Concrete shower base removal

[Kendorr]

I would like to remove this shower base from my new project. As you can see, it's rather rusty around it and water is still seeping out, although that does appear to have now stopped. From what I can see, the concrete was cast straight onto the baseplate.

 

I'm going to buy some stone cutting disks for the angle grinder and see if the cutting will help to free it and/or break it up.

 

Has anyone done anything like this before and can give any advice (helpful if possible please) 🙂

 

Thanks, Kevin

[BEngo]

Do not use stone cutting disks.  You will not be able to see for cement dust and will need a respirator or a hell of a lot of dust masks.

 

Try hitting it wiv a sledge hammer and cold chisel. Slow but you will get there.

 

If that fails,  hire a Kango hammer with a 1 inch chisel point  and a  bolster point and break it up with that. Go at a strip about 100 mm wide, from the sides. Use the chisel fir this. Once you are down to the base plate go at the join between the base and the shower to widen the slot. Use the bolster for this.  Dont use  a pointed point anywhere and don't go at the steel at anything approaching a right angle.

 

N

 

 

[Tony Brooks]

Another option. Drill large holes in the concrete and hammer a tapered wedge in to slit the concrete. Or an SDS drill with rotate turned off and a point or chisel bit.

 

I would not like that job.

 

I suspect that a hammer and chisel applied to the vertical concrete to cross member interface on the far side may break the whole of that section away from the steel.

[Onewheeler]

I'd try an SDS drill set to hammer, with a chisel bit. See if you can open up the interface between steel and concrete - once started it might all ping free.

[Kendorr]

9 minutes ago, BEngo said:

Do not use stone cutting disks.

Thanks, you've just saved me buying some!

 

Good advice, thanks to the three of you, drill and bolster chisel next time I go and see what progress I make.

[Tony Brooks]

28 minutes ago, Kendorr said:

Thanks, you've just saved me buying some!

 

Good advice, thanks to the three of you, drill and bolster chisel next time I go and see what progress I make.

 

Unless you chain drill, I am not sure how a bolster chisel will work.  Driving a wedge shape into the hole to stress the concrete I think is more likely to split chunks away, but take heed of BEngo, don't drive whatever you use into or through the hull.

[David Mack]

4 hours ago, Onewheeler said:

I'd try an SDS drill set to hammer, with a chisel bit. See if you can open up the interface between steel and concrete - once started it might all ping free.

I agree with the SDS hammer drill to break up the concrete. But I would be very wary about using it to open up the gap between the steel and concrete. If the concrete is sound that will just bend the steel away, and maybe break the weld between the steel plating and any framing embedded in the concrete.

If water has got under the concrete the steel plating beneath may be corroded and thin, so be very careful...

[Kendorr]

37 minutes ago, David Mack said:

If water has got under the concrete the steel plating beneath may be corroded and thin, so be very careful..

That is my concern, luckily the boat is on hard standing, but I do intend on being very careful, thanks David.

[magnetman]

Is the Boar raised enough for you to get under it and hit the area with a big hammer? Probably not but if so you might get an idea what the condition is like and whether there may be rust between the concrete and the steel. 

 

good luck with it! 

 

For disc cutting I thought the general idea was to do it wet but I have never cut concrete. 

 

 

 

[ditchcrawler]

10 minutes ago, Kendorr said:

That is my concern, luckily the boat is on hard standing, but I do intend on being very careful, thanks David.

I was about to suggest that

[magnetman]

One can hire concrete cutting chainsaws but thats probably a bit dangerous if there is steel as well. Also I guess you would need a ticket. 

 

I wonder if a jack under the Boat to buckle the plating slightly might work. 

Edited December 20, 2023 by magnetman

[Kendorr]

19 minutes ago, magnetman said:

hit the area with a big hammer? Probably not but if so you might get an idea what the condition is like and whether there may be rust between the concrete and the steel. 

Good idea, if nothing else it may break any bond between the concrete and the steel. It's sat on 2 sleepers, so only about 9 inch space, but I'll give it a go - I'm not intending going back 'till a week Thursday.

[jonathanA]

I've found a SDS hammer drill on rotation stop to be a very effective device for breaking up concrete   chiselling out brick work etc. Not necessarily very quick but a damn sight easier and quicker than a lump hammer and chisel. I'd use smallish chisel bit.  

[David Mack]

11 minutes ago, jonathanA said:

I've found a SDS hammer drill on rotation stop to be a very effective device for breaking up concrete   chiselling out brick work etc. Not necessarily very quick but a damn sight easier and quicker than a lump hammer and chisel. I'd use smallish chisel bit.  

And if you don't already have one, worth buying a cheap corded 240V model from screwfix/toolstation/aldi/lidl just for the job. They usually come with a selection of bits which will be good enough for the job.

[Kendorr]

33 minutes ago, David Mack said:

46 minutes ago, jonathanA said:

I've found a SDS hammer drill on rotation stop to be a very effective device for breaking up concrete   chiselling out brick work etc. Not necessarily very quick but a damn sight easier and quicker than a lump hammer and chisel. I'd use smallish chisel bit.  

And if you don't already have one, worth buying a cheap corded 240V model from screwfix/toolstation/aldi/lidl just for the job. They usually come with a selection of bits which will be good enough for the job.

And I've just found that a very good mate has one with a couple of chisels that will be borrowed for next Thursday. I'll let you know how I get on.

 

Thanks again for all the replies.

[ditchcrawler]

7 minutes ago, Kendorr said:

And I've just found that a very good mate has one with a couple of chisels that will be borrowed for next Thursday. I'll let you know how I get on.

 

Thanks again for all the replies.

Dont forget the goggles 

[Kendorr]

35 minutes ago, ditchcrawler said:

Dont forget the goggles 

Absolutely, as retired Technology teacher I always practise what I drummed in to my students 🙂

[Tracy D'arth]

43 minutes ago, ditchcrawler said:

Dont forget the goggles 

And ear defenders, the racket in a steel boat will be horrendous.

[truckcab79]

48 minutes ago, Kendorr said:

And I've just found that a very good mate has one with a couple of chisels that will be borrowed for next Thursday. I'll let you know how I get on.

 

Thanks again for all the replies.

I break a lot of concrete in my day job.  SDS is your first stop as suggested but don’t assume they’re all the same. You need the heaviest one you can find.  If your borrowed one just taps and nibbles at in then buy the heavier Titan branded one at Screwfix.  They’re brilliant for the money.  Set of DeWalt chisel bits if it doesn’t come with any.  
 

Next up after that is the big boys breaker.  I and half the guys I know swear by the Macallister/ Titan one. It’s an absolute beast and at £150 ridiculously good value.   Nothing it won’t get through but go easy if you try it and only work parallel to the steel.  Point it down and you’ll find yourself through the bottom of the hull.  

[magnetman]

Thinking about the hammer thing might it be worth making up some sort of sledgehammer 'see-saw' arrangement by lengthening the handle maybe with a scaffolding bar then lind it up, rest it on a pivot and jump up and down on the other end of the handle? 

 

I suppose it might break the handle orf. 

 

9 inches seems a bit low to be able to swing it manually under the Boat. 

 

Percussion on the baseplate seems to be an interesting possible option to loosen the concrete if you could hit it hard enough. 

 

 

 

 

[Peugeot 106]

How about building a small fire underneath the boat. Would that be enough to break the bond between the concrete and hull. Might not be a good idea if there is a lot of bitumen about but you could do a small test area to see if spread of flame was an issue.

I’ve never done this and it’s only an idea before someone shoots me down……..in flames

[Jon57]

11 minutes ago, Peugeot 106 said:

How about building a small fire underneath the boat. Would that be enough to break the bond between the concrete and hull. Might not be a good idea if there is a lot of bitumen about but you could do a small test area to see if spread of flame was an issue.

I’ve never done this and it’s only an idea before someone shoots me down……..in flames

How about a big speaker attached to the base plate and play some very loud heavy metal music. 😁

[Kendorr]

1 hour ago, Peugeot 106 said:

How about building a small fire underneath the boat.

Thanks, but I think I'll give that one a miss for now.

[Peugeot 106]

1 hour ago, Kendorr said:

Thanks, but I think I'll give that one a miss for now.

I probably would too unless I was really stuck. We used to light a fire underneath a JCB every morning when it was frosty to ungum  the diesel. The driver never gave it a second thought and it seemed to work and didn’t seem to damage anything as long as the hydraulic hoses were avoided. At least you shouldn’t have any hoses or gaskets on the baseplate. It was on the top of Bowes Moor though.

 

Whatever you do don’t bash too hard. Something will give and it may not be the concrete

 

Explosive charges are often used for breaking up concrete but they wouldn’t be my first choice either!

 

Have a happy tapping Xmas. It’s probably going to turn into one of those mindless jobs. Both of you know it’s going to come off but neither of you knows when!

[BEngo]

The OP said there was water oozing out from under the concrete so I guess any steel/concrete bond is not that strong.

 

N