# Forum Home Renovation Bathrooms  How to remove tough screed under tiles - what methods/tools?

## DaleBlack

I have a laundry that needs to come back down to the concrete pad level to match the wood floor in the hallway next door. 
It has blue tiles put in in the late 70s and then another set in the 90s straight on top   
The first layer of  tiles come up relatively easy with a simple ozito SDS drill with a 75mm chisel bit leant on a angle. 
The issue is the screed over 20 years old underneath     
Its rock hard and only really comes up from using the pointy bit going straight down. 
One person had said that the screed shouldnt be this hard, the original tradie made it too strong but the hire shop says all screed goes this hard after 20 years? 
A local hire shop advised to use    
one of these for the tiles, not that the tiles are that much of an issue, though the blue ones sort of are. 
and a concrete grinder for the screed    
Or i could cut long strips downwards and across with a angle grider down to the pad and then proceed with the manual chisel drill. 
Any ideas or suggestions?

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## SilentButDeadly

You'd be there a while with the concrete grinder...maybe that's why they recommended it! 
I'd be inclined to try wet sawing it down to the pad in strips (same as what you suggested with an angle grinder) and demo hammering it out from there. 
Truth be told...this ain't a job I've had to try as yet so my thoughts may not be valid.

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## doovalacky

One of the  jackhammers will be a lot more effective than a SDS drill.  It's what I used in my reno. 
I was lucky and purchased  a fullboar on special up from bunnings for less than the hire cost of a couple days. 
If you have a grinder with a brick blade do a few cuts in opposite direction to what your trying to hammer.  It gives the screed somewhere to break as you hammer it.
I found once I got down to slab level and could get the jackhammer on an angle it then started lifting without doing the cuts.

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## rebuildr86

Remove all tiles first. Tiles on top will hold it together and make it stronger and more rigid. I do this day in day out. Get the tiles off and it should be much easier, unless some idiot used too much cement in thw screed, in which case it would get stronger over the years.

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## DaleBlack

> Remove all tiles first. Tiles on top will hold it together and make it stronger and more rigid. I do this day in day out. Get the tiles off and it should be much easier, unless some idiot used too much cement in thw screed, in which case it would get stronger over the years.

  rebuildr86, i believe there is too much cement in the screed and it has got very strong over the years. So can i ask what tool and what bits you use? 
 doovalacky 
Which model did you get? https://www.bunnings.com.au/full-boa...ammer_p6290253  https://www.bunnings.com.au/full-boa...ammer_p6290254

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## DaleBlack

rebuildr86, it must be hard for you (given you do this commercially) to quote in relation to screed removal, do you  
1
just assume its hard as rock and quote higher, potentially making you uncompetitive
but if you do get the job and it comes up easily, you r ahead 
or 
2 
  quote for easily removed screed with a time limit, say "12 hours allocated to tile removal"  and then if you do run into hard as rock screed then fair enough you effectively put in a VO to the client.
This is probably better for them as well, rather then just receiving a higher quote that assumes its rock hard.

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## DaleBlack

> You'd be there a while with the concrete grinder...maybe that's why they recommended it! 
> I'd be inclined to try wet sawing it down to the pad in strips (same as what you suggested with an angle grinder) and demo hammering it out from there. 
> Truth be told...this ain't a job I've had to try as yet so my thoughts may not be valid.

  The wet saw sorry, is what i meant, not a angle grinder

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## rebuildr86

I charge per hour dale, but put a cap on the total price :Smilie: 
Simple and fair.
And if someone dissagrees with this, then theyre not happy unless theyre screwing someone, so i wont work for them.
Some call this, "hiding behind an hourly rate"

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## phild01

> Which model did you get? https://www.bunnings.com.au/full-boa...ammer_p6290253  https://www.bunnings.com.au/full-boa...ammer_p6290254

  Look on ebay and for less than $200 you'll get quality on par with that less powerful Bunnings offering.
I have one identical to this and it has been great: https://www.ebay.com.au/itm/2200W-El...frcectupt=true

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## DaleBlack

*200W Electric Commercial Jackhammer Demolition Jack Hammer Concrete + 3 Chisels*I see it has 45J, I think the Ozito 1500w I have is only 25j odd.

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## phild01

The price has just gone from $197 to $203 since I last looked, must have improved it's popularity. 
It isn't light so be sure what you get is manageable for what you are doing, the less powerful ones should be okay with screed.

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## doovalacky

> Which model did you get?

  It was the 1500W job but I paid just a smidge over $200 at the time. Hire cost was close to $100 so decision was easy for me. 
It had plenty of use taking up that floor then breaking up rock as I built a fence and retaining wall at new place.

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## autogenous

5kg jackhammer. Slice with a grinder 3 inches apart of it is really hard

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## DaleBlack

> 5kg jackhammer. Slice with a grinder 3 inches apart of it is really hard

  Hi what model jackhammer do you use?

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## DaleBlack

I was able to borrow 2 other rotary hammers being  Ramset DynaDrill   565  https://www.kencor.com.au/media/pdfs/product/brand/Ramset/Power_Tools%20DynaDrill%20565.pdf 
Impact Power 10J  Hilti TE 56 https://www.manualslib.com/manual/94...page=17#manual
page 17 says 7Joules  https://ozito.com.au/products/1500w-rotary-hammer-drill/
is only 5 Joules not 25 i mentioned above. 
But iam not sure i am reading this right, how can the ebay product Phil01 linked by 45joules, so much more then the Hilti or Ramset, or am i getting confused with the rotary hammer vs jackhammer 
Also i am surprised the Hilti TE56 has less impact power at 7 joules vs the Ramsets 10?

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## Marc

You are comparing a 1100w 5 kg drill with a 16 kg 2400w jackhammer. 
Just to illustrate the difference, my bigger jackhammer, the Bosh Brute, weights 30 kg and has a 2000 W motor and 62J impact.
It's all in the weight. 
Phil's jackhammer is a knock off from Hitachi or Makita and they have been around for 20 years. I bought a knock off version by "Millers Falls" and used it extensively for well over 15 years with very little problems. Changed the brushes a few times and the pin that locks the tool in place, but the thing keeps on banging. If memory serves me right I paid $99  :Smilie:  
Try to get to the concrete slab in an area that allows for the jackhammer to be held flat and then work your way under the screed. Hearing and eye protection a must

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## pharmaboy2

> The price has just gone from $197 to $203 since I last looked, must have improved it's popularity. 
> It isn't light so be sure what you get is manageable for what you are doing, the less powerful ones should be okay with screed.

  The Bunnings one is a rip off -  I grabbed an almost identical unit from super cheap auto for $199.  We jackhammered a pool into rock with it next to a Hilti for 7 solid days.  Worked as well as the hilti, though  more likely to overheat. 
if you are removing over CFC, even a small hammer will end up going into the sheet unles you are Uber careful

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## DaleBlack

> You are comparing a 1100w 5 kg drill with a 16 kg 2400w jackhammer. 
> Just to illustrate the difference, my bigger jackhammer, the Bosh Brute, weights 30 kg and has a 2000 W motor and 62J impact.
> It's all in the weight. 
> Phil's jackhammer is a knock off from Hitachi or Makita and they have been around for 20 years. I bought a knock off version by "Millers Falls" and used it extensively for well over 15 years with very little problems. Changed the brushes a few times and the pin that locks the tool in place, but the thing keeps on banging. If memory serves me right I paid $99  
> Try to get to the concrete slab in an area that allows for the jackhammer to be held flat and then work your way under the screed. Hearing and eye protection a must

  
Ok I understand now - so that $200 knockoff is still going to be a better option for this tough screed than the Hilti TE 56 I have on loan, given that this Hilti is still just a rotary hammer itself. 
What about spending 100 more for a  *Baumr-AG 2400W*https://www.gumtree.com.au/s-ad/sydney-city/power-tools/baumr-ag-2400w-demolition-jack-hammer-commercial-grade-jackhammer/1184545876? 
It seems to come with a better set of tools by default, or at least that nice wide chisel. Does that ebay one have a fitting that accepts standard shanks? what are the shanks for these jackhammers, not SDS like rotary hammers?

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## phild01

Dale, I doubt your job needs a big hammer unless you have other uses.  I'd be worried not only will you remove screed but you'll end up going through the floor.   If it is tough to remove maybe you'll need to re-pour a new slab  :Hmmm:

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## OneZero

I bought the $299 Bunnings one and it does a great job at removing 30 year old screed along with 30 year old concrete slab. I found it to be more about technique than brute force with it. It's all in the angles, my wife agreed.

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## DaleBlack

Hi 
so as mentioned we tried a Ozito 1500W, SDS Plus rotary hammer on this screed which was useless. Impact power 5 J. 
I then borrowed these two items,    
being more professional SDS Max Rotary hammer drills. 
Though the Hilti TE 56 seemed to be broken on the chisel mode, leaving the Ramset DynaDrill   565 , impact power 10J but it also hardly made a dent. 
I was able to borrow this 30mm Hex shank Jack hammer, Hitachi H65SB2 , impact at 42J, not quite the 62j of the Bosche Brute
along with a asphalt scraper bit (not a chisel) and a standard bull point bit.     
you can see below i dug out a channel along the single leaf brick wall with the asphalt cutter bit, so as when i came back through i wasnt hammering straight into the wall.    
This unit made light work of the screed. Though, as with everything i realised the technique helps speed things up as well. Swapping to the bull point bit below   
and bringing it down maybe 150mm back from the edge of the remaining screed slab, caused segments to break away from  the rest of the screed and pad below. It worked better for the most part  then having the asphalt cutting bit on a angle trying to undercut it. Though these bits that broke away did not always do so cleanly so at the end the asphalt cutter bit was used to knock off small sections back to the slab level. 
Maybe some others have advice on that?     
Either way it was a success and done in about 2 hours including filling the wheelbarrow and wheeling it out to the front skip bin   

> I'd be worried not only will you remove screed but you'll end up going  through the floor.   If it is tough to remove maybe you'll need to  re-pour a new slab

  this didnt seem to be an issue Phild01 
Here is another closeup of the screed

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## Marc

Yes, well done. It's all in the technique, providing the tool is up to it.
I've seen removing a 40 years old screed with a bosh brute hammering at 90 degree. The whole house shook yet the screed came off the concrete slab with no issues.

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