8 critical home repairs you can't ignore

Basement cracks

You know you've got a problem when: You can see them and water is seeping through. In more serious situations, upstairs walls also crack and separate from windows, and doors won't close.

What causes it: Poor drainage that allows water to pool around the house, causing concrete walls to buckle and settle.

The worst that can happen: Water and mold will make your basement unusable and structural damage will occur in the rest of the house.

Fix it yourself? Not unless you're up for some serious digging. Repairs often require exterior basement walls to be excavated and water-proofed, and the yard to be regraded so that rain drains away from house.

Who should you call? A contractor that specializes in crumbling foundations. You need an expert opinion on what's causing the problem and how it should be fixed.