heating post tension slab foundation

huangyhg

heating post tension slab foundation
i just bought a new house with a post tension slab foundation.  the builder installed an electric heater in the garage and says i need to run this when the temperature is below freezing to protect my foundation.  does the makes sense?  can anyone tell me the reasoning?
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certain things should have been done during construction of your unheated garage slab to help prevent frost heaving around the edges. this should include a turndown or footing below frost level at the edge of the exterior and insulation beneath the slab if required. there are also other things that can be done. what should be done depends on your location.
maybe your foundation was not properly constructed for an unheated slab and he thinks he is trying to make up for that with the electric heater (costs you money for now on)? or maybe it was done appropriately for your area and he is trying to be extra careful. i would ask to see drawings of the garage and check out what was done at the foundation. make a copy and get an opinion of the drawings from another builder or engineer that works in your area.
of course that still doesn't mean he followed the drawings, but it is a starting point. if you still feel uneasy about it, you should consider getting an inspector to look at what was done at the slab perimeter.