Blocking gap.

'Morning all!
For those who haven't read my previous post.... I have an old concrete triple laundry trough which I will be cutting down to a double as a temporary fix until the laundry gets a total make-over. As suggested I will be cutting it with a 9" angle grinder with a stone (couldn't find the masonary disc at Bunnings) cutting disc.
So here's my next question.... On closer inspection it seems the trough has a false floor, all three of the sinks have a drain, but all drain under the false floor to a main drain in the centre sink. So when I cut the end sink area off there will be an open space at the bottom (between the false floor and the "real" floor), approx. 5cms wide and 40cms long. Now I need some easy suggestions as to how to block up the gap, remembering that any product used will come into contact with water.
Thanks in advance for your advice.
-mrsxtro.

You could fill the gap with a timber wedge to just below the edge and sikaflex flush to the edge if it is only temporary, or sikaflex a piece of alum flat bar across it. I don't know how durable space filling foam would be or if it will be w/p. Or if you want to make it two tubs, just cut the divider out between twoof the tubs - now that is the Irish in me speaking out ;)

Cheers
Michael

Thanks for the advice, Michael.
I want to cut off one end so I can put the washing machine back against the wall rather than sitting in front of the trough (the triple trough takes up the whole of the wall space).
I checked out the expanding foam stuff at Bunnings. It says it is suitable for internal and external applications and is water proof so I am going to give that a go... if it can handle weather outside then I reckon it can handle a little water. It will not be continuously immersed in water, just splashed when the washing machine drains in to the sink. And it is only a temporary measure so if it fails in a couple of months that will be fine.
Anyone have any experiences with expanding foam they would like to add?
Thanks for your time.
-mrsxtro.

While you have the grinder and cutting disk cut a section from the side/end of the third tub to fill the gap and seal around it with silicon (silastic)

Should surfice until re make of laundry



The trouble with life is there's no background music.

If you go with foam option make sure when you fill the gap you dont block the drain hole. The foam will tend to expand along the cavity so don't be too generous. I would also like to add that my previous experience of those foams is that they will actual soak up water if they are in continual contact with water. We used to build fibreglass canoe and used that for floatation and found that over the years of use the canoes were getting heavier and heavier. Should be okay for what you want but a bit of something cut to size and siliconed in would also do the job.

Jon