Ceramic tiles: floor preparation

[Groggy]

I have removed the tiles from my entryway and will soon need to have new tiles laid. There is still a layer of the old adhesive on the floor and I am wondering just how clean and flat the floor has to be? At the moment there is about 3-5mm of old adhesive in places.

[Honorary Bloke]

Groggy, the tile likes the floor to be FLAT. Get the old stuff off if you can.

[Groggy]

Ok, I was hoping it wouldn't be necessary. Thanks Bloke!

[Honorary Bloke]

Groggy,

Sorry for such a short reply, I was in a hurry and left it for others to fill in.

Over here you can hire a machine by the half-day to scrape the floor clean--a possibility. Also, if needing an excuse for a Fein Multimaster this is it, use the scraping attachment.

The problem is that tiles, as hard as they are. crack quite easily on an uneven surface. If your tiles were laid on a cement board underlayment, just tear out the old board and put new. If not, scrape away.

I also commend you to this site for in-depth information if you need it. It is the U-Beaut of tiling forums:

http://johnbridge.com/vbulletin/index.php

Good luck.

[Cliff Rogers]

I used the good old Ozito Rotary Hammer with a wide spade bit & the rotary function turned off, tip it over at 45°, pull the trigger & follow it across the floor.

[Pulse]

Hey groggy, A couple of methods I've used (as well as cliffs)

1. fill with self-levelling compound
2. use a diamond cup grinder wheel (gasweld was getting some in cheap) - very messy though

Cheers
Pulse

[Groggy]

Over here you can hire a machine by the half-day to scrape the floor clean--a possibility. Also, if needing an excuse for a Fein Multimaster this is it, use the scraping attachment.
......snipped...
I also commend you to this site for in-depth information if you need it. It is the U-Beaut of tiling forums:

http://johnbridge.com/vbulletin/index.php

Too small an area to hire something. Thanks for the link!

I used the good old Ozito Rotary Hammer with a wide spade bit & the rotary function turned off, tip it over at 45°, pull the trigger & follow it across the floor.

How wide is the spade bit Cliff? Biggest I have seen is about 35mm.

Hey groggy, A couple of methods I've used (as well as cliffs)

1. fill with self-levelling compound
2. use a diamond cup grinder wheel (gasweld was getting some in cheap) - very messy though

Cheers
Pulse

diamond grinder hmmmm...

[Cliff Rogers]

How wide is the spade bit Cliff? Biggest I have seen is about 35mm.

40mm, it comes in the $25 Medalist set from Bunnies. The set has the same tools that came with the drill but it also has heaps more including some nice long masonry bits in usefull sizes.

diamond grinder hmmmm...

Lots of fine dust unless you make a 'mudwall' dam around the area & do it wet.

[Pulse]

Lots of fine dust

You can say that again... I had to stop every now and then when i couldn't see the grinder in my hands. I think gasweld was selling one for $35. They had a problem with the import so I had to pay $180 for a Dimas one. Good quality though...

Cheers
pulse

[rod1949]

Hire an air operated Needle Scabler. Works a treat.