I recently did a job that included block columns w/mfd stone and a 24x24x2 bluestone cap. I am having a prob with one of the bluestone caps sticking to the top column (using type S). Am wondering if bluestone needs to be washed or otherwise prepared to be mortared? Any thoughts?
Mortar Sticking to Bluestone
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wow, what a gem of wisdom....
can you tell from the finished product how badly we needed to hire a "real mason"?
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Aside from making sure the bottoms are clean and washed, we always use a bonding agent painted on, and used as an additive in the mortar. The bottoms of sawn bluestone are slick as glass....
Yup...and ALWAYS clean ANY stone that gets laid in a bed. You have cutting slurry, job dirt and who knows what between you and breaking surface tension.
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bluestone
I have seen the same problem. Bluestone will swell with moisture and warp. Most people don't think that stone will warp, but it definitely will. Stones that are blue or green in color seem especially susceptible. You set them with wet mortar, they swell on the damp side and bow away from the mortar.
If these are just caps you might try setting them with a sealant joint (a good silicone) and no mortar. Hope this helps.
I have seen the same problem. Bluestone will swell with moisture and warp. Most people don't think that stone will warp, but it definitely will. Stones that are blue or green in color seem especially susceptible. You set them with wet mortar, they swell on the damp side and bow away from the mortar.
If these are just caps you might try setting them with a sealant joint (a good silicone) and no mortar. Hope this helps.
Setting bluestone caps
For a stronger hold you could use a diamond coated grinding wheel to rough up the underside. Furthermore, you may decide to have rebar sticking up from the column and drill the stone so the rebar from the column fits in the drilled holes when you set the stone. Of course the holes don't go all the way through the stone. Slurry the underside and pack the holes before setting. There are also mounting kits used for setting countertops. Do a google search for Regent Stone Products, visit their site and talk with their knowledgeable sales people. They will send you the tools to get it done.
For a stronger hold you could use a diamond coated grinding wheel to rough up the underside. Furthermore, you may decide to have rebar sticking up from the column and drill the stone so the rebar from the column fits in the drilled holes when you set the stone. Of course the holes don't go all the way through the stone. Slurry the underside and pack the holes before setting. There are also mounting kits used for setting countertops. Do a google search for Regent Stone Products, visit their site and talk with their knowledgeable sales people. They will send you the tools to get it done.
Just an observation but I have noticed that the masons around here get a little pissy when they read a thread about someone mixing mortar who is not a mason. I have a friend who is a mason that acts the same way.
So I'am wondering is being self righteous a requirement on your license application or am I missing something.
No offence intended just an observation:whistling:whistling
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Laborers or tenders usually mix the mortar. And I do not wire an outlet.
I know this is an old post but another way of increasing the holding strength, in addition to washing the stone, using bonding agent, and scarring the stone. Is to cut a slot into the bottom of the stone the length and thickness of a heavier gauge wall tie. Tap the wall tie into the stone so that it is standing on edge and sticking out only slightly less than the bed joint thickness. This will help hold against some lateral pressure.
While it is not on the license, it is often found on the job. Some would say I am self-righteous, I would argue with the self portion...:w00t:
It can only be said that one is a primadona if they don't have the skills and authority to back it up. Since most masons have both the skill and experience to be the final say on just about anything, I would say that your observations are consistant with actual reality.:clap::clap:
I rest my case!:notworthy
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