Expert: Dan Griffin - 12/12/2007

Question
I am planning on building a 1960 sf home in Central Texas on flat land. Soem builders have told me it is better to construct a concrete back porch during the house building so it can be attached to the house slab. Some say build it later so I can better insulate the slab from the house concrete since concrete is a big thermal conductor. Can you please help me sort this out?  Thank you. Bill

Answer
I can see no reason to pour a porch slab with a house slab, It would violate most of what I know for several reasons.  Exterior concrete will react to temperature extremes quite differently than interior concrete, the movement will break the concrete there anyway.  I agree totally on the thermal break.  I assume we are talking about a 4 or 5 foot wide landing and a few stairs going out the back door.  I would dig and pour the footing for a porch and stair with all the other footings.  I am guessing that it won't be long before you want a deck or patio and may find you want to remove the porch and stair to make that plan work better.