Drainage quandry - To jackhammer or not to jackhammer

[baffledthebuilder]

I want to replace my patio-unfortunately its surrounded on three sides and I'm concerned about run-off and pooling. The patio is an 8M x 3M rectangle with the long sides comprising of the house wall and a retaining garden wall, one short side is my nieghbours extension the opposite side is open to the drive. After removing the old patio we found a concrete base had been layed and after checking the levels in both directions we discovered that the base runs diagonally out of level with the only drain ( this is situated in the corner with our house wall and the drive and appears to be the highest point by about 25-30mm). We have 150mm - 200mm between the base and our house wall DPC and about 250mm on the nieghbours extention wall DPC.
My main fear is that if I lay a new patio as is, any run-off will pool between the garden wall and my nieghbours extension the only other sollution I can think off is to lay the patio sloping towards my house wall and install a proper surface drain parallel to my housewall running off into the existing drain, or, jackhammer the concrete base up and start from scratch - something I'm trying to aviod as it appears to be very thick in places ! Any ideas please

[DNgroundworks]

Could do with some pictures! but if the distance between the concrete and the DPC is 150mm, putting slabs on top of that will reduce that measurment to around 100mm ish, which aint good (ideally needs to be 150mm from finished level to dpc)

I would proberly take the concrete up, or like you say install a linear drain, be easier to say with pictures.

[baffledthebuilder]

Thanks for the advice I think I'm gonna rip it up! What size jack hammer do you recomend and are the heavy duty electric ones any good.

[msh paving]

hire a beaver powerpack and hammer from hire centre, far better than a leccy one MSH

[baffledthebuilder]

cherrs guys i'll keep ya posted:)