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bln
06-04-2006, 07:20 PM
I have a client who has a limestone retaining wall (big ledge rock) with cracks in the rocks. I was wondering if anyone has or knows of a method of filling in the cracks. I was thinking of caulking the cracks and spreading limestone dust over the cracks. let me know what you guys think.

Squizzy246B
06-04-2006, 08:44 PM
I have a client who has a limestone retaining wall (big ledge rock) with cracks in the rocks. I was wondering if anyone has or knows of a method of filling in the cracks. I was thinking of caulking the cracks and spreading limestone dust over the cracks. let me know what you guys think.

G,day, Limestone is not so hard to re-point. If the wall is dry stacked then there is nothing you can do (that looks good) short of replacing those stones. The trick is to make the cracks look like an intentional mortar joint (if the wall is a mortared wall). The cracks are usually from lack of compaction when the wall was built and they may continue.

Take a small axe and chip out the cracks about an 1" to 2" deep. We usually pressure wash the wall at this stage to clean the joins and the water also helps even out the moisture content.
Make a mortar mix. Standard ratio, we use 1 of "Brickies lite" to 5 of yellow sand. You obviously can't use grey cement. Use a 10" or smaller pointing trowel to sling the mud into the cracks. You want to overfill the crack leaving the mortar proud. Try and create a little pressure in smoothing the mud into the crack but it doesn't matter if there is mud over the face of the stone.
Leave the mortar unitl its firm, usually an hour or two on a warm sunny day.
Take a fine wire brush and then brush out the excess mortar with the brush until you think it looks OK.
Then take a soft brush (like a broom head or bannister brush) and a gloved hand and smooth up the repair. You may have to wait a bit longer for the mortar to cure. If the soft brush leaves brush marks its too wet. As you brush it up wipe limestone dust into the mortar using your gloved hand.
The mortar will take some weeks to even up in colour and will always appear as a mortar joint.

Thats about all I can offer without a pic of the job.

Good Luck

bln
06-04-2006, 11:08 PM
Thank you for your input. but this is not a morter wall. The wall is ledge rock, 700-1200lbs stepping stones.

Squizzy246B
06-05-2006, 06:35 AM
Thank you for your input. but this is not a morter wall. The wall is ledge rock, 700-1200lbs stepping stones.

Well then, rip em out and bang in some new ones. We handle stones to 1800lbs with our Kubota 161-3 and sometimes bigger. But some pics would help.