Scrim tape

[Barnboy]

On the installation instructions for various tile backer boards it's says to tape any joints in non wet areas with scrim tape.

Should I also put a square of scrim tape over each screw and washer or just leave them bare ? 

[crispy_wafer]

google tells me that scrim is used to bridge cracks and holes, so I'd have thought not.

[Russell griffiths]

Are you plastering it or just jointing compound on the joints. 
I’ve just had some jackoboard plastered and we fully meshed the entire board, like you would when thin coat rendering. 
it was a lighter gauge fibreglass mesh, came in 1m wide rolls. 

[Barnboy]

2 hours ago, Russell griffiths said:

Are you plastering it or just jointing compound on the joints. 
I’ve just had some jackoboard plastered and we fully meshed the entire board, like you would when thin coat rendering. 
it was a lighter gauge fibreglass mesh, came in 1m wide rolls. 

It's going to be tiled.

[Onoff]

Knauf Aqua Panel says to use a specific gun adhesive between boards...

[Barnboy]

I've used the correct Jackoboard bitumen type tape over all of the joints and screws in wet areas, the instructions say to scrim the joints outside of the wet areas, nothing is said about the screws outside of the wet areas but I thought that I'd read or heard of putting scrim tape over those screws too.

[crispy_wafer]

it cant hurt, the only inconvenience is time to do.  You are one step ahead of me...  My jackoboard is up on the wall, but I forgot to order in the membrane paint in time, so that job is having an enforced pause for the weekend. 

 

@Thorfun I remember you used jacko, did you tape over the washers and screws outside of the wet zones with scrim tape?

[Barnboy]

@crispy_wafer those were my thoughts too but thought I'd just check.

One thing for you if you've also used Jackoboard, I needed an extra layer of board to pack one wall out and swapped to Marmox as it comes in the thickness that I needed, I found that the difference between the 2 makes of board was really noticeable, Jackoboard is quite smooth and the cement layer breaks up more when cutting with a knife. 

My tiler has had me prime all of the Jackoboard with Mapei ecogrip primer as he says that he's done some testing with one of the local merchants and once tiled, adhesive and tile could be pulled from Jackoboard whereas pulling the tile frkm the Mamox and others broke the board away with the tile and adhesive.

Now that I've down this I would recommend it if you've used Jackonboard and not tiled yet, I'm swapping to Marmox for anything I now have left to do.

[Thorfun]

46 minutes ago, crispy_wafer said:

@Thorfun I remember you used jacko, did you tape over the washers and screws outside of the wet zones with scrim tape?

Not that I remember. We only used Jackoboard in the wet zones and the tiler applied a painted product as a sealer. Don’t recall scrim tape being used at all. 

[Russell griffiths]

13 hours ago, Barnboy said:

I've used the correct Jackoboard bitumen type tape over all of the joints and screws in wet areas, the instructions say to scrim the joints outside of the wet areas, nothing is said about the screws outside of the wet areas but I thought that I'd read or heard of putting scrim tape over those screws too.

Not needed, just mix up a small amount of the tile adhesive and pre fill over the screw washer dents just to bring them up flush. 

[crispy_wafer]

3 hours ago, Barnboy said:

@crispy_wafer those were my thoughts too but thought I'd just check.

One thing for you if you've also used Jackoboard, I needed an extra layer of board to pack one wall out and swapped to Marmox as it comes in the thickness that I needed, I found that the difference between the 2 makes of board was really noticeable, Jackoboard is quite smooth and the cement layer breaks up more when cutting with a knife. 

My tiler has had me prime all of the Jackoboard with Mapei ecogrip primer as he says that he's done some testing with one of the local merchants and once tiled, adhesive and tile could be pulled from Jackoboard whereas pulling the tile frkm the Mamox and others broke the board away with the tile and adhesive.

Now that I've down this I would recommend it if you've used Jackonboard and not tiled yet, I'm swapping to Marmox for anything I now have left to do.

That’s interesting and funny you say that as I purchased some big plasterboard sized abacus elements sheets from rubber duck and they were a little coarser in surface finish.

[Barnboy]

5 hours ago, crispy_wafer said:

That’s interesting and funny you say that as I purchased some big plasterboard sized abacus elements sheets from rubber duck and they were a little coarser in surface finish.

Yes the Marmox is coarser and has a honeycomb surface to it, whereas the Jackoboard is fairly smooth with just a slight ripple where the mesh is below the surface. 

Now that I've primed them with the Eco Prim  they're very gritty, you could now take the skin off of your knuckles on them.

Thanks @Russell griffiths