Sealing screw holes in marmox

[divorcingjack]

Just had a bit of a puzzling conversation with marmox technical - although not the actual technical guy, he was on his lunch... 

 

I was asking what the best thing to do is in order to seal the fixing holes in the marmox boards in the wet shower area. He suggested using cut up squares of the (really quite outrageously expensive) marmox waterproofing tape. There's quite a number of fixing points, this seems a bit mad, and the tape appears to be quite thick. I was patronisingly told "well, if you want it to be waterproof...." 

 

Now, I will buy the tape if that's what's required. But - can't I use a waterproof sealant/adhesive type thing? We are fitting ditra matting to the floor and I'll have to buy the kerdi Keba and Kerdi Coll adhesive (https://www.tilefixdirect.com/product/SHKERDI-COL?gclid=EAIaIQobChMIxtWFpteB4QIVyRnTCh0zng7VEAAYASAAEgJe1vD_BwE) to join those sheets anyway. Can I use the kerdi coll on the screw holes? CT1? 

 

Cheers!

 

 

Edited March 14, 2019 by divorcingjack

[nod]

The correct answer should of been

I don’t know 

I’m the guy who makes the tea 

 

If you are tanking the walls simply paint over the fixings holes 

I generally tile straight over them with a good quality bagged adhesive 

 

There are all sorts of new tiling products coming out Sometimes I haven’t the foggiest why I’m painting them on Just that they are on the spec 

 

Hope this helps 

 

[nod]

1 minute ago, nod said:

The correct answer should of been

I don’t know 

I’m the guy who makes the tea 

 

If you are tanking the walls simply paint over the fixings holes 

I generally tile straight over them with a good quality bagged adhesive 

 

There are all sorts of new tiling products coming out Sometimes I haven’t the foggiest why I’m painting them on Just that they are on the spec 

 

Hope this helps 

 

Ps

 

id your sticking Ditra to a timber floor There is no better adhesive than Ardex 

Flexable adhesive to screed 

(standard set )

[divorcingjack]

Hiya, 

 

We're not tanking the walls as the marmox boards themselves are waterproof, it's just the screw holes and joints that need sealing, hopefully! Ditra is going down on the concrete slab, but I'll defo look at ardex. We need a specific adhesive, I think that'll work with limestone, but I'm sure Ardex will make something suitable. 

 

 

[Mr Punter]

I have found limestone is a PITA to keep clean. Have you looked at the porcelain alternatives?

[SiBee]

Hi,

I know from reading that Nod knows his stuff and not wanting to step on any toes here but why not do as I have done in the past. Since you are using Marmox boards why not use their own multibond sealant? Its fully waterproof and made for this. I am sure their installation guides show that boards butting up or meeting at corners should be sealed with this stuff so why not screw holes. Thats how I have used it. Also good for sealing around the sink and bath as it stays white, unlike some I have used that guarantee to but fail.

Just a thought.

 

Simon

[nod]

2 hours ago, divorcingjack said:

Hiya, 

 

We're not tanking the walls as the marmox boards themselves are waterproof, it's just the screw holes and joints that need sealing, hopefully! Ditra is going down on the concrete slab, but I'll defo look at ardex. We need a specific adhesive, I think that'll work with limestone, but I'm sure Ardex will make something suitable. 

 

 

Marnix are really good boards 

We often use them straight onto caba decking 

If the floor is uneven bed tgem fown with a bagged adhesive to straighten the floor 

Then drive 32 mil screws in at 300 centres the following day 

 

you won’t have any issues if you tile over the fixings It’s unlikely that any moister will get through the waterproof adhesive 

 

If you are using limestone 

Don’t forget to seal them before grouting and sort through the packs prior to starting So as nor to have clusters of dark and light together 

 

[divorcingjack]

2 hours ago, Mr Punter said:

I have found limestone is a PITA to keep clean. Have you looked at the porcelain alternatives?

 

I have, but just not found anything I love as much. It’s a Jura grey limestone with loads of fossils in. Much denser than “regular” limestone so hopefully should be lower maintenance. 

[divorcingjack]

2 hours ago, SiBee said:

 Since you are using Marmox boards why not use their own multibond sealant? Its fully waterproof and made for this. I am sure their installation guides show that boards butting up or meeting at corners should be sealed with this stuff so why not screw holes

 

Hi Simon, 

 

TBH that was my other thought, I just didn’t want to be bothered buying yet ANOTHER thing (as I have approximately 11 billion things still to order for the build) if the Kerdi would do the job. Good to know I could make use of it elsewhere too though. 

[nod]

1 hour ago, divorcingjack said:

 

I have, but just not found anything I love as much. It’s a Jura grey limestone with loads of fossils in. Much denser than “regular” limestone so hopefully should be lower maintenance. 

I’ve recently done a floor and loos in a large hotel Just short of 500 sq mtrs I would imagine it will take more abuse than yours 

Limestone is still quite popular 

Bug as I’ve already stated 

Sealing it is crucial 

I buy Easy seal by the bucket load 

Chesp and as good or better than all the sealers that come in tiny bottles and a hefty price tag 

 

[SiBee]

Just spoke to a tiler mate and he just skims over screw heads with the water proof adhesive and let’s that go off before he applies the tile addy bed. He takes out wall imperfections within reason the same way. Presuming it’s walls and boards are solid.

i know what you mean about using what you already have, makes sense as somethings you have will be more than up to this job.

Two things he keeps telling me, grout is not water proof and don’t use charcoal-black