Stone cap installation

[Tom Rees]

Every time I see this installation the mortar is cracked and the stones are loose. Can anyone provide a detailed installation manual of how to properly install stone around a column like this? Thanks!!

[stanley frost]

Needs an isolation joint between the stone and the wood. The dissimilar materials will expand and contract at different rates and the mortar will always crack

[Scott Patterson]

I don't know of a published detail but,.....

IMVHO, the mortar joints are too big. Honestly I would not even have mortar on the edges that contact the wood. The mortar is the weak link in the design and those caps show poor planning. Why would you have three solid pieces and then two pieces for that one side.... The less mortar the better..

[Jerry Peck]

Mortar is not compressible or elastic - a compressible and elastic material needs to be used there.

Could use a sealant or a "gasket" (for lack of a better term).

[Tom Rees]

Jerry what about some kind of flashing at wood post to prevent water entering between stone and wood? Could you mechanically integrate a flashing into the post? Would be ugly but effective. I found a couple of installation manuals that recommended leaving the mortar lines in a channel (concave) shape and filling with a water proof sealant. Your thoughts.

[Jim Robinson]

Agreed. I see it about once a week, and it is rare if it is not already cracked. Probably just not a great idea to begin with. I recommend silicone at the post, but the mortar is a different story.

[Jerry Peck]

Jerry what about some kind of flashing at wood post to prevent water entering between stone and wood? Could you mechanically integrate a flashing into the post? Would be ugly but effective. I found a couple of installation manuals that recommended leaving the mortar lines in a channel (concave) shape and filling with a water proof sealant. Your thoughts.

Tom,

I thought about a flashing too, but that would mean violating the integrity of the post and is surface by saw-cutting in a slot for the flashing. The saw cut would also provide a way for moisture to wick up into the wood above and below the flashing - not a good idea was my conclusion.

The above is presuming the post is a solid structural post, if the wood wood is just "wood trim" around a smaller structural post, then, sure, treat it as a through-wall over brick veneer and attach the flashing to the interior structural post (to make sure the flashing does not move), angle the flashing down to and over the stone (the gap between the stone cap and the inner structural post does not need to be filled now), and make sure the end of the flashing is bent down slightly to created a rain drip edge to prevent water from wicking back up under the flashing - then install the "wood trim" over the inner structural post down to, but not touching, the flashing (leave at least a 1/4" air gap - not sealed, no caulk, open for ventilation).

[Mark Reinmiller]

Stanley and others are correct. Backer rod and polyurethane caulk between the column and stone would be far better than mortar. Not using stone in an application like that would even be better.

Another option would be a solid stone top and terminate the column at the top, but then you would need to anchor the column to or through the top and there are few post bases that would look ok for this use.

[Eric Barker]

Another option would be a solid stone top and terminate the column at the top

In my book that's the only option if it's to last. Wood going down into anything is bad news when it's a wet environment.

[Jerry Peck]

Another option would be a solid stone top and terminate the column at the top, but then you would need to anchor the column to or through the top and there are few post bases that would look ok for this use.

In my book that's the only option if it's to last. Wood going down into anything is bad news when it's a wet environment.

The problem with that option in many areas, especially high wind event (hurricane) areas and shaky earth (earthquake) areas is that there is now a hinge joint in that supporting column at the top of the stone cap, and likely a limited strength connection to it too.

[Mark Reinmiller]

The problem with that option in many areas, especially high wind event (hurricane) areas and shaky earth (earthquake) areas is that there is now a hinge joint in that supporting column at the top of the stone cap, and likely a limited strength connection to it too.

In that case, the masonry column would need to be reinforced and tied to the footing. Avoiding the stone altogether would be best. Surrounding a wood column with masonry is only going to end bad for the wood and masonry.

[Vern Heiler]

Looks like pressure treated timber to me. That stuff twists and bends like a dogs hind leg as it dries. Elastomeric isolation joint (and a big one) is the only answer in MHO.

[Bob Harper]

Lally column on proper footing. Bring stone up then sheet lead cap with sleeve turned up snug to column. When you lay lime mortar bed for cap stone, use string in mortar to form channels for drainage. Pull string leaving channels open. One piece cap stone with center hole about 1/2" larger than column OD. Fill gap with backer rod and polyurethane caulk. Construct faux boxed column with bottom end grain cut on bevel to form drip edge and seal with oil based primer x 2 coats. Install wood with capillary break to stone slab.


Or, just run the d@mn stone all the way up.

[Eric Barker]

The problem with that option in many areas, especially high wind event (hurricane) areas and shaky earth (earthquake) areas is that there is now a hinge joint in that supporting column at the top of the stone cap, and likely a limited strength connection to it too.

No disagreement on that. Some designs are just plain wrong from the get-go and leave few / no options for easy correction.

[Jim Robinson]

[QUOTE=Or, just run the d@mn stone all the way up.[/QUOTE]

I like that idea the best.

[Vern Heiler]

I like that idea the best.

Our job is not to design the look of the home; that fight requires a marriage license in most states

[Jerry Peck]

Our job is not to design the look of the home; that fight requires a marriage license in most states

Maybe that is a result of a marriage comprise: I want the stone all the way up! And I don't want ANY stone at all!

Two days later ...

Tell you what, honey, how about if we only put stone up to about this high?

Okay, whatever you want. (We all know that is something which will come back to haunt us years later when we least expect it ... )