Laundromat Floor Inspection/Design

[kxa]

I am involved with the structural integrity evaluation of a Laundromat that, of course, has extensive rotting in the floor wood joists due to water and moisture. The steel girder supporting the joists does not look much better. The washing machines and dryers are placed over a 1’ thick concrete slab. The slab which is only about 5’ wide is supported by wood floor joists and several concrete columns that are slanted to absorb the vibration from the washing machines when they go into the spin cycle.

Does anybody have any experience with these types of structures or is aware of any references that can help with the inspection and design of a Laundromat? Any help is greatly appreciated.

 

[JAE]

Whether it is a laundromat or any other use space, the investigation of the floor system would essentially remain the same. Water damage to wood is not good, of course. The wood may have all sorts of inherent distress such as dry rot, lowered modulus, and reduced capacity to take stress. If there is currently any significant sag in the wood (stringline the joists to see) that would indicate long term creep and possibly these kinds of damages.

The concrete topping probably acted as a hard sponge to hold water until it could move into the supporting wood...again, not a good scenario.

It may be that the floor system would have to be replaced. Alternatively, supplemental wood joists can be sistered up to the existing to provide 100% of the capacity, ignoring the older wood.

 

[MiketheEngineer]

And most codes demand treated wood in contact with concrete...