The acid will attack the lime in the concrete and break it up.
How to dissolve grout in drain pipe.
One option when dealing with a drain clogged with concrete is to pour muriatic acid down the affected drain.
Tile grout can present real problems if allowed to accumulate in your drain lines.
The other cause can also be tiler s grout which sits like concrete in the pipes.
I have been involved several times in the last 30 or so years where a tradesman has washed cement based grout down a stormwater or sewer drain expecting it to simply disappear never to be seen again.
Hot water will not work to remove grout.
Trouble is that it certainly was seen again.
Let it sit for two or three hours flush the drain with about 4 gallons of water then use a plunger to loosen the clog.
If the line is plastic you may be able to break up the grout and push it down to a larger line.
Most older sewer lines are made from clay and even most newly built structures with pvc drain lines eventually discharge into a city waste system comprised of clay pipes.
Clear concrete from drain pipes.
It causes blockages by settling in p traps and pipe joints and hardening into a clump.
We have septic and bathroom is small and no windows so don t want to use acid.
Grout doesn t dissolve.
Unfortunately concrete and grout are what we use to make larger sewer lines.
Tilers are meant to dispose of their grout in the bin but sometimes they can be lazy and let it fall down the floor waste or allow it to fall through the grated drain and this can cause major blockages to the pipe.
Grout from shower tile grouting project in second floor bathroom got into the drain in the fiberglass shower pan and pvc drain pipe is totally clogged.
You probably and hopefully have a large amount of sand grout stuck in the p trap if so your best bet would be to remove the p trap and give it a good thorough cleaning out in the yard with a hose.
While the trap is off you ll be able to inspect the tailpiece and the drain line as it goes into the wall and clean those up too if necessary.
Since grout sets up under water you may have to get a licensed plumber with powerful sewer and drain cleaning technology to try and clear the line.
Not sure how much is really in there but it took hours for the pan to drain after first shower after project.