Ok i was on here about a month ago saying i was going to tile over tile. Well that changed when i saw how easily the old tile came up. The sub-floor seems to be in pretty good condition but it has left some of the old thinset. I want to put down backerboard. Can i go over the old thinset or should i try sanding it off, if that will even work?
If it will what kind of thinset do you use to glue the backerboard to the floor, the flex stuff? Oh and 1 last thing do you screw or nail backer board?
Replies
You're really better off removing all of the old thinset. I have done it both ways, and leaving the old was definately a compromise. I used the backerboard screws ... they have a square drive and nibs under the head so that it will sink flush. Don't forget that the backerboard does not add any strength to the floor ... it just provides a good surface for the tile ... so if there is any question about floor deflection you need to add plywood then the backerboard.
Whenever you are asked if you can do a job, tell'em "Certainly, I can!" Then get busy and find out how to do it. T. Roosevelt
Edited 8/31/2004 8:47 am ET by Ed Hilton
The floor seems very solid. Plus i wouldnt know what to do with the toliet flange if i build up to much. Do you think a beltsander would take care of removing the old thinset? It seems to ber very thin coating.
The potty flange is the easy part. there are extension rings available, and if it's just 1/2" or so, jumbo wax rings work.
Yeah, a belt sander with very coarse paper would work. Kiss your marriage goodbye. You will find grit in every imaginable part of the house, and some places you can't think of. Consider using a sidewalk scraper, or a floor scraper. I used a wide chisel in my Bosch Bulldog and got right doiwn to the original concrete. It is very messy, but working off a smooth surface for the tile was worth the effort.
If you have the room (height) you might trowel on a somewhat thin layer of thinset and lay the Hardie board into that, and then screw it down. make the mortar thin enough so thet it gets squeezed down by the hardie ... you don't want any voids. Like peanut butter between two crackers ... when you squeeze a little, it fills all the spaces.
Whenever you are asked if you can do a job, tell'em "Certainly, I can!" Then get busy and find out how to do it. T. Roosevelt
Floor scraper and then a facing or rubbing stone... Vac..
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming.... WOW!!! What a Ride!
Crep,
I've done this on a kitchen floor after removing the tile that came undone 'cause the underlayment was not fastened well.
Scape, scrape scrape, get ALL the loose thinset off, rubbing stone on the high spots. You won't get it all, just get the loose stuff off. I then screwed the living crap outta the ply. 4-6" centers, two rows in between the joists. Screws long enough to go into the joists on the joists, in the field a 1/4 or 1/2" longer than the sum thickness of the two layers.
Vacuum, apply bonding agent. It is sorta like carpenters glue, you can get it at a masons supply yard. You can roll it and brush it on. Wait a day and skim coat with thinset.
With some skill and patience you should be able to get the floor prety flat. It's work, but if you can't add the height then it is an option.
Eric
my all time favorite scraping tool ...
works wonders on old thinset ...
the hook end of a ... Wonder Bar!
it's the most comfortable scraper I've come across ...
plus ... works well in both push and pull directions ...
and ... for the stuborn stuff ... grab it like a hammer and pound away ...
Jeff
Buck Construction, llc Pittsburgh,PA
Artistry in Carpentry
Jeff jeff jeff this is the new millenium , I use a air chisel with a wide blade... works like a charm...:>)
Darkworksite4:
El americano pasado hacia fuera ase la bandera
I'm old school ....
I can get that damn floor scraped before ya find the extension!
JeffBuck Construction, llc Pittsburgh,PA
Artistry in Carpentry
of course ...
I will not deny ...
I do have a 1" chisel bit for the bosch bulldog ....
JeffBuck Construction, llc Pittsburgh,PA
Artistry in Carpentry
Now that's a little accessory I'm gonna have to buy real soon....
Dinosaur
'Y-a-tu de la justice dans ce maudit monde?
old prybar for the big stuff. Porter Cable right angle with 60 grit. helper standing right there with shop vac running. wear glasses and a dust mask.