Backer board straight on to walls

[madeinwood]

Hi, I've got a very cold bathroom and I intend to use insulated board - maybe 20mm Marmox - underneath tiles on the exterior walls.

Am I right in thinking that I can just use tile adhesive to stick the board straight onto the (brick and plaster) wall then tile on top of it using the same depth of adhesive and method of application?

I intend to tape the seams, of course. I've also been advised to use silicon sealant in the seams before taping.

Am I okay doing this or do you see problems?

 

[DHTiling]

You will need to use mechanical fixings as well......you should be able to get them from the supplier.........i think it is about 2/3 dgrs difference you will get from the boards...might be wrong but it's about that....

 

[wetdec]

You would be easier putting in thermal plaster board on board adhesive my thinks instead of messing about m8


tiler

..

 

[madeinwood]

You will need to use mechanical fixings as well......you should be able to get them from the supplier.........i think it is about 2/3 dgrs difference you will get from the boards...might be wrong but it's about that....

Dave,

I'm not too sure what you mean here - please forgive my ignorance on this matter. What do you mean by 'mechanical fixings'? And I don't get the implications of '2/3 dgrs difference'. :stupid:

Cheers

 

[tiler burden]

mechanical fixing meaning screws/wall fixings
2/3 dgrs difference??? (you need dave for that explaination)

ed

 

[GazTech]

I'm sure Dave was referring to degrees of temperature.....Gaz

 

[DHTiling]

I'm sure Dave was referring to degrees of temperature.....Gaz

cheers gazza ..i was yes.....they can't lift the temp by that amount.... and the fixings are just either the supplied dowels or screws and special type washers........

 

[White Room]

If you go for the thermal plasterboard they will be 8x4,s and use sguare edge board, Not somethink your,ll be throwing on the roof rack of the car though.

 

[madeinwood]

Now let me see if I've got this straight......

Marmox (or thermal plasterboard) can only be fixed directly to the wall if I use a combination of tile adhesive and screw-type fixings. So I would screw through the board using a screw and a washer (presumably so as not to damage the board), into the wall. Would I need rawlplugs? I know it can be done - screw the actual screw and rawlplug into a wall at the same time, but I've never worked out how to do it myself.

And general opinion is that thermal plasterboard has the same insulating properties as 20mm Marmox? And the overall difference in temperature with either thermal board or Marmox would be a maximum 3 degrees Celsius?

Cheers:stupid:

 

[DHTiling]

check this link out..it will explain a bit better the fixing methods for some types of backer boards..... Link removed

 

[White Room]

I've have never used marmox so can't comment, If you use thermal boards and it's on an external wall what your supposed to do is seal all gaps to stop air flow between the boards and wall and around any light fixings or switchs on the wall. The point of fixing the boards to the wall is if there's a fire the backing on the boards could become dislodged and could come away from the wall. Not that your going to be in bathroom at that time, But fixing them just's make sure the boards stay put.