Mortar Joints On Top of Retaining Walls
JoeArchitect
| Posted in Construction Techniques on
I have a limstone cap top off a concrete retaining wall with a face brick veneer. The stone is steeply pitched like a gable roof with a 12:12 slope. The mortar joints between the stone caps is my concern. I specified epoxy mortar for the joint. If the mason did not use epoxy mortar, what can the mortar joints be sealed with to prevent moisture penetration at this point?
Replies
i'm not sure you want to seal them... i think that would trap more moisture than it would prevent... the limestone isn't sealed?
I'm thinking that you spec'd the epoxy so that the stones would never break loose and crash down?...
I have removed/reused alot of old cut limestone (prob have 30 tons in my yard now)
i've never had a problem getting the mortar off (i know not comforting) easier than clean'n old brick with lime mortar... but what seems to be a constant when they wanted something to hold... they cut grooves in the area to be mortared so as to provide some bite... most of what i have was placed 70-80yrs ago before they had any type epoxy...
limestone is a pretty cool/fun material... as easy to carve as wood... in fact i usually use wood working tool to carve it...
p
The building I currenty in has limestone caps on all the roof parrapet walls. In the past 10 years we have had all the head and bed joints tuck pointed.
Grind out the joints to about 3/4" to 1" deep. Brush and blow out the dust. Insert backer rod and caulk with a silicone caulk made by GE for masonry work. Tool the caulk with small metal paint spatula and xylol solvent. Sprinkle/dust mortar sand over the tooled joint and it looks just like a mortar joint, but will out last and perform it by 20 years.
Dave
I have done what the previous poster is talking about and also used epoxy mortar " what a messy stuff almost impossable to keep the masonry units clean",but somethong I have seen, is that epoxy mortar used with limestone --WILL-- make the limestone prematurally age at the head joints, the mortar joints looked fine, all most like the day they they were layed --BUT-- the limestone next to the e.m. was failing. I also have used a product called Frogskin sealer that lets water vapor escape but keeps water out on a number of restoration jobs, after about 15 years no call backs and as of last year one building in particular, is still beading water on the old soft bricks even10 years since application and no more additional damage.
Thanks, just the option I was looking for.
Check some supply houses for a douple diamond blade to fit a 4" angle grinder. Makes short work of cleaning out those joints. One pass is all that is needed for a 3/8" joint.
Be sure to get a good respirator for this type work. A dust mask won't get it. The silica and lime in the motar can cause some bad respitory problems in a very short exposure time.
Dave