We had a garage fire the garage was 32X48 We have been told we can lay a new 3" concrete on top of the old after the fire. Then we were also, told that we could build the building on the old concert and pour the new concert inside the build on top of the old concert. we live in northern MN so we also have a weather issue. Could you please help ?
Thanks you
Grand Forks
Both options seem reasonable.
I am assuming that the fire was not intense enough to cause the concrete to spall and/or develop large cracks.
Placing a 3 inch topping on the old concrete sounds right, but make sure they use a 'bond-breaker' (slip sheet) between the old and new concrete. Otherwise, you will see old cracks transfer to the new concrete. Also follow all the normal procedures for new concrete as far as placing, curing and joints. A garage of that size should be divided into no less than 6 sections (15x15) using joints.
I assume that contractors in your area know how to deal with freezing temperatures. Placing the concrete after the structure is enclosed will help keep the concrete from damage by freezing.
By the way, is it really necessary to add concrete topping? Can't you clean the old concrete (acid etch or sand blast or bead blast...)to restore its appearance? Adding 3" of topping could cause problems with elevations at the doors.
Good luck.