making paving slabs waterproof

[amazondean]

Hi all.
I am after advice if there is anything that can be either painted or applied on top of a paving slab patio to make it waterproof. I have purchased a house that a previous owner laid concrete lintles across an old brick outbuilding when the roof was removed and then laid slabs on top to create a raised patio overlooking the city. Obviously water is penetrating the slabs and morter and running into the outbuilding rendering it useless as a store. Is there anything that may seal the slabs as i don't want the hassle of ripping it all off and was wandering if there is anything that would seal the patio from water penatration. Any ideas would be greatful.

[welsh brickie]

1.Cover the entire area in thick bitumin and then laying timber decking on top to protect it.
2.Lay a self level compound over it and tile the area.
3.Get a company to fibreglass over the area

[amazondean]

Thanks for that. Would the decking need to be fixed to the slabs or would the weight of the decking stay in place. The area is 2.2m x 3.2m approx

[welsh brickie]

you can place the decking on 4x2 treated timber bedded into the bitumin