At the end of a project, I asked that a washing machine box be installed. It was installed only 28" off the floor. Is this going to create drainage issues? Can I compensate for the lack in height of the drainage pipe? All washing machine installation instructions I see suggest minimum standpipe height much higher than this.

The code says that there has to be 18 - 30 inches from the outlet box to the trap, that the trap has to be at least 5 inches above the floor. 28 seems to be enough room to accommodate these 2 rules.

A little bit above the washer, typically 42, seems to be the standard. Below the washer blocks access: you have to move the washer to get to it. Is it to the side of the washer?

The vent can't route horizontally until it's at least 6 above the flood-level-rim of the washer, so you'll have a tall vertical vent pipe just after the trap.

It seems weird to me.

I moved mine twice, so it isn't a huge deal.

the length of the pipe from the box down into the trap is what we need to know.

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..... All washing machine installation instructions I see suggest minimum standpipe height much higher than this. .....

You already know the answer to your question.

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638