Intermediate floor

[JerreEssberg]

Do you know how deep the sewer is outside the old part? In case it dips down outside the slab so you can connect there and gain height that way.

 

[Plupp 184001]

Do you know how deep the drain is outside the old part? In case it dips down outside the slab so you can connect there and gain height that way

Unfortunately, it runs under the entire house (house from 1932). It dips first outside the house. Then we have a newly built Attefall (with heating shaft, electricity, water), geothermal pipe, new electricity and water to the garage, as well as new drainage before we reach the dipping sewage point that way... not very tempting to dig there

 

[GoC]

Then it should be easiest to install a pump well for the shower. It's a well-established and functioning solution. You can have it outside the house so that it doesn't make noise.

 

[Plupp 184001]

Then it would be easiest to install a pump well for the shower. It's an established and functioning solution. You can have it outside the house so it doesn't make noise.

I actually work at a group company that sells wastewater pumps and even though it works, I would get another well in the garden (I already have a 4000L rainwater tank) and some maintenance. But with 225 mm glulam it works, although I would prefer to reduce to 150 mm to avoid blowing down the basement the additional 75 mm.

This is how the floor level plan 1 to lower water route looks now:
32 cm joist space + parquet etc.
212 cm current ceiling height
12 cm floor drain Jafo 75 mm
2 cm extra slope
11 cm 110 ground pipe
Total: 269 cm

Planned new:
Requirement: 230 cm (likely)
269-230=39 cm left
Parquet 1.5 cm
Underlay foam 0.5 cm
Floor chipboard 2.2 cm
Joist 115*225, 22.5 cm
Slatted panel (why not OSB for example?) 2.2 cm
Plasterboard 1.3 cm
Slope on sewage pipe 4 m, 4 cm
Low-profile floor drain/shower grating rectangular 50 mm connection, 7.4 cm including tile and adhesive
Slope in shower 2 cm

That means I need to raise the shower floor 4.4 cm. Optimally, it would be to lower the slatted panel or joist 225+22 to around 210 mm and avoid raising the floor.

Gah.. perhaps I should go for prefab lightweight concrete 200 mm after all, as I can then plaster the ceiling and skip the floor chipboard. Total saving 25+22+13+22 = 82 mm.

 

[justusandersson]

Why aren't you going for 215x180 glulam beams? That is, 180 mm high.

 

[Plupp 184001]

Why aren't you going for 215x180 glulam beams? i.e., 180 mm high.

Might happen, but can't find anyone selling them? 115*225 is around 200 SEK/m. Is 215*180 double the price?

 

[justusandersson]

If you are comparing the price of glulam, it is the volume that matters. 215x180 should be about 40% more expensive than 115x225. Even if they are not in stock, all reputable building supply stores can order those standardized glulam dimensions. They also come cut to the correct length, which saves some money.

 

[Plupp 184001]

When comparing prices for glulam, it's the volume that matters. 215x180 should be about 40% more expensive than 115x225. Even if they are not in stock, all reputable building suppliers can order the standardized glulam dimensions. You also get them cut to the right length, which saves some money.

Need 34 pieces (CC300 under the bathrooms) so it will be quite a lot of money. In addition to that comes the glulam for the roof. Trying to calculate them now but it's not easy

 

[justusandersson]

You do not need c/c 300 in bathrooms. It is an industry standard (i.e., not building code) that is also expressed schematically. The desired effect can be achieved in other ways. Byggkeramikrådet is just interested in selling tiles.

 

[Plupp 184001]

Smooth program! As for the roof beam, 1 was enough. I had thought of 5...

Does anyone know what utilization rate means? Even if I exceeded 1/300, the utilization rate could be under 100%... But it doesn't add up?

Why are roofs calculated with 1/300 while intermediate floors with 1/400?

 

[largab]

Roofs are roofs, intermediate floors are floors, less deflection is important. Utilization rate is the strength. It is often the deflection that determines the dimensioning.

 

[Plupp 184001]

Roof is roof, intermediate floor structure is the floor, less deflection is important. Utilization rate is the strength. It is often deflection that determines the dimensions.

Suspected that, but then it seems strange that the program showed a utilization rate under 100% but over 1/300. But it's only the pillars for the inner wall that are at 96%, and the rest are at 30-40%. I can always go up a size just for them.

Do you know how to dimension the floor structure where the pillar is? I have the force, but it looks like a lot even if the snow load is around 0.8 kN/m2 due to the 45-degree roof and its own weight 0.9 kN/m2.

 

[justusandersson]

Most building structures cease to be useful due to excessive deflection or vibration long before they break. A utilization rate below 100% and greater deflection than 1/300 is completely normal. The vibration criterion is often most restrictive for floors on which people walk because the instantaneous deflection from a defined point load may be at most 1.5 mm regardless of the span.

 

[largab]

Suspected that, but then it seems strange that the program showed utilization under 100% but over 1/300. But it's only the pillars for inner walls that are at 96% and the rest are at 30-40%. Can always go up a dimension just for them.

Do you know how to dimension floor joists where you get the pillar? I have the force, but it seems a lot even though the snow load is around 0.8 kN/m2 due to a 45-degree roof and own weight 0.9 kN/m2.

With long beams, you get large deflection (e.g., >1/300) even though the strength is not fully utilized. If you look at a shorter beam, it's the opposite, meaning strength dimensions. Both dimensioning methods should be contained. But no one dies if you cut corners on deflection, such as the garage roof, simple conservatory. Strength is more important from that perspective (utilization as they call it).
Pillars at 96% should work. There are safety margins on these numbers. One should also consider how safe the load cases are that have been dimensioned against. Maybe try to go for a bigger size?
I would use the calculation for pillars with roof load. Make sure they are of equal height. Compare utilization and current force.
They are likely dimensioned against buckling and pressure.

 

[Plupp 184001]

With long beams, you get significant deflection (e.g., >1/300) even though the strength is not fully utilized. If you look at a shorter beam, it's the opposite, i.e., strength determines the dimensioning. Both dimensioning methods should be considered. But no one dies if you compromise on deflection, for example, garage roof, simpler outdoor room. The strength is more important from that perspective (utilization rate as they call it).
Columns with 96% should work. There are safety margins in these figures. One should also consider how safe the load cases are that you have dimensioned against. Maybe try to incorporate a larger size?
I would use the calculation for columns with roof load. Make sure they are of equal height. Compare utilization rate and actual force.
They are certainly dimensioned against buckling and pressure.

I have over 4m in ceiling height, so I can easily fit a larger one. I'm actually considering whether I should have side beams as well, but the only ones who benefit from that are the builders' merchants.

But with the column receiving about 13 kN, that force needs to be transferred to a single point on the beam below... Now I'm lucky I can have a continuous wall all the way down at that exact point, so the problem is solved. But then maybe I should reinforce with glulam 115*115 on the middle floor as well instead of 45*120 at that specific point.