Installing noggings in floor joists afterwards

[Dr Jumping Jack]

Now I'm not quite following.
All the info about laying the floor between the beams says that I need to reinforce the floor with a 13mm reinforced mass of some type. I then lower the floor by 22mm but build it up by 13mm. Not much gain when the goal is to align the wet room floor with the floor outside.
Even gvk mentions lowering the joists to 195mm but that load calculation should be present. The idea is to also attach a joist parallel to the existing one and screw-glue them to the existing joist. Shouldn't that reinforce the floor more than enough?

What other methods are there?

But if you lower the floor to 195 mm then you need a 22 mm chipboard and I guess leveling compound on top. Does that build it up enough? What will you have on the floor? Tiles?

 

[Tååmten]

But if you lower the floor to 195 mm, then you need a chipboard flooring of 22 mm and I guess leveling compound on top. Does that build sufficiently? What will you have on the floor? Tiles?

Carpet.
According to the floor installer, the floor doesn't need to be reinforced with rebar if the boards are whole on the beams. If I lower the boards between the beams, I don't get lower than 22mm compared to if the floor is on the beams, but then the rebar is needed extra with 13mm, which isn't needed if I don't lower it, so a total of 9 mm lower.
If I reduce the height of the beams to 195mm, they still maintain the necessary dimension for the floor, but the lowering becomes greater, and I come about 25mm lower. Additionally, the beams are strengthened by placing new beams parallel to the existing ones.
It won't be cc30 but double the width of beams than prescribed at cc60. I think that more than adequately compensates for any weakening that may occur from the original beams being lower.

But if anyone has a good alternative that is feasible, I'm happy to hear.
The idea to lower the floor has come from many sources, the floor installer, GVK, Säker Vatten, construction carpenters, etc. And the method suggested has been to reduce the height of the beams, or lay the floor between the beams with 13mm reinforced strengthening on top beyond what is needed for the slope...

 

[justusandersson]

All info om att lägga golvet mellan bjälkarna säger att jag måste förstärka golvet med 13mm armerad massa

The reasoning is based on using a 22 mm chipboard which is not particularly rigid. If you instead use 18 mm k-plywood, you get a completely different result. However, you need a less flexible substrate for tiles than wood, e.g., some form of gypsum board.

 

[Tååmten]

The reasoning assumes you're using 22 mm particle board, which isn't particularly rigid. If you use 18 mm k-plywood instead, you'll get a completely different result. However, you need a more stable substrate for tiles than wood, such as some form of gypsum board.

22mm particle board is correct. The floor installer didn’t suggest anything else, but we discussed whether it was worth reinforcing the floor to be able to lay tiles in the future, but he said it was an unnecessary cost because you would need to take the floor up to the particle board and then reinforce it anyway. So the options were with vinyl and particle board.

Do you mean that no reinforcement is needed if I place 18mm plywood between the joists? I understood it as if it wasn't the board but the gaps between the board and the joists that were the problem, and in that case, I don't see the difference.

 

[Dr Jumping Jack]

22mm floor chipboard is correct. The floor installer didn't suggest anything else, but we discussed whether it was worth reinforcing the floor to lay tiles in the future, but he said it was an unnecessary expense since you would need to take up the floor down to the chipboard anyway and could just as well reinforce it then. So the options were with mat and floor chipboard.

Do you mean that no reinforcement is needed if I place 18mm plywood between the joists? I understood it as it was not the board but the gaps between the board and the joists that were the problem, and in that case, I don't see the difference.

If you're going to lay tiles, you'll need joists at cc 30 cm, and you'll have to go down to the joist level to fix it, and you should probably do that now if you're planning on tiles later. If you can't lay new joists, then place short battens instead. 18 plywood is instead of 22 mm chipboard to reduce by 4 mm, everything else remains the same. The short battens with mat are just meant to support the wall.

 

[justusandersson]

The modulus of elasticity for particleboard is about 2 GPa, for plywood between 7 and 9 GPa. The difference in stiffness is therefore a factor of 4. c/c 300 applies when using particleboard. The requirements for the floor surface depend on the type of surface finish to be used. Tiles require a less flexible material such as gypsum board, leveling compound, or similar. If it only needs to be smooth, you can use masonite.

 

[Tååmten]

The modulus of elasticity for particleboard is about 2 GPa, for plywood between 7 and 9 GPa. The difference in stiffness is therefore a factor of 4. c/c 300 applies when using particleboard. The requirements for the floor's surface depend on the type of covering you will use. Tiles require a less flexible material such as gypsum board, self-leveling compound, or similar. If it just needs to be smooth, you can use hardboard.

Thank you for the answers. It will be particleboard in all cases, setting up with cc30 I think will be tricky, but the option with more noggings can be done, it depends a bit on what it actually looks like under the floor.
I have no plans for tiles at the moment, but it's better to have thought a bit ahead.

Many thanks for all the input from everyone who contributed.