How to sort out a raised joist..??

[pavsid]

Hi all, another "challenge" has come about - i'm nearing completion of our bathroom and will soon be laying the flooring.

But, whilst fitting the shower tray (wetroom type) i noticed that one of the joists - sods law one under the shower tray - is slightly higher than the others.

I thought that it might have become like that since i lifted and replaced the floorboards, but holding a spirit level up against the wall where the joists meet the end beam (the one running perpendicular to the joists that they are bolted on to) it looks like it has been laid like that.

So, how can I fix it, obviously that's gonna cause major issues with the wetroom, and as we're tiling it needs to be perfectly flat right?

Untitled

• pavsid
• 27 Feb 2015
• 1

Untitled

• pavsid
• 27 Feb 2015
• 1

Untitled

• pavsid
• 27 Feb 2015
• 1

Untitled

• pavsid
• 27 Feb 2015
• 1

 

[Lower]

Plane the top of the high joist or pack the tops of the others to the same level.

 

[ree]

As above. An elec plane or a Jack plane would shift that in minutes.

But, in the scheme of things i dont think that it will matter too much - it all depends on what comes next.

AAMOI: if thats a soil oversite below the joisting then why not take this opportunity to cover it with membrane? I also presume that you have good thro ventilation below the floor?

 

[pavsid]

As above. An elec plane or a Jack plane would shift that in minutes.

Hi, will planing the top off the joist require some building regs approval??

AAMOI: if thats a soil oversite below the joisting then why not take this opportunity to cover it with membrane?

It's a concrete oversite - that ok?

I also presume that you have good thro ventilation below the floor?

Yes there some wall vents under the floorboard level - why are they necessary out of curiosity?

 

[freddiemercurystwin]

Planing the joist won't be any problem and is not Building Control notifiable.

No need for a dpm on your concrete.

The vents are essential to ensure the void remains well ventilated and the joists cannot rot. There's a gap under the joists presumably?

Surprised you've not taken this opportunity to whack some insulation between the joists?

 

[pavsid]

The vents are essential to ensure the void remains well ventilated and the joists cannot rot. There's a gap under the joists presumably?

Yes there's a gap, so plenty of ventilation

Surprised you've not taken this opportunity to whack some insulation between the joists?

Dyou think it's worth it then? This is just the bathroom, there will be waterproof membrane going over the floorboards, and then tile on top.

With the vents in the wall, is there much point of installing insulation?

Many thanks

 

[pavsid]

The other problem is, when you stand on it, it does push down, although not enough for it to be level with the others.

So, is there a way I can keep it down, at least until I install the shower tray and begin tiling?

Perhaps bolting it into the concrete below?

 

[freddiemercurystwin]

Well seeing as insulation helps to retain heat then yes it would be worth it IMO. Getting out of shower and standing on freezing cold tiles in bare feet is hardly desirable.

You mean the joist bows? Or the joist is not well secured? Any movement under a shower tray and a tiled floor is very bad indeed.

 

[pavsid]

Well seeing as insulation helps to retain heat then yes it would be worth it IMO. Getting out of shower and standing on freezing cold tiles in bare feet is hardly desirable.

You mean the joist bows? Or the joist is not well secured? Any movement under a shower tray and a tiled floor is very bad indeed.

Well, I don't think it bows as such, i think it's just crowned, and lowers slightly when you stand on it. But only as far as the sleeper walls (under the floorboards) allow. So it's not as though it'll lower past the other joists.

 

[AronSearle]

For reference you can plane a little off *one* face of a joist without compromising its grade.

5mm <100mm
10mm >100mm

 

[ree]

As above.

Movement below a tiled floor is storing up potential trouble.

OP, you should plane the joist level, or compress it level with the other joists, and screw on a sistered length of 3/4" ply ripping.

Whatever, dont cover a loose joist.