Garage of 11 x 8 meters - with upper floor - without pillars?

[tobbew]

Hi

I am working on the final details of the design before applying for a building permit, and it feels like I need to really figure out if our garage looks complicated.

The garage is on the basement level and above it will be the hall, kitchen, and two bedrooms.

I very much don't want any columns in the garage, so the joists need to be substantial. They can go in any direction, so I suspect the reasonable solution is to have joists that are then 8 meters long, with about 7 meters being free-hanging, so to speak.

What type of construction should be used for this? I assume regular wooden joists won’t suffice, but I can only speculate freely, such as having some smaller I-beams at regular intervals or something like that.

Thanks

 

[Matti_75]

A concrete slab perhaps?

 

[Enk Projektet]

A concrete slab perhaps?

My suggestion too...filigran maybe...

 

[kalubah]

Hang the beam in hangers from the rafters to get support without columns in the garage.

 

[tobbew]

So concrete floors then. That's not something I have any experience with. Expensive and complicated? It sounds heavy; should you also consider that when building the walls?

Hangers from the roof trusses? Since we have a floor above, would the hangers go inside the walls in that case? Or did you miss that there is a floor above?

Thanks for the answers!

 

[Mikael_L]

Concrete floor slab then. It is something I have no experience with. Expensive and complicated? It sounds heavy, should you consider that when making the walls too?

In comparison to building with wood and if building yourself, YES!.

But it is not directly complicated; concrete floor slabs are poured daily around Sweden, mostly by the big companies like PEAB and Skanska, etc., and it usually concerns office buildings, apartment buildings, industrial buildings, and hospitals, etc.

So it's not more complicated than there are many who can calculate it, and many who can perform it.

Yes, the weight becomes a bit higher, but if concrete floor slabs are being poured anyway, then it's a question of whether it's equally good to also cast the garage walls in concrete. Once all the infrastructure for a larger reinforcement and concrete job is established, the additional cost for also doing the walls isn't that serious. - I think ...

But of course, it will cost some extra bucks. But on the plus side, you get a very pleasantly substantial detached garage section, where the residential floor becomes more isolated from noise, smell, and possible fire.

 

[tobbew]

Interesting, so maybe that's the way to go. Is it Peab/Skanska that one should contact then, I wonder?

I wonder how much it would cost compared to doing it yourself. I feel like an extra hundred thousand just disappeared here...

 

[Mikael_L]

No, I don't think you should contract the big players, they're probably barely interested and certainly too expensive. But they surely hire a lot of small firms as subcontractors. And many of these small firms can certainly take on projects from private individuals.

I don't really know how you should find the right ones here. It's best to have some contacts. I know a builder here in the area, so I would just ask who they recommend. In this way, I've personally gotten in touch with a good ventilation company and excavator operators, etc.

 

[Bråkis]

I have a 6-meter span, it can be solved without columns with a 260mm kerto-beam c/c 300. With 8 meters, it becomes more difficult. Glulam 115x315 c/c 300 is an option. But not cheap. Or KERTO-S 45x400 c/c 300. Also not cheap.

 

[kalubah]

I don't know what the floor plan looks like, but it's not entirely unlikely to find some positions for hangers. A truss roof should be able to be designed to take quite a bit of load without any major problems. You might place a glulam beam in the middle of the house perpendicular to the floor joists, which can hang on a number of hangers. This would create floor joists in two sections that only span half as far. If the span isn't too long or if the building height isn't an issue, you could use a steel beam instead of a glulam beam to perhaps avoid the hangers. It's hard to say what the best solution is without seeing the plans. If you're going to lay a concrete floor, I agree with previous posts about also making the walls out of concrete when you already need to bring in another contractor.

 

[tobbew]

Ouch... The KERTO thing would cost about 75,000... Feels... Um, fantastic.

I'm wondering, if you make the form and cast it yourself, do you have to be a rocket scientist to calculate load-bearing capacity?
Tricky indeed, but I hope there's some company that is efficient and reasonably priced for this otherwise.

 

[tobbew]

I don't know how the floor plan looks, but it might not be completely unlikely to find a few places for hangers. A truss roof should be able to be designed to take quite a load without too much trouble. Ideally, you could put a glulam beam in the middle of the house, perpendicular to the floor joists, which can hang on a number of hangers. The floor joists would then be in two bays, with each spanning only half as far. If the span is not too long or if the building height is not an issue, you could use a steel beam instead of a glulam beam to possibly avoid the hangers. It's difficult to say what the best solution is without seeing the plans. If you're going to install a concrete slab floor, I agree with previous posts about also making the walls in concrete since you'll have to bring in another contractor anyway.

Hmm, yes, an interesting alternative, reasonably thought out.

Here's the floor plan we're working with.

http://www.deserveit.se/dump/ritning huset.pdf

 

[Mikael_L]

This is what the floor plan looks like, which we are working with.

I had a bit of trouble putting it together at first.
cars 5.5 meters long and 2 meters wide ...

But then I figured it out ...

 

[vilpi]

Weber has floor elements in LECA. They are available at least in 8m lengths. I don't think they are very expensive, because we bargained for them when we built.

 

[tobbew]

Mikael, it was the design software that chose for the cars to be large, but better that than having them drawn too small.

LECA floors too... Good, thanks, nice to have more options.

I have some things to think about. I won't be getting to these stages for a while, so there's a bit of room to ponder. But the slab is going to be cast in a month if everything goes as planned, after that it's not certain that anything else will be done this year, it depends a bit on how extremely complicated or expensive it gets.

The cheapest option should reasonably be to cast the floor and walls myself, but it will be a heck of a lot of work with formwork and the calculations might not be easy either. Then you order a concrete truck that dumps into the huge mold, which might even be in one big chunk with walls and holes for the doors, plus roof beams. But God knows if I dare to take on that job, even if I might get the right expertise, it will still be a lot of hard work.

Thanks for all the thoughts anyway, I hope more come so we can continue brainstorming. I've been involved and helped with some constructions, but this is the first time I'm doing anything other than a renovation for myself.