Browse Forums Bathrooms and Laundry 1 Apr 25, 2015 4:28 pm Hello, this is my first post on the forum. A friend recommended it to me when I purchased our new house and I started asking him questions about retiling the bathroom. The house is a Grollo (F) design which was built after Cyclone Tracey in Darwin as a cyclone proof house. They are a unique design white some unique features such as almost the whole structure is concrete including the roof, floors and most of the walls with 3 levels to the house. The bathroom is literally one whole room which one half of the room is an open shower and bath next to each other and then the other half is vanity and toilet with two walls that only goes three quarters of the way to the roof. The bathroom on the first level is built over the storeroom on the first level. When we bought the house the tenants who were in it said that there was a small leak in the store room underneath the bathroom and the landlord put silicone around the for bottom edges of the shower and the leak stopped. As the tiles are still original Commonwealth brown tiles of the day I thought it would be a good idea to retire but now after purchasing the tiles I am confusing myself about the best way to go ahead and start the job. I purchased 300x600 charcoal gloss porcelain wall tiles and 300x300 charcoal Matt floor tiles. It was suggested to me to use a liquid leveller on the floor and lift up the drain pipe in the floor because the fall is very exaggerated around the drain and would make tiling with the 300x300 tiles harder. Then waterproof over the liquid leveller and old tiles before retiling over that. I then thought as all the walls and floors were concrete I would rip up the old tiles start from scratch but now that we have moved into the house I realised that some of the walls are cement sheeting in the shower and I didn't want to take the risk of having to put new sheeting up if I remove the old tiles and damage the sheets. On the other hand as I am using larger wall tiles there would be places that I need to tile that don't have tiles. So any advise or previous experience would be greatly appreciated. Thanks Not sure how to attach photos but I have plenty Re: Tiling over existing tiles or not? 2Apr 25, 2015 7:08 pm The best solution is to remove the old tiles and then install a new water proof membrane in accordance with present day regulations. The existing wet areas (if built immediately post Tracy) probably do not have a waterproof membrane installed. The floor would also probably need to be re-screeded to ensure correct falls. Re: Tiling over existing tiles or not? 3Apr 25, 2015 7:36 pm Thanks Beetaloo, That was my initial decision to do the job right. I didn't know that they didn't use waterproofing back in the day. Would there be an option to try and just remove the floor tiles and bottom row of wall tiles? I'm just concerned about damaging the sheeting and then having to replace or is the cement sheeting tough enough to do the job? Also what form of tradesperson would you aproach to re screwy the floor? Re: Tiling over existing tiles or not? 5Apr 25, 2015 8:47 pm That's why I was toying with the idea of using this liquid leveller to level the floor better and then getting a slight fall by just pushing the tiles down a bit more to get a bit of fall? Anyone can tell me how to post a photo of the bathroom? Re: Tiling over existing tiles or not? 8Apr 26, 2015 11:32 am Never tile over existing tiles as it allows water to flow between the 2 layers. As stated above there is probably no membrane in the bath area maybe just a basic resin compound in the shower area. I wouldn't waste money on using a leveling compound to get floors level as you need to screed the floor anyway, you cant just pack tiles up and down to give the fall. The water will penetrate the grout and go under the tiles and the screed will divert the water to the drains that's why its best to screed to include the falls in the floor surface and not just level. Also if you try and pack the tiles to create fall you end up with dolops of glue on the tile and it creates hollows under the tile leaving the tile not evenly supported than becoming susceptible to cracking. Re: Tiling over existing tiles or not? 9Apr 26, 2015 2:11 pm Thanks guys. I'm seeing a pretty consistent theme here. Rip it all off and start from scratch. I might check if the waterproofing company would screed the floor? Last time I helped someone do some tiling we used a cup stone on a grinder to level all the floor and get rid of the old tile mud. I have heard is something called a gimbler. Any preferred method to prep the surface? Re: Tiling over existing tiles or not? 10Apr 28, 2015 9:45 am If it is a concrete floor then a small jackhammer with a spade and/or chisel bit is your best bet to remove both the tiles and any screed if that's how they laid it originally. Just get as much of the floor back to the original slab as possible and as smooth as you can too. It makes working in the room for both the waterproofer and the tiler a lot easier. As for the walls - as others have said, just bite the bullet and replace the sheets. You can run new wiring or at least have power points and lights exactly where you want them and maybe re-position your plumbing to suit as well. Stewie Re: Tiling over existing tiles or not? 11May 01, 2015 4:27 pm It would be good to rip up the entire bathroom although it’s a time consuming process. It will give you the chance to find out where the water leak was coming from and put a fresh new waterproof membrane. After putting pH neutral silicone along the corners and priming the surface, apply minimum 2 layers of waterproof. Make sure to apply the proofer into the drain to create a funnel like effect with the membrane. We recommend Davco K10 plus. Re: Tiling over existing tiles or not? 13May 17, 2015 12:59 pm Definitely rip up the tiles and jack hammer the sloped shower base as all of the tiles will eventually lift in big sheets like our Grollo did. There is a pathetic attempt at waterproofing in some grollos but not effective (only on parts of the floor, not on the walls even in the shower area). The walls are solid concrete, with the exception of the wall behind the shower and the alcove where the basin is. The cement sheeting looks to be reasonable at 10mm or so thick but there are large gaps between the sheets around 10mm which are not even sealed even in the shower!!!! Water leaks through the gaps in the cement sheets and also leaks into the wall at the base of the shower. this water usually leaks into the store room below and also in under the wardrobe in the room behind the bathroom. The wall tiles are laid with minimal gap which was to code back in the day but the standard i believe has changed to min 3mm gap to stop the tiles from lifting off the walls when it gets hot and the there is expansion which is common in grollo bathrooms also. Our shower pipe leaked so we currently have a big hole cut in the shower wall to fix it so will be renovating the entire bathroom in the next few weeks. I would definitely rip out all of the tiles and chip out all of the sloped concrete in the shower base back to the slab and start again. If you don't have the tools I would highly recommend the Ozito hammer drill from bunnings http://www.bunnings.com.au/ozito-850w-r ... t_p6290249 and some sds drills and chisel bits to get you started http://www.bunnings.com.au/frost-17-pie ... t_p6360017 Preparation is key. Remove all tiles with hammer drill and chisel bit (+ shower base and hob if you want a nicer flatter finish) Grind off any large lumps of tile glue with diamond grinding cup disc remove debris and dust. Use a neutral cure silicone Like Selly's wet are speed seal - purple label around all of the corners and all of the cracks where the wall meets the floor. prime all surfaces to be waterproofed with Uniprime - brush it in good with an old 3" paintbrush or broom. then add 2 coats of water proofing membrane with the second coat brushed on perpendicular to the first coat(90 degrees) to make sure all gaps are sealed. All cement sheet joints and wall corners should have 1 coat or waterproofing membrane applied then waterproofing mesh applied to all joints while still wet then coat the mesh again to finish off the first coat. I would steer well clear of the bunnings waterproofing membrane and go with either the blue Dryflex PUMP 15 Liter drum from Northern Tile Gallery or the orange W1 Aqua Block from City ceramics. Both have been tested and approved by the CSIRO and are quality products, you get better coverage with Dryflex and it is a little easier to work with. Alot of the better renovated grollo bathrooms remove the toilet door and cut the wall down behind the toilet to just above the cistern level to really open the room up. http://www.realestate.com.au/property-h ... -118530747 If you change any in wall plumbing you will need a plumbers certificate and probably a permit and you should ask your tiler for a waterproofing certificate to australian standard ASXXXXX. Most tilers will let you do the waterproofing work yourself if you follow the right process and take photo's as you go. There is a building advisory service you can ring up if you need advice just search on the internet for the number. There is a handy facts sheet on waterproofing requirements in the NT that can be downloaded which states the minimum, however i would just waterproof the floor and up to 2m high on every wall in the entire bathroom (shower, basin, bath not toilet area) as you should have enough and it doesn't take much longer for piece of mind. Re: Tiling over existing tiles or not? 14May 18, 2015 8:20 pm Mate that was a massive amount of great information and I can't thank you enough. You obviously know quite a bit about the grollo so any info is good info. Given me more courage to get stuck into it. Just wanted to address a couple of your points. Water leaks - definitely be worth ripping off the cement sheeting and checking the plumbing whilst I am there. I didn't click onto the fact that it can leak into the cupboard behind that wall. It is a pretty new inbuilt cupboard and I cant check the floor or wall so going from the shower side will be best. Jackhammering the floor - If I understand you correctly you are saying that the floor has already been raised and instead of getting it screed with new concrete just chip away the old concrete to get to the slab. I looked today and the shower floor definitely looks higher that the bathroom floor by the vanity. Waterproofing - thanks for the advice on the waterproofing. very much appreciated. I am getting some other stuff done on the house so I will add the waterproofing to the building permit and get it done regardless. A certifier told me that if I didn't change the original plumbing then I don't need a certificate but I am thinking that if I rip that cement sheeting wall off the shower I might just change to two shower heads anyway and be done with it. Tiling - I am doing the tiling myself so will need to do the whole job and get the certifier to approve the waterproofing. Tools - Thanks for the links Toilet Wall - that's unreal how much it opens up the bathroom. I am pretty keen to give that a go now too. All the best and thanks once again. Hi, I'm clearing the tiles from our horrid 50 year old bathroom and preparing to lay new ones. Bugger of a job getting the old… 0 8087 just pull up the slate. If you go over the top, your tiles would not have an even surface to be glued to. Im no tiler, but i can imagine a couple of things being an issue… 1 259 Levelling compound Ardit is the best but buy a bag of sand and make sand dam to protect your wood floor 2 15252 |