On Nov 2, 4:46 am, hands on wrote:
On Nov 1, 6:18 pm, Manster wrote:

hands on wrote:
I have 12 foot x 21 foot concrete patio that cracked down the middle
after 30 days of install thanks to Veranda Homes LLC of Wilmington,NC.
I tried to fill in the crack but it looks bad and the builder won't
fix it.

Why? Well I know why, he doesn't want to pay for it. Were any
expansion joints put in that slab? How thick is it? Did he adhere to
local requirements (if any) for mesh, etc? Many places don't have a lot
of req's concerning non-structural flat work, but it's a shot. I
wouldn't give up yet on making him tear it out and redo it.

No expansion joints. The crack is only 1/8 inch wide but it runs the
entire width. I tried that concrete patch in a tube but it looks like
crap.

Yes, there are two types of concrete: the kind that cracks and the
kind that hasn't cracked yet. Usually the standards for non
structural flat work is pretty low anyway, so I think it is a stretch
to get the builder to tear up and redo. If concrete guys had to go
back and replace every slab that cracked, that's all they would be
doing and the price of a pour would be astronomical. And why won't
the second slab crack like the first one? Cracks can be prevented,
but it takes a lot of money--it takes perfect prep work, rebar, strict
control of water content of the concrete, etc. Cost pressures don't
allow this on residential flat work. You see it in commercial slabs,
but look around and you still see some cracking. So unless the plans
included detail of reinforcement and prep of that patio slab, or
unless you specifically requested and paid extra for such work, your
builder could argue that the slab meets the standards of the trade and
he would be right.

Also, expansion joints wouldn't be used in the slab. They are used
where a slab is butting up to an existing structure, sidewalk, etc.
You are talking about control joints, which basically control where
the slab cracks. Usually, they occur every 12' (take a trip to your
local borg and you will see what I mean). On a residential slab, they
are typically sawed into the concrete within 24 hours of the pour.
They often don't work in my experience--you wind up with cracked
concrete AND saw joints in your slab. Did the blueprints specify
control joints?

I'd suggest two options: tile it (use a crack isolation membrane) or
live with it for six months and see if it still bothers you.