bathroom holes

[Greyham]

:confused: Seeking some advice re a bathroom renovation, my house is on a slab and it appears that in the bathroom, they put the bath and bathroom vanity in, and then they have poured another slab, about 25mm thick, so on removing the bathtub and surrounds (due to water damage) I am left with a rather large hole.

When I eventually remove the vanity, there will be another hole......

I will be replacing all the floor tiles, as there are the ugly 'Mission brown' 25mm square tiles.

I can remove the second slab, as I removed something similar in another part of the house, and it comes up very easy, or?????.

So, I am asking what you would do, ie , remove all of the second slab or remove the tiles and fill in the holes.

what to do what to do, oh yeah see the bank

six of one, half dozen of the other I suppose, but if someone has had this problem, I would love to hear what you did

[Skew ChiDAMN!!]

Can't speak from experience here, but a couple of things pop to mind.

What sort of floor do you want to put down? What height is the current floor in relation to the entrance/exit floor(s)?

When you're removing the tiles, you may find the choice already made for you. If the 2nd slab starts lifting, is friable or cracked then IMHO you're better off lifting it to avoid future problems. Besides, although removing it would mean more work it'd probably give you a wider choice of materials. Ever thought about laying slate or sandstone pavers? :D



PS. I'm not joking about the pavers... they look good but it depends on your taste and the rest of your decor, of course.

[johnc]

If you want to do a decent job pull up the second slab, it is not uncommon to have slabs poured this way. The original slab should be lower than the slab in the rest of the house, and the second slab is put in as a leveller and sub base for the tiles. It enables you to get the fall and angles you want to floor drainage or whatever style of bathroom suits. Can't remember the mix but it is not that strong, I'm sure someone else reading your post will give you better detail than this.

John

[Shaty40]

The "second slab" is just a screed to ensure the levels are correct for tiling, if the job was done right , you would be lucky to get the tiles up without taking the screed with it. just rip the lot out and start a fresh.


Tim

[Auspiciousdna]

Yes this (slab) is called a dry screed bed, consisting of a damp sand and cement mixed to from a semi-dry bed, after which dry cement would be sprinkled over the screed and the tiles laid onto and tapped down, the moisture in the screed would set off the cement bonding tile, bed and cement together. Mostly used by Europeans to lay tiles, the poms wouldn’t use this method, but rather laying a normal concrete slab with the levels and slopes for drainage and then after drying using a compound or cement slurry to adhere the tiles to the slab. The dry screed method is a much more physical (its murder mixing the screed to a correct blend) but generally a better method. If you can leave much of the screed down you might be able to use the pom’s method to relay the tiles, but I doubt it.

[Greyham]

Thanks guys, I figured as much, having to remove the secod slab seemed the easiest way.

A question comes to mind, is it a relatively easy job to replace the second slab or is it a job best left to the professionals. In saying this I consider myself to be slightly handy and can do most jobs, is there a easy method to do this?

Thanking you in anticipation.

[Gaza]

Not hard to do, the floor tiler will normaly do as part of there work.

IF DIYing make sure you prime the surface with bondcrete and then get the heights right, and grade it to the floor waste.

[Arron]

This is assuming your floor slopes to a floor waste, and perhaps a shower waste as well.

Just finished laying a tile base (screed bed) myself. Only the second one I have ever done - and I did not find it easy - getting the mix dead right and getting the levels right so that the water flows neatly out the floor waste, while being confident that it will last through many years of hard wear - all not easy. I had to get a friend (tiler) to come and help me with some of it at short notice, and had to pull some of it up and redo it - because if you cant be 100percent confident that its done right then you dont want to be putting tiles on it. If you havent done it before its one job I would call a tiler for.

It used to be easier when the fashion was for smaller tiles because you could put more slope in the floor - but with most floor tiles these days being 300mm square or bigger then you are very limited in the slopes you can do so they must be dead right.

Incidently, on your question of whether to pull up the existing tile base or not - the answer is if you want a quality job then definitely pull it up. The quality of a tiling job reflects the quality of the preparation work done to the surfaces beneath it. As much as you can, you want big, flat, sound surfaces - not bits and pieces. Tile bases usually come up pretty easy - I bought one of those $60 rotary hammers from Bunnings which does it easy.

To add to Auspic.DNA's comments, you can also lay the tile bed, let it mature and then fix the tiles with a flexible tile adhesive. Our Tiler friend recommends this method if you are patching a floor - such as you will be if you dont remove the tile base - because if cracks develop between the old and new bits then the tiles will not be affected.

Also, dont forget, budget heaps of time and effort for waterproofing. Before or after the tile base is laid - your choice - I prefer to do it after the tile base is down and will elaborate if interested.

Arron

[Greyham]

Arron, Thanks for your advice, it has made it easier for me to decide which way to go, ie, rip up the whole lot and start again.

My house is a steel framed house, with asbestos walls, the current shower is not very well sealed and has leaked in between the slab and walls, which in turn has attracted roots from somewhere.

I envisage that I will rip up the slab, re do another one, then seal around the base of the wall then tile, hoping to seal it completely from further leaking.....does this sound feasible.

The bathroom has a seperate little room for the toilet, I intend tiling in the toilet as well same tiles.

will be interesting to live in the house whilst redoing the bathroom..

Again, thanks for your help

[Auspiciousdna]

To add to Auspic.DNA's comments, you can also lay the tile bed, let it mature and then fix the tiles with a flexible tile adhesive. Our Tiler friend recommends this method if you are patching a floor - such as you will be if you dont remove the tile base - because if cracks develop between the old and new bits then the tiles will not be affected.

Arron

Thanks for the heads up on the patching

[Arron]

First - please remember I am not a professional and this advice is based on my experience with doing a few bathroom rennos and a lot of guidance from my friend a tiler of 40 years experience.



I envisage that I will rip up the slab, re do another one, then seal around the base of the wall then tile, hoping to seal it completely from further leaking.....does this sound feasible.


Not too sure what you are meaning here. I would be ripping the tile base (screed bed) up - the top 20mm of sand and cement, not the whole concrete slab. I will presume that is what you mean. You can then waterproof at that point, or you can lay the tile base and then waterproof on top of that. I think it is better to waterproof on top of the tile base - stopping the water at its source rather then having a soggy tile base in years to come. The way I have done waterproofing is as follows - but there may be other ways. To create the actual waterproof membrane use a product like LiquidFlash. Use cloth tape (sometimes called scrim) made for the purpose, to bind the walls to the floor. Its about 150mm wide, so put it so half is on the wall, half is on the floor, and soak plenty of LiquidFlash into it. This doesnt really stop the wall and floor separating as the wall flexes, but it means a tough flexible membrane spans the joint between two so the water will not get through, the usual cause of floor leaks. Then paint on two layers of LiquidFlash across the entire floor - and up the walls to about 300mm over most of the bathroom but up to about 2 metres in the shower area, and perhaps around the vanity or anywhere else where the wall might be regularly splashed. The waterproofing membrane material is expensive, but the correct way to regard tiles and grout is as porous and always leaking - which they will be after they have been there for a few years even if they dont look it. Make sure you paint up to and over the edge of the floor and shower waste pipes and inside a bit, so that water does not seep down the join between waste and tile bed. You will have a very tough, single-piece waterproof skin over the floor and walls by the time this is done. If you tile the walls first, put another coat of LiquidFlash on the floor after doing the walls to patch up any holes or damage you may have made walking on it. Then make sure you use a tile adhesive that specifically says it is suitable for putting over the type of waterproofing you used. Also, check how long the waterproofing needs to cure before you can tile over it. Once the walls and floor are tiled, grout as normal but do not put grout in the joint between the wall and floor tiles - you will be putting a bead of silicon there and it is better if it penetrates some distance down into this gap as it gives it a real key, rather then having a just a thin skin sitting on top. Anyway - put a narrow bead of silicon around all the joints between floor and wall - and up the joins of the walls in the shower.

What I have described above is a real deluxe method of waterproofing. I have noticed that most professionals take shortcuts at various places, but if you do it like I've suggested you will not have leaks for many years to come. I dont really know much about asbestos walls or steel frames, but I am assuming the need to waterproof properly is just as strong as with a timber framed house. My main concern would be with the walls flexing - particularly at the midpoint between studs such that the bottom of the wall flexes or can be pushed away from the floor, so you may need to take steps to eliminate any wall flexing.

If you need to plaster or fix any walls, use Wet Area Base Coat on the joints, over tape, it will bind the walls together across the joint, ordinary plaster does not do so very well.



The bathroom has a seperate little room for the toilet, I intend tiling in the toilet as well same tiles.

I dont like the sound of this. I would be removing the walls and making it all the one room if it were mine - just for the aesthetics.



will be interesting to live in the house whilst redoing the bathroom..

In our last case we were 6 weeks without a bathroom (we had lots of structural issues to deal with as well). My wife had showers at the gym, but I just moved the old cast iron bath outside to the back lawn and every day filled it up with buckets of water and had a bath there - wearing swimming trunks of course. It was midwinter - and after a while I started getting embarressed about it so started doing it at night.
The thing that really annoyed me was the dust in the house.

good luck
Arron