Hello I am a complete noob to the whole oven experience and eager to learn all I can to build a great piece. My whole concern before I even begin contemplating the design of my build revolves around a comment I read on the instructions for a barrel oven through brickwoodovens. It stated that it is not recommended to build the oven on an existing cement patio or slab due to the amount of weight it will be delivering to the cement. Is this a true statement or was it a general warning to avoid possible legal issuesI ask because I have mostly only pre-laid cement available to start a build and the area that could serve to dig is small and currently used to entertain my 2 year old baby girl and I just don't have the heart to take up space in her area. Also because this patio is in the back part of my home it has a pitch to help with water drainage, Is it possible to build on top of this cement and later compensate for the angle to make a level surface. Please help as I am a complete newbie and while the info on this forum is great many of the terms are yet confusing and a bit overwhelming. Thank you!