Concrete Repair in Derry, NH
A low slab, a broken edge, and a moving crack are three different problems. Here is how to tell them apart before you spend money.
Which route fits the concrete?
Keep and repair
Sound surrounding concrete with a limited damaged edge may support a focused repair.
Lift an intact panel
A sound but low slab belongs in a concrete-leveling assessment.
Replace or inspect the house
Broken pieces may need a new pour. Movement tied to the building needs a structural check.
Reading the slab before pricing the slab
Start with what the concrete is doing, not what it looks like from the street. A front walkway or a patio by the back door can look uneven from a distance and still be sound up close. Check for hollow sound underfoot, a joint that has lifted, a crack with offset edges, or a surface that is scaling and flaking. A sound but low panel moves as one piece. A broken edge or a spalled face is a surface repair. A slab that is cracked through, heaved, or moving with a wall is a different conversation. Walk the whole route from the driveway to the door. One lifted joint may matter more than a broad area that only looks uneven from a distance.
What can stay, and what earns a repair
Not every defect needs work. Hairline cracks that have not moved, minor surface scaling, and a single low panel with no broken edges can often stay on a watch list. Repair earns its place when the defect changes how you use the slab or how water moves across it. A trip edge at a walkway, a broken corner at a step, or a crack that has widened since last season are practical reasons to act. A slab that is still flat and tight but stained is a cleaning question. The honest answer is sometimes that you do not need a repair this year. We would rather tell you that than sell a scope the concrete does not need.
Matching the method to the defect
Method follows diagnosis. A sound panel that sits low is a candidate for leveling, where the slab is lifted back toward grade rather than replaced. A broken edge or a spalled surface is a candidate for horizontal repair preparation, which means cleaning out the loose material and rebuilding the section. A slab that is cracked through, heaved, or tied to a moving wall is a candidate for removal and re-pour. ACI RAP-7 discusses horizontal concrete repair preparation, ACI RAP-11 discusses slabjacking assessment, and ACI RAP-1 discusses structural concrete cracks. We use them to frame the decision, then scope the work to your actual slab.
ACI's horizontal repair guide is general technical guidance, not a specification for this house.
Derry scope and local context
Derry Public Works is the town department responsible for roads and related public infrastructure. That matters when a raised edge sits on a town walk or roadway edge. We should not treat that as a private patio quote. The homeowner can confirm public-side responsibility with Derry while we scope the concrete on the property. Keeping that line clear stops a municipal flatwork question from being folded into a private repair estimate.
Read the Derry source. We check the approval path against the proposed scope.
Where a repair stops being a repair
Some conditions are outside a surface repair. If a crack is tied to a moving foundation wall, fixing the slab alone will not hold. If the subbase has settled deeply, a thin patch will crack again. If a slab is broken into several pieces with offset edges, patching is cosmetic. Those are removal and re-pour conversations, and sometimes they are foundation conversations. A structural crack does not automatically mean piers, and a low slab does not automatically mean leveling is cheaper. We flag what we cannot fix from the surface and tell you what trade or specialist should look at it. That limit is part of the estimate, not a surprise after the work starts.
What homeowners say about working with 603
Site conditions that change the scope
Access, drainage, and what sits on the slab change the scope. A patio by the back door with a fence and a downspout in the way is a different job than an open front walkway. Slope matters: a slab that drains toward the house is a water problem before it is a concrete problem. Tree roots, a settled backfill zone, and a driveway that ties into a garage floor all affect how a repair is staged. We look at how water leaves the area and what the slab is attached to. If the raised edge is on a town walk or roadway edge, that is a public-side question, and we keep it out of a private flatwork quote.
Estimate, measurement, and what gets written down
A useful estimate starts with measurements, not adjectives. We measure the slab, note the joint layout, and record the defect in plain terms: low panel, broken edge, spalled surface, or cracked through. The written scope says what will be repaired, what will be left alone, and what is excluded. If a slab is a candidate for leveling, the estimate says so. If it is a candidate for removal and re-pour, the estimate says that too. We do not quote a method we have not confirmed on site. NRMCA CIP6 discusses planned slab joints, which is a reminder that joint layout is part of the plan, not an afterthought. You get a scope you can compare.
When the right answer is no work or smaller work
The cheapest repair is the one you do not need. If a slab is sound, flat enough, and not moving, we will say so and suggest watching it. If one joint is lifted and the rest of the route is fine, a small targeted repair may be the whole job. If a crack is stable and not a trip edge, monitoring is a real option. We would rather hand you a smaller scope than a full replacement you did not need. That decision is yours, and it is easier to make when the diagnosis is written down. Ask what can stay before you ask what it costs to replace.
Related repairs if this is a different problem
One question for the inspection
Do I need to replace my whole patio, or can one low panel be leveled?
It depends on the panel, not the patio. If the slab is sound, sits low as one piece, and has no broken edges, leveling is a candidate. If it is cracked through, heaved, or tied to a moving wall, removal and re-pour is the more honest scope. We walk the route, check the joints, and tell you which one you have. Sometimes the answer is that one joint matters and the rest can stay.
Get a straight answer in Derry
Show us the concrete and we will tell you what is worth fixing, what can stay, and what still needs checking.
