Bathroom Wall Against Chimney

[Hellan10]

Hello
What do today's regulations say? Can you use 70mm wooden studs against a chimney breast or are 70mm steel studs required, and what distance should there be from the chimney breast?

Can you leave 45mm and have mineral wool as the material in between? The interior wall will be a tiled wall in the bathroom. Studs spaced at 450mm centers.

Then the eternal question if 15mm plywood + drywall is required?

 

[Claes Sörmland]

Is the chimney used such that a flue is facing the bathroom wall? Then there are fire safety considerations to take into account.

In that case, you should essentially not cover it with partition walls because you won't be able to see if the chimney leaks or has cracks. So, it's best to use a solid construction like plaster on which you can apply, for instance, waterproofing and tiles.

But I believe there are an endless number of bathrooms (especially in old apartment buildings) that do not follow this rule, and fire inspectors often overlook it.

 

[Hellan10]

Is the chimney used so that a flue channel is outermost against the bathroom? Then there are fire safety considerations to take.

In that case, you should not, in principle, build over it with shell walls because then you cannot see if the chimney is leaking or has cracks. So it is best then a solid construction with, for example, plaster on which you apply, for example, a waterproof membrane and tiles.

But I think there are an infinite number of bathrooms (not least in old multi-family houses) that do not follow this rule and the fire safety inspectors turn a blind eye.

Thanks
Yes, a channel is against the “new” wall. Reading different answers everywhere so I humbly welcome all suggestions but maybe it's best to check with my chimney sweep what he says.
I haven't started the wall yet and don't want to do more than necessary but of course follow current regulations.

 

[Claes Sörmland]

Ping @vinylskiva who in the neighboring thread just admitted that he knows something about the subject.

 

[vinylskiva]

10cm is practice. If you can place a steel rule closest, do it, take some pictures of how you are building the wall in case there is a question mark later on.

 

[basseman]

If possible, insert a stainless steel duct into the used channel, so you don't have to worry about whether the masonry is tight.

 

[Huddingebo]

In my house, there is a narrow shaft between the chimney and the bathroom.
It can be inspected from below from the basement.

No words about it during the fire safety inspection last summer.

 

[Claes Sörmland]

In my house, there is a narrow shaft between the chimney and the bathroom.
It can be inspected from below from the basement.

Nothing was mentioned about it during the fire safety inspection this summer.

But then it can be inspected, so no problem!

What you often want to do is build over the chimney so it can't be inspected. Then there might be a discussion at the next fire safety inspection.

(I had to drill a 100 mm inspection hole when I built over the chimney. Some fire safety inspectors look in, but most don't care. During a pressure test of a channel, they looked in.)

 

[Hellan10]

Thank you so much for all the answers, then we'll build with steel studs and leave 100mm. In the worst case, it's possible to drill a hole from the basement to access and inspect this 100mm space then.

Thank you!

 

[Jenpet]

In a previous 1920s house I had, the brick chimney stack went up through the newly built bathroom on the upper floor. On the ground floor, I set up a tiled stove. I simply tiled the chimney stack in the bathroom and put up towel hooks, which gave me an excellent towel warmer and a warm, cozy bathroom for the morning shower since the chimney stack stored heat from the night before.

 

[Hellan10]

In a previous 1920s house I had, the brick chimney flue went up through the newly built bathroom on the upper floor. On the ground floor, I installed a tiled stove.
I simply tiled the chimney flue in the bathroom and put up towel hooks, which meant I got an excellent towel dryer and warm and cozy bathroom for the morning shower since the flue stored the heat from the previous evening.

Yes, that also sounds interesting.. hmm, you didn't make it any easier for me.

 

[Jenpet]

Yes, that also sounds interesting.. hmm you didn't make it easier for me.

Ha ha... on the contrary. Much easier, you don't have to think about studs and inspection hatches . Additionally, you get a "heat wall" if you have a fireplace/tiled stove...

 

[Claes Sörmland]

Yes, that sounds interesting too... hmm you didn't make it easier for me.

If you don't like plastering the chimney because it's technically too difficult for an amateur to get it perfectly flat, you can also "glue" drywall with intended mortar. Then waterproofing right on top and then tiles. Now you have a solid wall all the way to the chimney and it meets fire protection requirements and wet room requirements.

 

[Utsliten och utdömd]

If you don't like the idea of plastering the chimney because it's technically too difficult for an amateur to get it completely flat, you can also "attach" drywall using appropriate adhesive. Then apply a waterproof layer directly on it followed by tiles. Now you have a solid wall all the way to the chimney that meets fire protection and wet area requirements.

That's what we did. We brought in a chimney sweep for advice beforehand. Plastered the chimney completely vertically, but quite roughly, with lime plaster and then adhered drywall with Ardex s48, waterproof layer, and tiles.

 

[Claes Sörmland]

This is how we did it
Hired a chimney sweep for advice beforehand.
Plastered the chimney completely vertically, but rather roughly, with lime plaster and then glued up drywall with ardex s48, waterproofing, and tiles.

Nice! Solid constructions are always the best in these contexts.