Cracked & heaved concrete

Hello Jon, Thank you for reaching out and providing such great detail about what's going on with your cottage garage! It sounds like a frustrating situation, but you are absolutely on the right track with your assessment. What you are experiencing is a classic case of frost heave. Because the garage lacks eavestroughs and downspouts, water is pooling near the foundation, seeping under the concrete slab, and freezing during the winter. When water freezes, it expands with massive force, pushing the concrete upward. The reason the slab hasn't settled back down is likely because the freeze-thaw cycle has shifted or washed away the soil underneath, leaving an uneven base and a void under that corner. Here is what we recommend for your next steps: Step 1: Address the Exterior Drainage (The Root Cause) You are 100% correct that this is the priority. Before any concrete repair is done, the water needs to be directed away from the garage. Installing eavestroughs, extending downspouts well away from the foundation, and ensuring the grading slopes away from the garage will stop this from happening again next winter. Step 2: Concrete Lifting (Saving the Slab) Your instinct to hire a concrete lifting service is spot on. Instead of tearing out the entire slab, methods like polyurethane foam injection (slabjacking) are highly effective here. The process involves drilling small holes in the concrete and injecting a high-density foam that expands, fills the voids left by the washed-out soil, and gently lifts the slab back to a level position. Step 3: Sealing the Crack Once the slab is stabilized and leveled, that 10' crack will need to be properly cleaned and sealed with a heavy-duty flexible polyurea or epoxy joint filler to prevent future water intrusion and protect the edges from crumbling.