My 1st Job Removing old adhesive - TilersForums.com

[Shooter999]

Something like this:

Grinding cup

I can not stress enough how messy this is, tape up gap around door, wear MASK, EYE PROTECTION & GLOVES!
Go tentively at first to see how much pressure to use, you WILL tear up the ply if you're too heavy handed!

If you've never used a grinder I'd suggest you give Geoff's idea above a go first, soak the adhesive with water and use a bladed scraper, not a paint scraper.

Bladed scraper

Thanks for the prompt reply. I'll give the scraper a go first.

Cheers.

 

[Flintstone]

I would waste your time and effort scraping that off, it's chipboard so needs over boarding anyway. Check to make sure it's secure and not bouncing as those chip board floors often do. If it's ok, over board with hardi, use a suitable tile adhesive to stick it down, mix it thin ish, probably a 10mm trowel will easily sort out that then ofcourse screw it.

@3_fall any reason you can't just apply a thin layer of leveller ?

 

[Flintstone]

 

[Shooter999]

Thanks for the reply. I've tried the scraper, and it's not making much of a dent.

Was about to go and purchase the grinding cup.

When you mention a thin layer of leveller, can you expand? Do you mean apply a thin layer to the adhesive that is already there, and then tile on top of this? If so can you recommend a leveller?

The boards are fine, with no bounce in them.

 

[Flintstone]

I was referring to 3_fall when i mentioned leveller, if you look at my photos, that is what I would do with your floor, stick the hardie straight over it with tile adhesive and a decent sized notch trowel

 

[Shooter999]

Again, thanks for the reply.

Is there any benefit to boarding it compared to grinding away the current adhesive (apart from less mess, although boarding will be more expensive).

If I board it, it will reduce the clearance available between the bedroom and the bathroom.

Thanks for all replies.

 

[Flintstone]

You need to board it regardless, you should not tile onto chip board.

 

[Shooter999]

Thanks for the information. I'm slightly confused!!

If I grind all of the adhesive away, won't it be back to its original state, as it was when it was 1st tiled, where they would have tiled onto the boards? Or is this now considered bad practice?

Are you recommending that there is no point in removing the existing adhesive and I should just hardiebacker the whole floor (on top of new adhesive).

For information, the house was built in 2005.

 

[Flintstone]

Some people do tile on to chip board but it's not advisable, nobody on here will advise it I don't think.
That's what I would do, overboard with hardie over the floor as it is, no grinding. Just take any lumps or high bits off.
What tiles are you using

 

[Shooter999]

Again thanks for the reply.

Apologies for all of the questions, I'm not questioning your advice (as you're a professional and im a complete novice!), I really appreciate the fact that you're taking the time and patience to reply to me, I'm just trying to gain an understanding.

I was under the assumption (possibly mistakenly) that it was either remove the existing adhesive and then tile onto the existing floor or hardiebacker the floor as it is.

However you're saying that if I followed the advice given above about the scraper and grinder cup, I would still need to hardiebacker the floor, but your method will mean less work for me.

We'll be using porcelain tiles (although the wife hasn't picked them yet).

Is there an adhesive and trowel you can recommend for laying the hardiebacker onto?