Hello everyone!
I am about to renovate my bathroom, and according to the new regulations, I need to level with a slope resulting in at least 17mm of leveling compound and then up to 25mm.
Since this will be happening on the upper floor, I'm a bit concerned about the weight it will put on the beams.
The beams are 220*45 and I'm a bit uncertain about the length since I don't have a blueprint, but I would guess around 5m.
What do you think about the weight?
Perhaps I should mention that the total floor area is about 5.5 sqm and the beams are spaced 60cm apart.
I am about to renovate my bathroom, and according to the new regulations, I need to level with a slope resulting in at least 17mm of leveling compound and then up to 25mm.
Since this will be happening on the upper floor, I'm a bit concerned about the weight it will put on the beams.
The beams are 220*45 and I'm a bit uncertain about the length since I don't have a blueprint, but I would guess around 5m.
What do you think about the weight?
Perhaps I should mention that the total floor area is about 5.5 sqm and the beams are spaced 60cm apart.
A floor structure is typically calculated for dead load + live load. The first being permanent. The second not being permanent. The live load in residential buildings is set to 50kg/m^2 in a uniformly distributed load under normal conditions and can be increased by 40% under exceptional load (e.g. when water is in the bathtub). Additionally, there is mobile load (which is always considered a point load, equivalent to two adult people in the most hazardous load position, i.e., in the middle of the floor).
A bathtub (if present) with water weighs a lot, but it usually doesn't stand in the middle of the floor, and there usually aren't any other furniture in the bathroom apart from the toilet. Hopefully, the designer has already considered the bathtub since it becomes a point or possibly a line load relative to the beams and sized accordingly. In other words, the rest of the uniformly distributed load is absent.
You can therefore use part of the distributed live load for floor covering without anything happening.
You should calculate how much the tiles, grout, and the substrate you're building with weigh together/m^2 and see how much you have left of the standard 50kg/m^2.
But... if you will tile on a wooden beam floor, you get another problem instead, related to the load. It's the risk of deflection in the wooden structure, and the beam dimensions might not suffice even if they handle the load. Deflection increases with increased load, and even with moderate deflection, you risk the tiles detaching from the substrate, or the grout crumbling under pressure during a change in angle, or they might crack and break off. This is commonly referred to as 'floor bounce'. Therefore, try jumping heavily on the floor right now. If it already feels flexible, then choose another floor covering.
________________
The Builder
A bathtub (if present) with water weighs a lot, but it usually doesn't stand in the middle of the floor, and there usually aren't any other furniture in the bathroom apart from the toilet. Hopefully, the designer has already considered the bathtub since it becomes a point or possibly a line load relative to the beams and sized accordingly. In other words, the rest of the uniformly distributed load is absent.
You can therefore use part of the distributed live load for floor covering without anything happening.
You should calculate how much the tiles, grout, and the substrate you're building with weigh together/m^2 and see how much you have left of the standard 50kg/m^2.
But... if you will tile on a wooden beam floor, you get another problem instead, related to the load. It's the risk of deflection in the wooden structure, and the beam dimensions might not suffice even if they handle the load. Deflection increases with increased load, and even with moderate deflection, you risk the tiles detaching from the substrate, or the grout crumbling under pressure during a change in angle, or they might crack and break off. This is commonly referred to as 'floor bounce'. Therefore, try jumping heavily on the floor right now. If it already feels flexible, then choose another floor covering.
________________
The Builder
I'm no expert, but I talked to a tile guy a while ago and he absolutely recommended spacing 300 mm on center when tiling, precisely to reduce the risk of cracks due to flex. I even think he said there were requirements for it. Additionally, the maximum length for a 45x220 without support is around 4.2m with normal deflection tolerance, according to our engineer, so it sounds like you might have issues with a shaky floor.