Removing Concrete 'Mortar' from Exterior Stone Wall: Help

[Rich1972]

Hello all

Has anyone had any experience with a similar situation? The walls of the my house are limestone and at some point in the last 30 years a new window has been added to the kitchen. Unfortuantely, instead of repointing the exterior wall with a lime-based mortar, the previous owner has slapped on concrete instead!! I'm having a devil of a job trying to remove it. My hammer and spike don't make much impact and it just tends to splinter rather than coming off.

Does anyone have any recommendations as to the best way to approach the situation?

Thanks [:)]

Rich

[Anton Redman]

SDS Drill set to chisel. Small angle grinder with cutting disk. Hours of hard graft.

Bon courage.

[Rich1972]

What is an SDS drill? [8-)]

Edit: Ah, ok. It a special hammer drill [:)] I will try and get hold of one and give it a try.

[AnOther]

I've seen this cement infill on many many properties, it's awful and IMO completely destroys the look of a house.

I wish you the very best of luck, you've got a lot of hard tedious work ahead of you but I'm sure it will be worth it in the end [8-|]

 

[BIG MAC]

Try to get into the limemortar beneath in the joints and try levering the conrcete slightly it may come away in largish sections if the wall was not prepared well before. Try effectively to work on  the joints in the stone work below leaving yourself with leaves of concrete on the face of the stone which may shear off when chiselled.

[TroisChatNoir]

this is something I regularily get asked to do, cut into the concrete in a checkerboard pattern as deep as you can with an angle grinder with diamond disc then knock it all out with an SDS hammer & small chisel point. when you have a nice deep "slot" back to the stone then you can infill with stone to make an invisible mend.

In my trade there is no substitute for Hard Graft unfortunately!

[Chancer]

As someone who will soon have to have Carpal tunnel operations resulting from overabuse of SDS hammer drills may I make a suggestion that I have recently found which to my exasperation has proved the futility of using SDS machines for the above task.

I started using a cheap air chisel driven by my compressor, not only is t far lighter and less fatiguing to use but probably about 20 times more effective. I have used it to reclaim bricks (removing old mortar) and to make several brickwork openings in 11 inch solid brick walls, both of which I have done many times before with SDS but never again.

I have seen the "burin pneumatique" sets for around €30 at Brico-Depot etc, if you dont have a compressor you may be able to borrow one and pay for it by donating the tool after the loan.

Oh and I also find that there is less kickback from the percussion action than SDS so it causes me less trouble but this is not empiric eveidence so I would wear thick padded gloves.

[Gluestick]

I totally agree, JR.

A small pneumatic hammer has a much higher strike rate and whilst it has far less mass, the speed and strike rate are far more effective.

I always kept an old air hammer for rough jobs in the workshops: including digging up concrete floors for Rawlbolts when fitting machines and equipment and even used it once to dig out a  20 foot long channel in the concrete floor for a new small overflow drain!

 

[TroisChatNoir]

Whilst I can't fault your statements re air tools to balance a decision on which way to go the choice is entirely personal, a purpose made SDS "type" hammer such as a K&ngo or similar is far more useable by the general public, air hammers require a compressor, lengths of purpose made hose & fittings, specialist breaker guns and tools if you can lay your hands on them great, whereas an electric breaker requires only a plug socket and an extension cable and sometimes a generator if no electric on site.

good luck, its not how hard you hit it but knowing just where to hit thats the secret. I've seen people take days to knock out a great big hole when a couple of hours & some intelligence is all that's required

[Chancer]

[quote user="TroisChatNoir"] I've seen people take days to knock out a great big hole when a couple of hours & some intelligence is all that's required
[/quote]

Well you might have stopped and told me[:D]

Apart from being much more powerfull and effective it is the much lighter weight that makes the air chisel my weapon of choice, if I use it for the same period of time I wil do more than 5 times the work and feel 10 times less fatigue.

In my previous business I frequently had to cut channels and holes in concrete driveays, I could usually use my petrol disc cutter and bar à mines (forgotten what it was called in English!) but when that wasnt enough I would hire an electric Kango breaker.

One time even this bounced off as the roadway was built by/for the R.A.F. in WW2 to be used as a secret air base, I hired a petrol engined hydraulic breaker, the power unit was really heavy and needed two people to load/unload from my trailer, the working end however was a fraction of the weight of the Kango which of course has the motor etc built in, and again was far more effective, the concrete may as well have been butter.

[AnOther]

I wonder if a needle gun might make a good weapon for the job ?

[IMG]http://i127.photobucket.com/albums/p123/biskitboyo/needle-gun.jpg[/IMG]