Installing a Wedi fundo shower base and the instructions
Installing Fundo in Wooden Floors 2 say to fill around the drain with a 'semi-dry sand/cement mix'. Would this be in a ratio of 4:1 and how dry is 'semi-dry', hold itself together without feeling wet? Also how long after applying it can I fit the base, 24 hours?

Originally Posted by aflemi

Installing a Wedi fundo shower base and the instructions
Installing Fundo in Wooden Floors 2 say to fill around the drain with a 'semi-dry sand/cement mix'. Would this be in a ratio of 4:1 and how dry is 'semi-dry', hold itself together without feeling wet? Also how long after applying it can I fit the base, 24 hours?

I would make the sand cement like screed once mixed grab a hand full and squeeze it in you hand and then open the mix should stay bonded togeather and your hand should be damp and not soaking wet, this will make it easier to compact it around the drain, you can then fitt the board over the top and level it off strait away. a mix ratio of 3-1 is what i would do but others may reply with a different mix ratio.

Originally Posted by peckers

I would make the sand cement like screed once mixed grab a hand full and squeeze it in you hand and then open the mix should stay bonded togeather and your hand should be damp and not soaking wet, this will make it easier to compact it around the drain, you can then fitt the board over the top and level it off strait away. a mix ratio of 3-1 is what i would do but others may reply with a different mix ratio.

Cheers. Does the sand/cement not need to dry then the former is fixed to it with adhesive? the top of the sand/cement should be level with the flooring boards, no?

Originally Posted by aflemi

Cheers. Does the sand/cement not need to dry then the former is fixed to it with adhesive? the top of the sand/cement should be level with the flooring boards, no?

Appologies i thought you was asking about putting the flooring overe the drain and cementing in!

The cement should be dry before you stick the former down over the top of the drain. so the adhesive sticks to it. I am unsure how long to wait for as it depends on how long it takes to dry! you could buy a small bag of rapid set cement which should be dry enough in 24 hrs!
Hopefully someone else with more knowledge on the cement drying times will be able to comment!

Semi dry is one of those unfortunate building terms which is completely ambiguous. Some people like their screed quite wet others very dry. As Peckers says the standard test on site is top grab a handful and squeeze it together. You should be able to compact it and it holds itself together without being too plastic. 3:1 will be stronger obviously than 4: 1 but it will also shrink more. Not a major issue if only bedding in a drain cos you only using very small quantity.

As for the length of time before sticking the former down I will leave the tilers to answer that.

cheers, guys. Anyone out there have a view on safe time to apply adhesive over?

i would say ,a couple of day's mate and I'd also use a 3-1 mix like peckers

Originally Posted by gooner59

i would say ,a couple of day's mate and I'd also use a 3-1 mix like peckers

Cheers, on the Wedi instruction video, they don't even mention a drying time, just fire ahead and lay on the former, think I'll get some rapid drying cement in the morning and it should help.

Many formers need support you may save on the board but pay on the labour and messing around. Foam cored wetroom formers in wood floors, suport the trap my ar$e.

You get what you pay for, simple fact in this business do it once do it right !!!!!!


.

Originally Posted by wetdec

Many formers need support you may save on the board but pay on the labour and messing around. Foam cored wetroom formers in wood floors, suport the trap my ar$e.

You get what you pay for, simple fact in this business do it once do it right !!!!!!


.

Sorry, not sure what your point is here, my friend.....

he is just grumbling foam core formers mate!!

Yes, thought 'wrong side of bed' moment......................
Thing is , I don't think wedi is cheap but if installed correctly has good reputation.

1:3 by weight,you need the screed to gain strengh in warm conditions a week to be safe.

Originally Posted by floora

1:3 by weight,you need the screed to gain strengh in warm conditions a week to be safe.

Even with rapid setting cement?

only sets quick hardeding might take longer

Aflemi, what did you end up doing with your project? I haven't installed a Wedi fundo tray but it looks interesting.

I used quick drying cement in the mix, figured that the area involved was actually pretty small, only a box surrounding the drain so max width prob only 60 mm or so. I left it a day before laying fundo and it's been tiled and grouted, will post pics when all done. To be honest it's the first wet-room former I've done so nothing to compare it with but I liked using the fundo, feel confident all will be watertight.

I look forward to seeing your pics.

Sand and cement screed curing time for tiling is usualy dependant on thikness of screed. I would go for 4:1 ratio, a rough guide for time is 1 day per mm. I know this is not always practical but what is?

Originally Posted by Phil Hobson

Sand and cement screed curing time for tiling is usualy dependant on thikness of screed. I would go for 4:1 ratio, a rough guide for time is 1 day per mm. I know this is not always practical but what is?

Not sure an 80 day interval in the process of laying a wet room floor is going to work for anyone...............

def not practical,
For up to 50 mm in the area/ temp i live bout 3 days till i can get on it.
Use a green screed adhesive if tiling or a sealer before applying tanking,
Plenty of products out there for this purpose.

Trev

Originally Posted by aflemi

Not sure an 80 day interval in the process of laying a wet room floor is going to work for anyone...............