Had a fieldstone walkway put in recently, roughly 16' long. It sits
on 2" crushed gravel, then concrete, then mortar. Mason used type S
mortar for higher strength. The jobsite is in the northeast (upstate
The mason cut expansion joints in there using a concrete saw. There is
roughly a 1/4" gap that has a depth about 2". I have masked and
caulked the gap with GE's silicone masonry grey-tinted caulk and it
looks good. However, I caulked the top and sides of the cut with the
thought being that should water get inside under the caulk joint and
expand, it woudl negate the effects of the caulk on top. SO basically
right now the entire cut is sealed from the elements from all three
sides. I am wondering if this was a bad idea. in the unlikely event
the concrete foundation shoudl crack and water should get inside the
small space, there is no way for the water to get out. Worst case
scenario, this happens during winter and the water freezes and cracks
the walkway. The last thing i want is for my nice new walkway looking
like crap after one winter.
I had considered this while I was caulking, however since the cut was
made by hand with a power saw, the depth varies and woudl not provide
guaranteed adequate drainage anyway. In other words, it could still be
possible that water could become trapped in the gap even without
caulking the sides.
I forgot to mention, a high quality stone sealant has alreadt been
applied over the entire walkway surface.
This was my first experience caulking a stone sidewalk so i wanted to
ask the gurus here if this was the best way to prepare this walkway for
the winters here in upstate NY.
I am confusted (but that's not hard). He made a 2" cut? How deep is
the stonework and concrete? Did he cut through to the bottom of the
concrete? On 16', how many cuts did he make?
I am probably wrong, but I thought an expansion joint had to go all the
way through the concrete to allow room for expansion. Otherwise you
are allowing room for the top to expand, but not the bottom.
Okay, I'll be quiet and let someone more knowledgable than me answer.
First of all an EXSPANSION JOINT is a joint (equall space) that is
through the entire masonry unit be it concrete, block, brick or your
What this obviously in experienced mason did was cut a "controll joint"
in your walkway. This type of joint you have seen as you walk down the
sidewalk in your area, its not necessarly a bad thing but it is NOT an
exspansion joint hopfully when the walkway moves it will crack here.
joint in your new walkway. Typically when doing real stone waklways you
do not put joints in..it simply is not necessary.
As far as your panic about the water issue relax lets go back to that
same sidewalk I mentiond in your area...those joints dont have caulking
in them and they are just fine...well most of them (I grew up in PA) so
I know the effects of winters on sidewalks.. but seriously if you look
at the sidewalks most of them are ok a few are bad right? Dont sweat it
it will be fine.
Just out of curiosity how thick was the slab the stone was set
on?...Thinner than 3 1/2" youve got more serious problems than the
joint 3 1/2 or thicker (NO INCLUDING THE STONE) just the concrete...you
should be fine.
THESE SEALANTS DO NOTHING other than bring out color of the natural
material in your case and protect the surface of man made materials
(color in concrete stamped concrete). It in no way protects your
masonary from cracks or other structurial weakness.
Thank you all for the quick replies.
Nowhere in his job quote did I see anything about cutting an control
joint. So imagine my surprise (dismay?) when I came home from work one
day and there he was halfway through his second cut on the beautiful
new stone walkway! I wish i came home sooner, or I would have had NOT
cut the control joint.
First, I'd like to clarify that I put sealer on to protect against
moisture, on the advice from the mason as well as some other people i
know who have had stone work done. Water is typically the precursor to
cracks, so i figured what the hell. I didn't want water seeping in
during winter and wreaking havoc. The sealer doesnt alter the look of
the stone (ie no 'wet' look).
Second, the underlying concrete is approximately 6-8" thick, excluding
the stone thickness and mortar bed. for pics:
third, I already caulked the joints prior to posting this, so leaving
the gap open isnt an option
here's a link to a picture of the caulked joints.
So as of right now, both control joints are still caulked on 3 sides
(top and both sides - the bottom doesnt cut all the way through the
concrete, just the mortar bed). I am going to leave as is unless
someone can convince me its a better idea to remove the caulking from
I woudl like to keep the caulk on top, since it does improve the
aesthetics of the walkway.
Nice walk, but dog looks pissed.
Control joints control cracking. They're a good idea. I don't think
calking will matter either way.
But control joints don't control expansion. Expansion requires room
for the walk to move. But I'm not sure your walk is big enough to need
any, esp. if there a bit of space at each end.
So in general, I'd say don't worry about it too much.
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