sand cement internal render

[booner]

just hacked off tiles from solid shower wall, set coat has come off with tile( house is only 8 years old), render in behind i thought would be like iron(like external)!! not so, side of paint scraper can rake it back to blockwork with no effort??? is this typical of a shower wall or have plasterers used a very weak mix. will nhbc be interested in this or am i dreamin. any ideas for a remedy b4 retiling:mad2::mad2::mad2::mad2::mad2::mad2::mad2::mad2:
hmmmm, suddenly the original tiles dont seem such an eyesore after all!!!

 

[Dale44]

Sounds like browning coat and plasterer forget his finish coat.

 

[booner]

dont think so, its all sand n cement here in NI and finish has come away wiv the hacked off tiles

 

[White Room]

Some plasterers have been known to use soft sand (I've seen it) and it dos'nt have the strenght for rendering,internal or external. It could also be a very weak mix, a couple of options for you are, thin down some sbr about 4-1 and soak the sand and I mean soak which will get sucked in and bond the render when dry or rip the whole lot off and dot and dab with plasterboard. You could get hold of the nhbc but the process may be dragged out.

 

[Diamond Pool Finishers]

Some plasterers have been known to use soft sand (I've seen it) and it dos'nt have the strenght for rendering,internal or external. It could also be a very weak mix, a couple of options for you are, thin down some sbr about 4-1 and soak the sand and I mean soak which will get sucked in and bond the render when dry or rip the whole lot off and dot and dab with plasterboard. You could get hold of the nhbc but the process may be dragged out.

you dont want to use plasterboard in shower/area tile backerboard at least then tank as for wet room

 

[doug boardley]

plasterboard will be fine imo, as long as it's tanked

 

[White Room]

Ditto Doug

 

[Diamond Pool Finishers]

plasterboard will be fine imo, as long as it's tanked

im a belt and braces man myself and like to follow through from the ba cking if tanking brakesdown tilebacker will not unlike pboard up to you

 

[doug boardley]

what did you use before backerboard came along gooner?, I've been tiling for nearly 30 years and not had a problem doing it p/board and tanking. But as you say, it's up to me

 

[Diamond Pool Finishers]

what did you use before backerboard came along gooner?, I've been tiling for nearly 30 years and not had a problem doing it p/board and tanking. But as you say, it's up to me

well ive ripped out lots of showers and am forever finding that they have broken down and if pboard is used the gyipsum in it has soaked up the water and gone bad so now i never use it

 

[White Room]

People seem to think a bit of grout will hold back the water from a powershower:yikes:

 

[booner]

thanks for response people, if i screw fix mrb with, say, 60mm screws, will that suffice??

 

[doug boardley]

still tank it booner, it's moisture resistant, not waterproofI don't deny that backerboard is the best option tho'

 

[Ajax123]

Some plasterers have been known to use soft sand (I've seen it) and it dos'nt have the strenght for rendering,internal or external. It could also be a very weak mix, a couple of options for you are, thin down some sbr about 4-1 and soak the sand and I mean soak which will get sucked in and bond the render when dry or rip the whole lot off and dot and dab with plasterboard. You could get hold of the nhbc but the process may be dragged out.

I use soft sand in render quite often. You just need a higher cement content. The surface area of the smaller paricles in the soft sand need more cement to bind them. High cement content and small sand particle size leads to fantastic finish - almost as good as finish plaster. I did this as a top coat on my external walls cos I couldn't get a flat enough finish on my scratch coat. Its been there for 10 years or so and is bloomin hard.
I always use a plasticiser in the top coat as well to reduce the water cement ratio. Makes it stronger. Perhaps doesn't meet British standards but it works for me.
That said if you don't up the cement content or if you put too much water in it or if it dries out too quickly you are right it won't go hard enough.