I am not a mason so I need some advice on a job if it is feasible engineering wise.
I have a client with an existing patio 12 x 20. They want to make it 14 x 22 & 5″ higher before I add the Sunroom addition. Can I dig and pour a footing around the outside edge of the existing slab and then pour the additional 5″ of concrete over the existing slab patio. We are in the north east and am concerned with frost heave of the old patio slab. The client does not want to have to have the existing patio slab torn out.
Yes you can, thats what I plan on doing to my addition.
I'm a fool to do your dirty work.
Edited 8/20/2006 8:37 am ET by Stilletto
Is the current porch on footings or floating? If it's on footing, no worries. If it floats, and the new porch is unheated I would put insulation around the perimiter of the foundation and perhaps 1 -1/2" of foam over the old slab. This should help keep the slab from heaving. I would strongly suggest though that you put a clause in the contract about not being liable for any issues related to not removing the old slab, and understand that you are recommending to have it removed. Your client is trying to save money, it shouldn't come at your expense if there is a problem later. They will probably not have any problems, but make sure the risk is theirs, they understand it, and absolve you from responsibility.
Thank you for responding, and I will definitely take your advice