Tiling on concrete beams

[Drdmwolf]

Hi there, I need some advice on replacing some decking with tiles. Current decking is on timber struts attached to concrete beams. I would like to remove the decking and then tile onto the beams.
Do the cavities need to be filled or more beams inserted to reduce the space between the beams? I’d prefer not to lay a slab as there are some pipes from a ground source heat pump that we may need access too.
See attached images.
Would appreciate some input and advice please.
Thanks
Dennis

 

[Edd The Tiler]

I'd say you need to lay a slab, but somebody else may have better ideas mate. Where abouts do the pipes you need access to run and could they be re-routed?

 

[Drdmwolf]

Thanks for the feedback. I would prefer not to lay a slab due to the pipes.
I was considering laying more beams to reduce the gap between the beams??