The choice comes down to one question: is the ground under the slab stable? If it is, repairs last. If frost or water keeps moving the slab, repairs buy a season or two. The dollar figures in the questions below are the customers' own numbers. They are not our prices.
Is it cheaper to repair or replace concrete?
It is cheaper to repair today, nearly every time. Whether it is cheaper over ten years depends on why the slab failed. Sealing cracks and lifting one panel on stable ground is good value. Repairing a slab that heaves every winter is paying for the same problem again and again.
My driveway is 20 years old and one section sank by the garage. I was quoted $9,000 to replace all of it. Do I need to?
Probably not all of it. One sunken section by the garage is usually settled backfill along the foundation, which is a local problem. If the other panels are level and sound, that one section can be lifted or cut out and poured again for a fraction of $9,000. Replacing everything makes sense only if the rest is heaving, scaling badly or broken up. Ask the contractor to show you what is wrong with the other panels.
Repair for $7,000 or replace for $14,000 if I plan to sell in two or three years?
Replacement costs $7,000 more, and you would use it for two or three winters. If the repair makes the slab safe and tidy and the ground is stable, the repair is the sensible spend. The catch is that $7,000 is a lot for a repair. Check what it covers. If it includes lifting and resurfacing on ground that heaves, it may look rough again by the time you list the house, and then replacement was the better buy.
I am selling the house and the driveway has a few long cracks. Repair, replace or leave it?
If the cracks are tight and level, clean and seal them and leave the rest. Buyers in Anchorage expect some cracking in older concrete. What draws a low offer is a trip lip, a sunken apron or water running toward the garage. Fix those. Full replacement before a sale seldom returns its cost.
One contractor says remove it and another says pour a new layer over it. Who is right?
Ask each what happens at the first winter. A new layer over an old slab copies its cracks and moves with it. If the old slab is flat, solid and not heaving, a bonded overlay can work. If it has shifted or broken, the contractor who says remove it is right. In frost country the base decides the result, and you can only fix the base with the old slab out.
My driveway is 30 years old with cracks from tree roots and I am on a tight budget. Can I just grind and patch?
Yes, on a tight budget that is a fair plan for a few years. Grind the raised edges so nobody trips, seal the cracks so less water gets in, and put money aside. Be clear about what it is: the roots and the frost are still there, and the lips will return. When you do replace, do the worst panels first.
I have many small cracks but no sinking. Is sealing or resurfacing enough?
Sealing or resurfacing is enough when the cracks are hairline, the slab is level and the surface is still hard. Seal it to keep water out. Resurface only if you want a new look. If the fine cracks form a map pattern and the surface is dusty or flaking, the top layer is weak and a coating may not bond for long.
My old patio has cracks and flaking. Can it be resurfaced, and how long will it last?
A patio can be resurfaced if the slab under the flaking is solid and it stays put through the winter. A resurfacing done in warm weather on a sound slab, and then kept sealed, can last for years. Nobody can promise a number in this climate. On a patio that holds water or lifts with frost, expect a shorter life.
What do you check before you recommend one or the other?
- Whether the two sides of each crack are level.
- Whether the slab rocks or sounds hollow.
- What soil is under the edge: gravel, silt or peat.
- Where meltwater and roof water go.
- Whether the slab is higher in March than in July.
- The thickness and the condition of the surface.
The only real price is one written after we have seen the site. Call (907) 331-4363 or text us a photo of the area to set up a free on-site estimate.