Alternative floor construction (timber frame, spaced, double plasterboard)

[MathiasS]

I have encountered some problems when constructing a subfloor.

The floor structure is timber joists cc30, 21x120 sparse paneling, double floor gypsum glued with Ardex S48. On this lies tile. This construction is okay in all ways, but for some reason, we did not foresee that there would be a problem when the floor goes over the load-bearing wall in the middle of the house. It's quite obvious really since the old floor joists have some sagging between the support points (outer basement walls + the load-bearing wall). Consequently, there is a high point directly over the load-bearing wall, and it's not possible to lay the second layer of gypsum.

You don't have to be a rocket scientist to figure out that there will be problems, but here we are anyway.....

I have the following suggestion for a solution - what do you think about this:

All gypsum is laid as usual (first layer screwed, second glued) except the gypsum board that "teeters" on the load-bearing wall. This is replaced with self-leveling compound, Maxit ABS317 in about 14mm thickness (board thickness + S48). Then the tile is laid on this as usual. It involves just over a square meter that needs to be leveled in an elongated shape.

I believe this construction is as strong (or stronger) than the gypsum construction?
Should the compound be reinforced (I don't think so)?
Other opinions?

A completely different alternative is, of course, to make a joint in the floor at the high point, but I would prefer to have an unbroken floor.

What does the collective intelligence of the forum think about this? :-/

 

[sigpl]

I would, without hesitation, do as you suggested yourself. Add reinforcement anyway so you can sleep well at night

 

[MathiasS]

Just talked to Maxit and we also agree that it will be a good construction. I might add some armeringsnät as well, but it seems to be overkill.

 

[Alsti18]

Off topic but you, MathiasS, usually know... why do you have double gypsum - is it because you have 120x21? Can I put single floor gypsum on a floor with underfloor heating c-c 30 on sparse 120x28 and joists c-c 60? Hall floor with tiles. That's what I've convinced myself of so far, but there's still time to change... I think I've seen this in a thread somewhere but it's hard to find among everything...

 

[MathiasS]

Off topic but you MathiasS usually have knowledge...why do you have double gypsum - is it because you have 120x21? Can I put single floor gypsum on a floor with underfloor heating c-c 30 on sparse 120x28 and joists c-c 60? Hall floor with tiles. That's what I have imagined, so we have started from that, but there is still time to change...I think I've seen this in some thread but it's hard to find among everything...

If you look at Wirsbo's installation principles, they say cc60 joists, sparse paneling, chipboard, one layer of gypsum.

I didn't want chipboard on top of the pipes and therefore made an alternative construction (which Wirsbo also thought was okay). Joists cc30, sparse paneling, double glued gypsum. No chipboard.

I don't know if you are allowed to lay just one layer of gypsum on sparse without chipboard in the construction.

If you still want chipboard, I would lay it directly on the joists (glue and screw).

Johan G on the forum has also made an interesting solution. Chipboard on the joists, then fine concrete over the whole deal. Low building height, perfect heat conduction. Johan might be able to give you more details about this.

 

[Alsti18]

Yes, but 28 is more than sufficient for a load-bearing floor, should you really need double gypsum or particleboard? With 21 it's a different matter. The small gap that occurs with 120 width on c-c 30 is in my opinion negligible...

 

[MathiasS]

Yes, but 28 is more than adequate for a load-bearing floor, should you really need to double plasterboard or chipboard then? With 21 it's a different matter. The small gap that forms with a width of 120 on c-c 30 is, in my opinion, negligible...

That's precisely the home DIYer's dilemma. When you're unsure, you should go a bit further to be completely certain. Considering that Wirsbo wants a chipboard there, you should probably do your best to replace it...

 

[Tompa01]

If you look at Wirsbo's recommended installation principles, they say cc60 joists, furring strips, subflooring, one layer of gypsum.

I didn't want subflooring on top of the pipes, so I made an alternative construction (which Wirsbo also thought was okay). Joists cc30, furring strips, double glued gypsum. No subflooring.

Why no subflooring? Does the gypsum conduct heat better, or is there another reason?

Tompa

 

[MathiasS]

[quote author=MathiasS link=1137614568/0#4 date=1137677289]

If you look at Wirsbo's recommendations for installation principles, they suggest cc60 beams, sparse paneling, chipboard, a layer of plasterboard.

I didn't want chipboard over the pipes and therefore made an alternative construction (which Wirsbo also thought was okay). Beams cc30, sparse paneling, double glued plasterboard. No chipboard.

Why no chipboard? Does the plasterboard conduct heat better, or is there another reason?

Tompa
[/quote]

Rather an extra layer of plasterboard than 22mm chipboard - right or wrong, that's how I've reasoned. Partly in consideration of heat conduction, partly the build height. 1 centimeter is important when renovating a house..... :=)