Steel beam 9m span?

[attefall]

Inorganic wall constructions are, for example, built with leca (isoblock) or hollow bricks. There are superb German hollow bricks. The balcony floor can appropriately be a concrete construction of some form. Lightweight aggregate concrete or lightweight concrete. If you build a timber frame, the subfloor should be ventilated on the underside. It also fits poorly with a bad slope.

If building in steel, could you consider replacing the plywood with something else?

 

[justusandersson]

The råspont is an unsuitable material because the roof needs to be insulated. Lättbrtongelement can be laid directly on steel beams. Corrugated sheet can serve as a base for other types of concrete constructions.

 

[attefall]

Lightweight concrete elements look nice and solve some problems. However, you probably have to count on at least 200mm thickness? That together with insulation and everything else probably builds up too much for my situation :/

 

[justusandersson]

Lightweight concrete has approximately the same insulating ability as solid wood. 200 mm lightweight concrete corresponds to about 70 mm mineral wool, so you do not need to supplement with much.

 

[attefall]

Light concrete has roughly the same insulation capability as solid wood. 200 mm light concrete corresponds to about 70 mm mineral wool, so you don't need to supplement with much.

Interested in brainstorming how a full build-up with light concrete could look, from roofing felt down to the ceiling? For an amateur like me, it's a bit hard to google...

 

[attefall]

What do you think about using EPS sheets to achieve a slope on the roofing felt?
Sundolitt offers with a slope of 1:100. 30mm at the lowest point gives about 75 mm at the highest point. Could one even consider placing similar sheets on top to create a flat surface for the decking? In that way, you also utilize the slope for insulation.

 

[bossespecial]

Heights are always a problem with this type of "recessed" terraces. You want full ceiling height below and preferably the same level as the floor on the upper floor. Having a massive joist structure that is insulated on top adds a lot of height. Therefore, Koljern elements are a good solution as they save a lot of height. On this element, you then glue additional foam glass boards and slope boards (min 1:40), then a 2-layer roofing felt. The material moves very little and is very hard compared to, for example, EPS. EPS boards also need to be covered with a hard stone wool board before the paper, although I'm unsure if this is hard enough as the decking will wear the paper down. Another disadvantage is that the extension has a lot of glass, which means you may need to insulate the roof extra because of this. I would guess that's why polyurethane insulation is proposed by the designer. Unfortunately, I think it will be difficult to achieve the heights without having to have an internal step/high threshold to get out onto the terrace from the upper floor, while also having full ceiling height indoors.

 

[bossespecial]

What do you think about using EPS boards to create a slope for the roofing felt?
Sundolitt has with a slope of 1:100. 30mm at the lowest point gives about 75 mm at the highest point. Could one even consider placing the same on top to get a flat surface for the decking? That way, you also utilize the slope for insulation.

1:40 is the minimum recommended slope to meet waterproofing warranty guidelines unfortunately.

 

[justusandersson]

The idea of slope discs is excellent. Overall, it's better to have the insulation on the outside. You compensate for the slope through floor joists that need to be wedge-shaped and oriented in the direction of the slope. The major problem is creating a structural framework that doesn't steal too much in height.

 

[justusandersson]

I happily pass the responsibility to @bossespecial. He is much more knowledgeable than I am when it comes to alternative disc constructions. I think it will be difficult to meet the energy requirements in BBR for this space. One will have to come up with some formally acceptable emergency solution.

 

[attefall]

1:40 is the minimum recommended slope to meet the guidelines of waterproofing warranties unfortunately.

Does that apply even if the material supplier says otherwise? According to information, Bmi Mono PC should handle down to 1:100.

 

[attefall]

I am happily passing the responsibility to @bossespecial. He is much more knowledgeable than me when it comes to alternative disc constructions. I think it will be difficult to meet the energy requirements in BBR for this space. Some form of formally acceptable workaround will have to be found.

The building engineer at the municipality stated that it was OK as long as the average for all surfaces is below U 0.4 in the extension, even though the roof exceeds 0.13.

 

[bossespecial]

I happily pass the responsibility to @bossespecial. He is much more knowledgeable than I am when it comes to alternative disc constructions. I think it will be difficult to meet the energy requirements in BBR for this space. A formally acceptable emergency solution needs to be found.

No, no, everyone should be included I apologize if I seemed short, two screaming children, dinner, tooth brushing, bedtime, writing as much as I can without breathing.

 

[bossespecial]

Does that apply even if the material supplier says something else? According to information, Bmi Mono PC should handle down to 1:100.

Yes, they have products that can handle very flat roofs. However, they do not take responsibility for the remaining construction. A small deflection and you have standing water. Those I am in contact with recommend the guidelines of waterproofing guarantees as far as possible.

 

[bossespecial]

The building engineer at the municipality said it was OK as long as the average for all surfaces is under U 0.4 in the extension, even though the roof ends up over 0.13.

Perfect, then you have received a value from the municipality at least Do you know which glass sections you are going to buy yet?