Battening wall - can I chase first?

[Baseline]

Hi,

I have a wall in the bathroom looking worse for wear after removing old tiles - plaster came off too! Unfortunately I have horrible blockwork type walls (black lightweight brick 1930's house). This blockwork makes it very difficult (impossible) to remove all plaster back to brick as the blockwork comes off with the plaster. I want to batten out the walls to make it easier to renovate next time (rather than having the wall plastered with bonding only prior to tiling). The problem is if I batten out the wall I will lose too much space so what I want to do is chase the wall out around 15-20mm. The total wall thickness is approx 10CM including plaster both sides - I want to insert the battens into the chased channels so I do not lose too much space. Is this a bad idea? Would it weaken the wall too much? Channels would be 40cm apart vertically all the way up the wall.

Thanks

 

[endecotp]

Sounds bonkers to me.

The is a limit to the allowed depth of chases - I think it's 1/6 of the thcikness. Or maybe it's 1/3. Google will tell you. Whether that's still sensible if you're cutting chases over the entire wall I don't know.

 

[Baseline]

Thanks Endecotp. I think it s 1/6 for horizontal chases and 1/3 for vertical. I know it sounds a bit bonkers. Thanks again for your view. Maybe i just get plasterer to bond the wall or use dot and dab with moisture resistant boards?

 

[Baseline]

Btw the chase would be mainly in the existing weak plaster coat. Only around 5 -10mm out of the black brick...

 

[foxhole]

Just stick on plasterboard with foam board adhesive, not space lost bar the thickness of plasterboard.?

 

[L95]

Hardiebacker it over plasterboard for me personally.

 

[chris_o]

Are you putting tiles back where you're intending to board? If so, dot and dab 12.5mm cement board to the blocks, then use mechanical fixings such as concrete screws

 

[Baseline]

All of the replies are much appreciated. BTW I am going to tile the wall but this is not a wall that should get wet so why the recommendation for hardiebacker?

Having reviewed the responses and carried out a bit more research I am planning to dot and dab moisture resistant plasterboard to the wall and also use some mechanical fixings.

For the shower area I will do the same with Marmox board. Sounds ok? I might use the marmox board on the floor too prior to tiling...

The Marmox will save a lot of faffing around with tanking kits in the shower area and also waterproof the rest of the floor.

So overall bathroom walls-
1. For the wall in my original query - (Internal non load bearing wall) dot and dab + mechanical fix MR Plasterboard.
In addition for...
2. External wall - Batten and fix marmox board as it acts as an insulator too!
3. Shower area dot and dab Marmox and use mechanical fixings also

 

[chris_o]

Your plan above sounds fine. The plasterboard will be fine in a non wet area. Me being me, I would just chuck cement board at it anyway for a belt and braces approach.

What currently makes up the floor?

 

[Baseline]

Thanks Chris I'll look at using cement board all round as I don't really like the idea of tiling onto paper faced plaster board either.

The floor is currently timber floor boards very old and only about 12-14mm thick. I was thinking of removing replacing with 25mm WBP ply or 19mm ply and 6mm marmox or similar. Overkill? Or i could just put a thicker layer of Marmox over the old floor boards?

 

[chris_o]

I would personally take the old boards up as they're only fairly thin, and as you say replace them with some 18mm wbp ply. Sbr the underside and edges of ply before you put it down, then screw at 200mm intervals.

Then using a cement based flexible adhesive, set your 6mm Marmox boards on to the ply, and fix down with some screws and washers. Depending on the adhesive you use, you may need to sbr the face of the ply first too, but have a look at the manufactures instructions.

 

[Baseline]

Thanks again Chris. Sounds like a plan!

 

[chris_o]

No probs, also be sure to put extra noggins in the floor if needed before the ply

 

[Baseline]

Cheers. BTW does anyone have any recommendations re: mechanical fixings? Stainless steel screws and washers? Any particular screws or washers? Also marmox do their own fixings are the worth it?

 

[oldbutnotdead]

Stainless screws- your local favourite supplier (think I used Screwfix). Marmox washers- saw some somewhere that looked exactly the same but at a much better price, if I remember where I'll post back. And don't forget their very pricey jointing tape if you need waterproofness