Slab foundation building in Fairbanks AK - planned around the ground under your home

A slab is right for your lot when the soil, slope and exposure suit it, because those three things decide which foundation fits a cold-climate site best. Other options include frost-protected shallow foundations, post and pad, and piles. A long-standing national builder's guide says frost-protected shallow foundations suit slab homes on moderate to low slopes, but its design method doesn't apply on permafrost or where the yearly average temperature is below 32°F, so I check the lot before recommending any of them.

Testing shows what the slab will really sit on, and core drilling by machine is the most positive way to record it, because it logs the material continuously as the bit goes down. Boring costs more than other ways of checking the ground, but long-standing guidance points out that the cost is minor next to repairing a foundation that settles. If I think it belongs on your lot, I'll tell you at the estimate.

Inside Fairbanks city limits, the city's Building Department reviews and inspects every residential and commercial structure, with a zoning permit from the borough's planning department included. Inspections have to be called for before work is covered and requested 24 hours ahead, so we pull the permits that fall to us and book the inspections on our work. Outside city limits, we find out early which offices your lot goes through and tell you what, if anything, is yours to file and when.

Insulate under the slab, not just around its edges, because insulation around the perimeter alone isn't adequate for Alaska. When you compare bids, ask each contractor how they insulate beyond the perimeter, and you'll find ours spelled out on the estimate.

A slab foundation's price comes down to its size, how much digging and packed fill your ground needs, whether coring belongs in the plan and how the slab is insulated underneath. Lot access and the time of year can move it too, since a pour in cold weather takes more care. I write every estimate after seeing the lot, and it lists what's included so you can compare it with other bids.

Most of the time on a slab foundation goes into the steps before the pour, which are the ground check, the city's plan review covered in the steps above and waiting for the right temperature. After the pour, the slab has to cure, the slow hardening that gives concrete its strength, before anything is built on it, and cold weather slows that down. I'll walk you through the order of work when I see your lot.