Stone Separation


  #1  
Old 11-19-20, 03:27 PM
Z
Member
Thread Starter
Join Date: Jul 2014
Posts: 9
Received 0 Votes on 0 Posts
Stone Separation

My google-fu has failed, though I'd be surprised if this was not asked before, and for that, I apologize.

I have a stone patio and fireplace in my backyard that has some of the flat top stones that have come separated from the mortar completely.

What is the proper way to fix this?

Do I have to remove the old mortar with a chisel? If so, I assume it needs to be a mechanical device.

Also, do I use the same mortar for the joints between the rocks? And what do I use between the stone and the wood?









 
  #2  
Old 11-19-20, 03:31 PM
Marq1's Avatar
Member
Join Date: Sep 2016
Location: USA MI
Posts: 7,501
Received 531 Votes on 491 Posts
For the stone on stone, remove any loose material and Id use a latex fortified large format thin set .

For the stone and wood, I bet that has something to do with the wood swelling, Same thin set but need to have a larger gap to the wood which would then be caulked! If there was a way to install some flashing that would help but it's not going to look so great!
 
  #3  
Old 11-20-20, 05:08 AM
P
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 25,511
Received 962 Votes on 883 Posts
I would also remove the old mortar. If you don't your new mortar will make the stone sit higher than the others since you would have two layers of mortar. Before mortaring wash the stones off to remove and dust & dirt. I like a richer (more cement) mix and/or you can use a latex modifier like Marq1 recommended.

Your stone around the wood column is not a good idea. First, it's very bad for the wood. It will hold moisture around the wood and not allow it to dry causing it to rot prematurely. Also, as you can see masonry (rock & mortar) doesn't stick to wood very well. Then as the wood swells and shrinks with changes in moisture it breaks away from the masonry. If you've just gotta keep the rock around the wood column you'd be better to mortar the cap stones in place with NO mortar next to the column. Then use a flexible caulk for that gap.
 
  #4  
Old 11-20-20, 08:48 AM
Z
Member
Thread Starter
Join Date: Jul 2014
Posts: 9
Received 0 Votes on 0 Posts
Thanks, I've never tried to remove mortar like this, so not sure how big of a job that is and what special tools I'll need other than a chisel and hammer.

Between the stone and the wood is a flexible caulking of some sort.
 
  #5  
Old 11-20-20, 08:59 AM
P
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 25,511
Received 962 Votes on 883 Posts
For removing mortar I use a mason's hammer and a chisel. I set the stone on a board or on dirt (not anything hard like concrete) to provide some cushioning for the stone you want to save. For removing the big stuff I use the chisel end of the hammer. You whack at the mortar at a shallow angle along the length of the stone. That way your energy is going into the strongest direction of stone to reduce the chance of breaking it. For finer work I use the chisel and hammer end of the hammer to chip away at the mortar. You don't need to remove all the mortar but you should get rid of most. It's OK if there is a layer of old mortar firmly attached to the stone.
 
  #6  
Old 11-20-20, 09:52 AM
Z
Member
Thread Starter
Join Date: Jul 2014
Posts: 9
Received 0 Votes on 0 Posts
Thanks. All the stones that have come loose have almost no mortar on them. I'll be removing the mortar from the base underneath these cap stones. I just don't want to damage other stones in the process of removing it.
 
  #7  
Old 11-20-20, 10:36 AM
P
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 25,511
Received 962 Votes on 883 Posts
It's better to use smaller tap, tap, tap hits than one big/hard whack which can break a stone loose or crack it in half.
 
  #8  
Old 11-20-20, 11:05 AM
Z
Member
Thread Starter
Join Date: Jul 2014
Posts: 9
Received 0 Votes on 0 Posts
Would it help to cut grooves across the top of the mortar with a dremel ultra saw, similar to what one would do when cutting mortises in wood to allow for chipping out the mortar in smaller sections?
 
  #9  
Old 01-11-21, 02:26 PM
Z
Member
Thread Starter
Join Date: Jul 2014
Posts: 9
Received 0 Votes on 0 Posts
As I looked at this closer, I see some of the wood is rotted on the 8x8 post. Is there something that I need to do to treat this prior to fixing the mortar and caulking?


 
  #10  
Old 01-11-21, 03:00 PM
P
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 25,511
Received 962 Votes on 883 Posts
The stone work should not have been built up around the post. It's holding moisture against the wood causing the rot. Makes you wonder what the rest of the post looks like further down.
 
  #11  
Old 01-11-21, 03:52 PM
Z
Member
Thread Starter
Join Date: Jul 2014
Posts: 9
Received 0 Votes on 0 Posts
I agree, but the only option is to tear it all down and rebuild from scratch each post and rebuild it. I assume that would require jacking up the roof of the patio, removing the post. Removing the stones is probably not simple, other than just breaking them off. Then to find replacement stones that match. Two other posts in other areas still have caulk and no loose stones, but then can't say what's below.

I don't even know what to guess the cost of that work would be. We just bought this home in July.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description: