ᐅ Closed ridge / open ridge – Costs for additional features

Hello everyone,

We have an upcoming appointment with the architect. To pass the time, we have had some conversations with a few general contractors.

I am quite surprised by the following statements:

1) For a gable roof without eaves, a solid knee wall must be built – additional cost $12,000
2) A raised ridge or open ridge involves much more insulation material – additional cost $9,000
3) A small T-shaped wall in the bathroom costs an extra $3,000

The first point puzzles me a lot. How is the knee wall constructed in a house with roof overhangs? We had talked about a knee wall height of around 140 cm (55 inches). Unfortunately, I forgot to ask this question during the meeting, so I am looking for an answer here over the weekend.

I find the extra charges for points 2 and 3 somewhat exaggerated, though I can understand that it generally costs more.

Unfortunately, our appointment with the architect is still some time away, so I’m trying to clarify many questions in advance.

Kind regards!

PyneBite schrieb:

1) For a gable roof without overhangs, a solid knee wall must be constructed – additional cost 12k

The load distribution vectors of the roof have different angles, so you will need a different structural calculation. A gable roof without overhangs looks sleek but is less functional.

PyneBite schrieb:

2) Ridge beam/high ridge means a lot more insulation material – additional cost 9k

It’s not just the insulation material but also a different requirement for surface finishing. For a high ceiling, I recommend acoustic panels on the ceiling. We installed Ligno Trend, but that doesn’t make it cheaper.

PyneBite schrieb:

3) A small “T”-shaped wall in the bathroom costs an extra 3k

Is it just a drywall frame or timber frame construction? With plastering and tiling? Will there be any installations inside? Does the T need to bear loads? Is it full height or does it need to stand independently? Depending on these factors, 3k can be expensive or a bargain.

Regarding point 2)
we have a quote for opening only one eave side up to the ridge, which would cost 4,500 (including raising the walls). So, 9,000 for the entire opening seems reasonable to me.

PyneBite schrieb:

1) For a gable roof without eaves, a solid knee wall must be constructed [...] We had discussed a knee wall height of about 140 cm (55 inches).

I’m not sure I understand this: a solid knee wall required only under a certain condition implies otherwise no solid knee wall; the knee wall height should be 140 cm (55 inches).

Assuming the terms are used correctly:
- then it’s unusual to have a knee wall despite a 140 cm (55 inches) knee wall height;
- assuming knee wall and Drempel refer to the same thing here—
- then the knee wall would be the same as the short external wall continuing upwards (which is always load-bearing, whether masonry or timber).

With a knee wall, the wall plate rests on it. Without roof overhangs, the wall plate not only supports the rafters, but the rafter ends also rest directly on it. The knee wall would effectively need to act as a ring beam at the same time. From “firstoffen” I gather that there is no collar beam involved here either. Please clarify what is planned in this situation.

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11ant schrieb:

I can’t make sense of this: a solid knee wall under certain conditions does not imply a solid knee wall otherwise; the knee wall is supposed to be 140 cm (55 inches) high.
Assuming the terms are used correctly)
- then a knee wall is surprising despite being 140 cm (55 inches) high;
assuming by knee wall and Drempel you mean the same thing here)
- then the knee wall would be the knee wall, meaning the extended exterior wall (which would always be load-bearing, whether masonry or timber framed).
With a knee wall, the sole plate rests on it. Without a roof overhang, the sole plate is not only the bearing surface for the rafters but these also rest with their ends on it. The knee wall would basically also have to act as a ring beam. From "firstoffen" I conclude there are no collar beams planned in this setup either. Please clarify what is being planned here.

This statement also puzzled me afterwards. I don’t know what a non-solid knee wall is either. I will follow up on this Monday.

But you could clarify now whether there is seriously going to be a knee wall and a dwarf wall connected in series here.

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https://www.linkedin.com/company/bauen-jetzt/