"Lee Nowell" wrote in message
...
Hi All,

A friend has an old indoor swimming pool which he got converted into a
playroom. They removed the inner lining and constructed a deck over
the pool enabling him to use the old pool below as a good storage
area. This worked a treat until the winter rains came and it
transpired that the water table is very high and the pool was not
tanked on the outside. Net result water is seeping into the storage
area and stinks!!

Ordinarily, he would fill it all in then finish with a DPM and
concrete slab but this is going to cost a fortune - mainly because of
access/ distance issues to transport the gear to the pool. As a
cheaper option, a builder has suggested dropping the timber deck 100mm
adding some DPM/ sealant on top of it and pouring a 100mm slab of
reinforced concrete. I guess he would have to dig some of the edging
away to ensure the slab sits on the pool side walls. Would this
approach work?

My initial thoughts were...
1. water will still come in below the decking as normal but in theory,
you won't smell it if the slab is fully sealed - seems likely to fail
in the future.
2. during the wet months, water will come in from the "force" of the
surrounding water table. Will this go away in the drier months or just
sit there? The side walls are made of concrete blocks. Even if it
does seep back into the soil, won't it leave a horrible slimy residue?

I would love to hear your thoughts on this approach and whether you
can think of any other option? He did look at tanking it (in the same
way as you would a cellar) but again this was too expensive.

Expanding foam is light and could be removed if he wants a pool back.