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Rock Breaking

Star How to get rid of a very large rock that is in an inconvenient place .


The problem

When digging the foundations for the main house a rock was found that was way too big for the excavator to move.

Footing Excavation 301 

Footing Excavation 302

Footing Excavation 303 

Felicity On Big Rock

Felicity On Big Rock 

Various methods

There are various method such as...

Wedge and feathers

Feather And Wedge Failure 

You drill 3/4" holes and then hammer them in in sequence.  The picture shows my attempt at using 3/4" wedge and feathers but it did not cause any rock splitting.  Each wedge with its two feathers costs about $12 and they are rarely reusable.  You would need hundreds of sets for a large rock.

Wedges and chisels in sawn slot

Diamond Rock Cutting Saw 

Use a diamond cutting saw to make a 3" deep groove and then hammer masonry chisels into the groove to hopefully get the rock to crack.  The technique has some potential but in my case the rock was just too big.

Jack hammer

Dave Jack hammering

A jack hammer is a useful tool for dealing with very hard ground and for concrete, but is no match for a large rock.

Expanding resin

The technique was not tried.  It requires drilling a large number of 1.5" holes and filling them with expanding resin.  The resin is fairly expensive and so is a 1.5" masonry drill bit.  With the right equipment it is ok drill a hole, but it takes a long time to drill the large number of holes. 


This was not tried because of the large number of regulations and restrictions.


This was found to be by far the most effective method.  You build a very hot wood fire to thermally stress the rock to cause it to crack.


Fire is best method

Fire By Rock 101 

Fire By Rock 102 

Fire By Rock 103 

Fire By Rock 104 

Rock After Day 101 

Rock After Day 102 

Site Rock Burn 

Site Rock Burn 

Fire By Rock 201 

Fire By Rock 202 

Fire By Rock 203 

Fire By Rock 204 

Rock Burning Continued 01 

Rock Burning Continued 02 

Rock Burning Continued 03 

Rock Burning Continued 04 

Rock Burning Continued 05 

Rock Burning Continued 06

Rock Burning Continued 07 

Rock Burning Continued 08 

Rock Burning Continued 09 

Rock Burning Continued 10 Water 

Rock Still Burning 

Site Rock Still Burning 

Rock Getting Off Side Top 

Rock Burning At Dusk 

Rock Fire On Top 

Rock Getting Top Off 

Prying Rock

Rock Burning Continues 

Rock Part Gone 

Rock Burn Nearly Finished 

Burn Rock Last Fire 

Site Last Rock Burn 

Once the rock is reduced in height and width such that it is no longer in the way it can be covered with soil.

Rock Covered With Soil 

The broken off bits of rock can be used to make a rock wall or rock garden or whatever.

Pile Of Burn Rock Bits