Removing cement grout from pammet/quarry tiles

[simonanna]

Hi all,

I have an exciting weekend ahead of me trying to clean cement grout from the edges of about 600 pammet tiles prior to laying them. There is also some cement screed on the back of the tiles.

I have read some advice about cleaning quarry tiles but it seems to relate mostly to removing cement stains rather than great big lumps of the stuff. Is my only option to use a paint scrapper/scutch hammer? Are there any nasty chemicals I can use that might loosen it? Can I leave the cement screed on the back of the tiles? (They are going down on a concrete floor.)

If the only option is to chip it off can anyone recommend tools/methods they have used which reduce the risk of damaging the edge of the tiles?

Thanks,

Simon

 

[Moo]

I used an old wood-chisel on mine.

Well, I say 'old'. It was certainly good for nothing else by the time I'd finished the first pamment.

 

[Pford75]

And if possible, clamp the tile before 'chiselling'...might seem like a pain....but it's surprisingly easy to slip and gouge either your hand or the face of the tile

 

[inwood]

If you think you're going to clean 600 in a weekend you might have a surprise ahead of you. I had 650 to clean. All in all it was probably two weeks work by the time I'd finished.

With regards the cement grout - yes, unfortunately there isn't any easy way to do it. As Moo says an old wood chisel is ideal.

 

[skier-hughes]

I used wood chisel, mallet and a work mate to hold them.

 

[simonanna]

Hi all,

Thanks again for the other suggestions. inwood - you weren't wrong this really is a time-consuming process. One thing I did find useful that sped it up a little was using a pressure washer to clean off the looser dirt and a chisel or one of those stanley blade scrapers to get the cement grout off.

One more question: I had left them outside for a bit too long (6 months +), and although they were covered in tarpaulin, some had some nice black mould on them. I have sprayed this off but am concerned it will reappear after I have laid them. Is there any treatment/sealant that would prevent this? Am I OK still using cement and sand for adhesion and grouting or should I use something fancy (and expensive!)?

Thanks again,

Simon

 

[Lime]

I've recently had to do much the same thing, cleaning hundreds of tiles, some with dense cement all over the undersides too.
Chisels caused more damage that a small angle grinder with a diamond stone cutting blade.
At top speed I was cleaning 60 - 80 an hour.
Washing and cleaning with a high pressure washer is a good idea both before and after cleaning.
I wouldn't dream of using cement again.
Lime based mortar does an excellent job.
Lime from the builders merchant is fine and soft and sharp sand for grout and laying the base respectively from B&Q is fine.. useful because they sell it in convenient bags.

 

[rebeccac]

I've been cleaning bricks too but it was lime mortar not cement so it takes minutes to do! Whenever we encounter cement we curse knowing the whole job will take ages.Future generations will thank you !

 

[simonanna]

How long does lime-based mortar take to dry? I know there are different types, are some quicker than others? What mix would you use for mortar and grout?

Thanks,

Simon

 

[inwood]

Simonanna, I had the same black mould appear on mine since I stacked them wet before laying. Since they were being laid on an NHL5 lime screed they needed to be wetted as they were laid (to stop the tile drawing too much moisture out of the screed), so I used my plasters bath full of water and got my helping hand to put about 30 tiles at a time in the bath for a good soaking. As each came out they got a good scrub with a scrubbing brush which removed most of the black mould. They've now been done for about a month and no mould has appeared. I think (altough I'm no expert) that the black mould only grows were there isn't any sunlight so once they're laid you should be OK.

 

[rebeccac]

I've read that you can spay hydrogen Peroxide on mould.This is reasonably cheap and easy to obtain.Possibly it should be diluted ?