How to get boards straight on a wavy wall?

[Enk Projektet]

Start by installing blocks/spacers where needed, if you have a long straightedge and a spirit level, you can quickly measure where it needs to be built out.
Then you install 15mm plywood behind the wet room panels, this should give very flat walls.

I believe this is the simplest and quickest way to achieve a good (straight) result.....

 

[Lolle]

stoif: Of course, there are still those who use shrinking, loosening plastic mats as a waterproofing membrane in the shower today, and if you do, you should probably glue the details that need to be mounted on the wall. GVK constantly changes its regulations. A few years ago it became completely prohibited by the Building Authority to use cardboard-based gypsum in wet rooms.
I have seen countless wet rooms with mold-infected gypsum, especially at fasteners.

Hold on, GVK has never banned cardboard gypsum, however, BKR does it after some fuss and internal lobbying. It should be added, though, that this prohibition is not based on pure damage statistics, but rather contrary to that, it is not a problem with wet room foil, especially since they have been approved under ETAG 022.

Initially, you could continue with cardboard gypsum if you built according to GVK, as almost all suppliers allowed this. Slowly but surely, most suppliers backtrack after pressure and change their installation instructions, so in practice, it is becoming difficult to build with cardboard gypsum.

In terms of damage with mold growth, you of all people should know that there are no reported cases where the waterproofing membrane was not faulty.

 

[injonil]

And speaking of Boverket: http://www.boverket.se/kontakta-oss...r-jag-anvanda-papperkladd-gips-i-mitt-badrum/

 

[seniorkonsult]

I think it's you who have no clue. Read AMA and older Boverket regulations. I am an inspector and responsible for control for many years, so I definitely know my stuff.

 

[injonil]

Could you then show where in Boverket's regulations it prescribes våtrumsgips? There are plenty of inspectors and responsible controllers without a clue...

 

[Lolle]

I think it's you who have no clue. Read AMA and older Boverket regulations. I have been an inspector and responsible for quality control for many years, so I certainly know what I'm talking about.

As mentioned, it is approved and always has been according to GVK, while BKR instituted a ban on it. However, there are also internal discussions within BKR about revising the requirement again, but as always, money is involved. However, GVK requires that the waterproofing supplier's instructions be followed, which disqualifies plasterboard in many cases.

Neither Boverket nor Building AMA have any direct bans.

 

[seniorkonsult]

In terms of damage related to mold growth, you, of all people, should know that there are no reported cases where the waterproofing layer was not faulty[/QUOTE]
Yes, there are countless cases which the insurance companies surely are aware of. The tile grout allows water to pass through, and this moisture travels through the waterproofing layer into the board. This was what started the debate about cardboard-covered gypsum board in wet rooms (zone 1).
Now I'm talking about the older waterproofing layers that have lower vapor resistance.

From Byggutbildarna 2012.
Several years ago, SP, Sweden’s Technical Research Institute, cautioned that several liquid-based waterproofing systems did not have a sufficiently high vapor resistance to meet the recommendations in BBR or to avoid moisture damage. The research results led to changes in both industry standards and practice.
According to the new industry standards from the Building Ceramic Council, BKR, the waterproofing in the wettest wet zone must consist of a folio system for walls and floors on board constructions. SP tested five common waterproofing systems under ceramic tiles in wet rooms. The manufacturers were not specified. All five tested folio systems leaked, some more than others. However, it should be possible to make them watertight with the correct installation and proper seam technique.

 

[Lolle]

Damage-wise with mold growth, you should of all people know that there have been no found cases where the waterproofing was not faulty

Yes, there are countless cases, which insurance companies surely are aware of. The tile grout allows water to pass through, and this moisture travels through the waterproofing into the board. This was what started the debate about paper-faced gypsum in wet areas (zone 1).
Now I'm talking about the older waterproofing systems that have lower vapor resistance.

From Byggutbildarna 2012.
Several years ago, SP, the Swedish National Testing and Research Institute, warned that several liquid-based waterproofing systems did not have a sufficiently high vapor resistance to meet the guidelines in BBR or to avoid moisture damage. The research findings led to changes in both industry regulations and practice.
According to the new industry regulations from Byggkeramikrådet, BKR, the waterproofing in the wettest wet zone should consist of a membrane system for walls and floors on board constructions. SP tested five common waterproofing systems under ceramic tiles in wet rooms. The manufacturers were not indicated. All five tested membrane systems leaked, some more than others. However, it should be possible to make them watertight with the right implementation and seam technique.[/QUOTE]

Yes, insurance companies have a good handle on this, some of them at least. I have a pretty good knowledge of the reported damage statistics to the Wet Room Council from all major companies. With the old rolled waterproofing, there is a large pile of damage reports on mold growth on paper-faced gypsum, but not a SINGLE one of these damages had a correctly executed waterproofing. Instead, they found too thin waterproofing, missed gaskets installation, etc.

When looking at the additional costs in the damages, these were statistically almost negligible. Sure, there was mold growth, but no or minimal spread otherwise, and even without this growth, the boards would have needed replacement.

 

[seniorkonsult]

Here is a test report. Download it and search for "gipsskiva". An interesting and frightening read.

http://uu.diva-portal.org/smash/get/diva2:562733/FULLTEXT01

It's about tile cladding and..floor drains.
As for the insurance companies, they require moisture-resistant boards, which cardboard gipsskiva can hardly be called. I would never install a gipsskiva in my bathroom regardless of waterproofing.

 

[Lolle]

It should be noted that the foil systems have been replaced and tested under etag 022 since the SP test. Additionally, the tests were deliberately escalated by us in the order to determine the tightness in a "worst case" scenario.

 

[vectrex]

Sure, there are countless cases that insurance companies probably keep track of. The tile grout lets water through, and this moisture travels through the waterproofing into the board. This was what started the debate about paper-covered gypsum in wet rooms (zone 1).
Now I'm talking about the older waterproofing that has a lower vapor resistance.

From Byggutbildarna 2012.
Several years ago, SP, the Swedish National Testing and Research Institute, warned that several liquid-based waterproofing systems did not have sufficiently high vapor resistance to either meet the advice in BBR or to avoid moisture damage. The research results led to changes in both industry regulations and practice.
According to the new industry regulations from Byggkeramikrådet, BKR, the waterproofing in the wettest wet zone should consist of a foil system for walls and floors on board constructions. SP tested five common waterproofing systems under ceramic tiles in wet rooms. The manufacturers were not specified. All five tested foil systems leaked, some more than others. However, it should be possible to make them tight with the right execution and correct seam technique.

It's alarming how many inaccuracies people spew out left and right, no wonder people are afraid to create their own wet rooms. In my opinion, it is no harder than choosing BKR or GVK and then following their instructions to the letter.

Moreover, I am 100% convinced that a liquid-based waterproofing system applied in the correct amount does not let through moisture in vapor form to such an extent that mold would start to grow on drywall. There is not a chance. It would otherwise be in some extreme case where the drywall is enclosed in a poorly insulated exterior wall between a vapor barrier and a liquid-based waterproofing.

The big problem with the liquid-based waterproofings as I understand it was that it was so easy to cheat by not applying a sufficient amount. Not that the vapor resistance was too low when the work was done correctly!

 

[tlundberg]

I am in the process of converting a former bedroom into a bathroom. All the walls have been torn down to the tongue and groove boards... The dilemma is that the boards are slightly warped after their 50 years in construction.

I'm in exactly the same situation at home, though I'm just making a bedroom, not a bathroom. But no matter what you do, it's nice to have straight walls

Start by mounting blocks/spacers where needed, if you have a long straightedge and a level, you can quickly measure where you need to build out.

I use masonite strips and paint mixing sticks as spacers, and then I use battens 23x36mm to avoid building too much, but still accommodate VP pipes. If I didn’t need to run pipes, I could have mounted the OSB directly against the tongue and groove/spacers.

It's a bit finicky, but it works. I have a 2m straightedge and a 120cm level.

 

[mångstekta]

Don't know how you do it, but I don't use filler to attach tiles on walls!

Filler and adhesive (for tiles) for wet rooms are not the same products.

but read what I wrote before you comment then!! "fix" is quite often what you call the stuff you use to set tiles (that is adhesive), but curing filler is like ardurapid or other fast-curing "concrete filler" don't really know how that's classified! But it is guaranteed to be stronger than "adhesive/tile fix"...

 

[seniorkonsult]

It's alarming how much misinformation people spew left and right, no wonder people are afraid to build their own wet rooms. In my opinion, it's no harder than choosing BKR or GVK and then following their instructions to the letter.

I am otherwise 100% convinced that a liquid-based membrane system applied in the correct amount does not let moisture through in vapor form to such an extent that mold would start to grow on drywall paper. There's no chance. It would only be in some extreme case where you have enclosed the drywall in a poorly insulated exterior wall between a vapor barrier and a liquid-based membrane.

The big problem with the liquid-based membranes, as I understand it, was that it was so easy to cut corners by not applying a sufficient amount. Not that the vapor permeability was too low with properly performed work!

It's not about cutting corners. It's about tested products that are proven not to be impermeable according to the requirements 1000 000s/m. Hence, mold develops in the paper on the drywall because the joints are not watertight.

 

[injonil]

senior consultant, I don't know if it's particularly meaningful to discuss with someone who can't admit a mistake.

You wrote that drywall was not allowed in wet rooms (i.e., regardless of zone) and referred to Boverket. Boverket only provides answers on function, not technical solutions, and instead refers to industry standards, so we can’t possibly find anything about drywall at Boverket. GVK allows drywall with the right waterproofing outside zone 1, so you're wrong. There are many here on the forum with very good knowledge of the regulations regarding wet rooms, and until you admit how it stands, you probably won't gain much trust here, whether you work as an inspector or not.