# Forum Home Renovation Bathrooms  What type of sand do I use for sand and mortar bed???

## Billy22Bob

Sharp birckies sand or sydney sand?

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## heavytrevy

sharp/plasterers or mortar sand will be fine.

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## Billy22Bob

Checked my levels tonight and I only need 10-15mm.
I've done wall cement render before, however not so wet mortar seems like it wont cut it at this thickness - probably too thin.
I bought some floor leveler due to it's increased strength in thin parts, but I've since discovered tonight it doesnt screeds - just does what it's supposed to do and that is level itself.
hmmmm....
I'm currently thinking - normal wet mortar with some bond crete (optional) - bondcrete the substrate before I wack on some normal render constistency mortar....let it go off like is does on the wall and then screed back - it's quite sandy at this stage.
My render is usually very tough and strong when it dries and it keys in well (without bondcrete) and has stuck for years. 
comments?

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## heavytrevy

min screed thickness is 25 mm maybee getaway with 15mm adding bondcrete.
ardex make a quickset mortar that can be feathered

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## Billy22Bob

I've got 7m2 to do 
a) paint it on the floor prior to screed (probably good to run a prime coat - ie: water down version) and 
b) add to screed in what proportion....per 20kg of sand....200ml?

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## Billy22Bob

Lanko 173 Floor leveling Compound at $30/bag and I'm estimating I need about 5 bags.
Although you can bulk it up in places with screenings 
Done my daubes and levels and will finish today ready for water proofing. 
b22b

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## Billy22Bob

attached

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## Scottythetiler

if you go to a landscape yard they can supply you with bedding sand, but you will need a ute to transport it or pay delivery.  its a medium sized sand, not too fine or too coarse. 
waterproofing is done before the bedding, which some customers try to argue the reason why.   
i use a wheel barrow to mix small batches at a time or if a large batch is needed i mix on a concrete area with a shovel.  the mixture i use is 2.5 buckets of sand to 1 bucket of cement.  then i mix it till it goes 1 colour and then apply water slowly with a spray nozzle, not a straight jet.  the technique for bedding is something that only comes from experience, its hard to read and learn but i'll do my best. 
i also use wire mesh on the floor when i am bedding to reinforce it.  there are expensive meshes that are not chicken wire but if the waterproofing is good and you're careful then you wont damage the membrane.   you need to make sure when mixing that the moisture is completely even through the blend and there are no dry spots.  you will need to keep adding a little water at a time not to make it too wet.  you dont want sloppy mud. 
when the texture is right, you will have the ability to form a tennis ball size bundle and it should not crumble and it should hold a firm shape.  if you cant make a ball shape then its too sloppy.   
when getting the level right in the room i use a laser to mark the wall all around and then measure down from the point till you reach 25mm off the ground.  sometimes you may need to go to 30/35mm depending on size of the room and falls needed.  you will want to put the bedding down in a few spots around the perimeter of the room as height guides.  having a few different length spirit levels helps a lot here.  fill out the edges at the appropriate height about 100-150mm wide in a nice firm bed.  keeping everything compacted and firm is the key to a good bed. 
you will need to make sure that the floor wastes have fall to them.  this is the tricky part and it will vary from room shape and size to waste location.  about 5mm fall over a 1000mm radius is fine.  once the edges are done to the desired height you can fill in the middle parts slowly working a section at a time, making sure its compacted and you put a level in all directions to keep an eye on whats happening.  rest the level from edge to edge (of your perimeter) and check to see how you're going for height and density. 
you will get sore knees, ankles, back and wish you hired some other sucker to do it for you.  i tend to stay on the ground and have my other minions mix and bring me constant bedding blend. 
i think there are some youtube videos of it but everybody has a different style.  the 3 people i learnt from were all different and i just combined what i thought was best from all them. 
hope this guide helps.

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## heavytrevy

Falls for general wet areas are 1/100 so 10mm over 1 meter, measure from the furtherest point to  the waste to work out the required fall. 
If doing a shower recess the fall needs to be 1/60. 
There are many arguments on whether the WP should be under or on top of the screed.
Many factors need to be taken into consideration, including floor substrate /puddle flanges etcs 
I like to WP on top of my screed , ive dug up way to many screeds that are water logged mouldy and stinking lmao 
Regards

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## Billy22Bob

Screed finished
Primed floor last night.
Still gotta do the shower hob/area prior to final taping. 
The substrate was a mess and high point sof only 5mm in some places negated the use of mortar apart from the shower. 
Membrane on top should assist in reducing smells and can flow straight down the waste (if ever it needs to) 
b22b

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## Scottythetiler

looks like a neat job mate 
how long after you did the bedding till you primed it? 
also it does not look like a thick bed, i'm going to ask the dumb question now sorry:  did you test to see if the outside of the room is high enough for that floor waste?  that floor waste looks like a botany brand (whatever the one with the boat on the cardboard box is) and they are quite thick themselves.  have you put it in place and used a level from the outside to test the fall?  you'd hate to start tiling then find out that its the highest point in the room.

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## Oldsaltoz

OK it's true I'm an old fart that has been in and around the building trade most of my life. 
A couple of things I have picked up along the way include an old bloke telling me that whenever you put a concrete screed over a concrete floor like that used for tiling the base of a shower. Your mix should be on the dry side and you should a small container of cement (no sand) slurry and apply this to the floor just moments before you drop in the leveling medium, in fact he said 'as you apply the medium'. 
For years I thought this just an old man's ravings till I came across a shower renovation that needed the old screed removed; you know what comes next, I had no end of trouble getting this off. 
Another pick up:
I can almost walk into a bathroom and tell you if the waterproofing was dine before or after the tile screed was added, it takes a few years but it does smell if the waterproofing is under the screed. I have seen old creed black with mould right through the full thickness. 
The cause is poor drainage as water will pass theough the grout and some tile types but can not drain because the pipe on the bottom of the waste is a tight fit. The cure if the waterproofing is applied before the tile base is to make sure the membrane extends down into the wast and that the tube flange on the waste has some slots cut in it (I put 3 cuts = 6 slots). Using this method avoids the above problems. 
Hope this helps. 
Good luck.  :Smilie:

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## Scottythetiler

I understand your theory oldsalt and i respect your time in the industry.  I have only been in the game for 6 years which probably is not a 1/3 of what you've done.  The method with the waterproofing under the screed is done in every new building  and as far as i have seen, all the reno's i have been involved with.  since my views are rather new compared to yours, i can only think that maybe there has been a new rule from the BSA to do such method.  i know waterproofing methods have been thoroughly looked at and changed over the last 50 years or so.  its not to say its wrong, but maybe new rules have come in about it?  i still laugh when i pull out an old bathroom to see almost no waterproofing apart from the odd lead sheet here or there and somehow they never had leaking issues over 60 years!  like i said, different methods, not wrong methods. 
i have even seen a shower wall that was basically a screed but vertical!  is was a pain to remove.

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## Vernonv

The waterproofing stuff I used (Ardex) was specified by the manufacturer to be installed over the screed, not under it. Personally I would stick with the manufacturers recommendations as they are the ones who will ultimately warrant the product.

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## Billy22Bob

Sorry I havent gotten back earlier. 
1. I established my "intile" central waste level as low as I could. Even gouged out some concrete to get it in. I then lasered out and found I could hit a 20mm grade from the doorway level (stopping angle) which is determined by my carpet level in the adjoing hallway (18mm). Thats 2m away so satisfies the 1:100-1:80 for non-shower areas as per standard.
2. The cement substrate floor was graded to the original waste which I reused and my layout is pretty much identical. As such, my beeding depth ranged between 20-3mm and as a result, (as above) I couldnt use sand and cement. I went with Lanko 173 floor leveler - great stuff but exy$. I have now used 7 bags at $30/bag (bunnings) but it goes off quick and says on the bag you can tile over it "in 4hours"....! Well, I havent dont that, but it goes off within 1 and sets within 2. It's also very scultpurable (if thats a word) and you can shape it after an hour.
3. So all the all final tile heights at the perimeters are done to +20mm from the top tip of the waste no matter how far they go - some 1500mm some 2000mm - all meet the standard. This will allow my wall tiles to be pretty much level.
4. Due to the 4hour - you can tile on it - Lanko claim  - I water proofed (primed) with Gripset 38 after about 14hrs. Thats the photo above. I then took to getting the shower hob set out and that's been the baine of my exsitence for the past 24hrs. Not so muhch the levels, but these new shower trays....tredny...but so much more surace/perimeter to get right efore membrane. Its finally ready for membrane prime tommorow morning. I did start to use sand and cement in the shower hob because of the volume/grade/lift and hence the cost - but the wait to set time really got to me so I went and bought a couple more bags of Lanko 173. So 7x$30=$210!!!! But that's bathrooms for you.

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## Billy22Bob

Though I''d post some pics of todays effort. Apart from mowing etc... 
I used geotex fabric for the shower base and you can see how I plan to drain any residue that gets under the tile adhesive down the waste.

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## Scottythetiler

lookin good mate.  how long is the extension on the base of the shower waste?  i have seen some brands of those trays that are only about 10mm sticking down.  if so, extend it with some piping of any kind and silicone/sikaflex.  its best to have 40mm or more to stop capillary action.

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## Billy22Bob

You are correct - 6mm snout.
I have it designed so that the tray will be "glued" somehow to the membrane base and that "snout" in the tray slips directly into the "slotted" inner 40mm tube by the 6mm. The Outer 65mm tube is to capture seapage (if any) from the membrane and direct it via the slots into the 40mm tube waste.
This was one of those multi size adapter thingies which I cut up to suit. 
I was going to sika the two rings to the base of the tray - as for the rest of the base of the tray surface ....more mebrane liquid? That seems to stick to anything and stay very sticked.

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## Scottythetiler

sikaflex sticks like @@@@ to a blanket so use that.  the waterproofing can work but its not meant to be an adhesive and so if used thickly, it may not set as well.  dont use tile glue as it will hold but not for years and years. 
hopefully the system you have devised will be enough for the water mate.  in theory its fine but i have seen water do all kinds of crazy things!

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