Wall to wall carpet is sliding

I just had new carpet professionally installed in my house. On the stairs and upper levels, the pad was stapled to the floor and everything is great. In the basement, the concrete slab is covered with an epoxy waterproof coating that is very slippery unless you are wearing rubber soled shoes. I noticed that the pad was slipping around when I walked on it before the carpet went down. The installer did not glue the pad to the epoxy floor (I did not instruct them to because I trusted that they knew what they are doing, and I thought maybe the problem would go away once the carpet was secured to the tackless strips). Unfortunately the carpet moves laterally when you step on it. It has more give the closer you are to the center. This is a large room, 16 x 24, so plenty of carpet to stretch. The installer stretched the carpet properly to get it on the tackless strips but it still moves around. This is a natural wool carpet with a jute backing - it does not have a stiff glue backing that limits stretching. I am pretty sure this is going to cause excessive wear to the carpet if it is not fixed. Plus it is unsettling to feel the carpet move underfoot, like an oriental rug will slide on a hardwood floor if it has no rubber pad under it. The installer is claiming that he does not use glue unless the customer requests it. Yet, I did not request that staples be used on the upper floors and the installer put down staples to secure the padding.

I would appreciate feedback about whether it is reasonable to expect that the pad be secured to the floor, and whether this slipping problem is likely to cause excessive wear.

Thanks,
Bubster

Thanks for the response. Yes, the rest of the install was good.

The reason the slipping is likely to be a problem, in my non-expert opinion, is that the carpet is being stretched sideways every time someone walks on it. It’s not just sliding, like a throw rug sliding on a hardwood floor. It is sliding while being restrained at the edges by the tackless strips, which stretches it. I foresee it getting loose over time, and no longer lying flat. Plus, if the stretching eventually adds a foot of width to the carpet, then the slipping will be worse.

I would be curious to know if any pros believe it is unnecessary for the pad to be secured to the floor. If that were unnecessary, what is the reason for installers stapling pads to wood floors. I assumed it was to prevent slipping and can’t think of any other possible reason for stapling.