terms of moisture.
But I have a roof that is probably built in a way hardly anyone else does, and I simply don’t understand what the carpenter was thinking. And I definitely don’t have any nail sealing tape, even though it should have been used.
Whether everything fits and is airtight, we will unfortunately only find out after we have done the blower door test.
But now the best part: after all the back and forth and everything that has caused us so much stress (2 weeks construction delay because of him, since he only sent 2 people; my father-in-law had to help because otherwise, the boards wouldn’t have been lifted up at all; then beams were left too long so the mason could only lay 6 cm (2.4 inches) stones instead of 11 cm (4.3 inches); and to make the insulation fit, he stuffed in perlite, which he is now charging us for).
On top of that, the builder had the crane and scaffolding standing for 2 weeks longer, and he charged for that as well.
After all this, he sends the final invoice without a word. Plus 6,000 Euros (about 6,000 dollars) more than the original quote. The main price increase is because we chose different roof tiles than in the quote.
Instead of flat tiles, we chose “reform tiles” from the same manufacturer. These are actually 6 Euro less expensive per square meter (about 6 dollars) than the others, but he simply charged us 3 Euro more (about 3 dollars) instead of 6 Euro less... which alone is almost 3,000 Euro (about 3,000 dollars). Additionally, there are items on the invoice that were not included in the original offer (providing and installing specialty roof tiles).
What options do I have now? Have you had similar experiences with change orders?
How binding is such a quote?
K
Knallkörper3 Jul 2018 20:50Snowy36 schrieb:
Have you had similar experiences with additional claims?Professionally, yes, quite often. Within the legal framework, you have the following options, which I would fully utilize if you no longer need the company:
Return the invoice by mail, stating that the additional claim is not justified. You did not authorize any change to the scope of work at a higher price. Any additional costs must be reported immediately if necessary, not only after completion.
Formally report the defect in the roof structure, if that is now considered a defect. Insist on repairs within 2 weeks. Announce a retention of payment ("defect retention") in the amount of twice the repair costs if the deadline is not met.
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