Sign: cracks in the concrete
Foundation crack repair
Concrete can crack as it shrinks during curing. A crack can also relate to movement, so record its shape, width and any changes. An inspection can establish which explanation fits your house.
Crack details to show the inspector
- One side of the crack sits higher than the other. Slide a coin across it to feel the step.
- It is wider than it was. Dated pencil marks across the crack will show this.
- It continues down the outside edge of the slab or up into the block wall.
- It lines up with cracked tile or a slope in the floor indoors.
- Sand, ants or damp come up through it.
Where foundations crack in Orlando houses
Slab on grade. The floor and its thickened edge are one pour of concrete resting on compacted sand. Cracks appear at inside corners, across garage floors and where the slab changes shape.
Stem wall. A short block or concrete wall stands on a footing, and the floor slab is poured inside it. Cracks show in the wall below floor level, often near corners.
Older houses on piers have no slab to crack. Their signs are in the framing, covered on the crawl space page.
Sealing a crack and stabilising a foundation are different jobs
| Sealing the crack | Stabilising the foundation | |
|---|---|---|
| What it does | Closes the crack against water, soil and insects | Stops the two sides of the crack from moving further |
| Typical materials | Epoxy to bond the concrete, or flexible polyurethane to seal it | Piers under the footing, or grout or foam under the slab |
| Suits | A crack that is no longer moving | A crack that is growing, or one with a step across it |
| Order of work | Can be the whole job | Done first; the crack is usually sealed afterward |
Sealant in a crack that is still moving does not hold. Before pricing either job, a company should be able to say why it believes the crack is stable or active.
What a company checks
Expect measurements of the width and of any step between the two sides, a look at where the crack starts and ends, and floor heights on both sides of it. Carpet or vinyl may need lifting at an edge. If the crack is near plumbing, a pressure test of the pipes may be suggested, since a leak under a slab can carry sand away.
Crack repair questions
Does a hairline crack in my garage floor need repair?
A hairline crack with both sides level, which has not changed, is usually shrinkage. Many owners leave it or seal it to keep water out. Pencil a mark at each end with the date so you can tell if it grows.
Will crack repair need a permit?
Structural repair to a house needs a building permit in Florida, and the contractor normally applies for it. Whether sealing alone counts is a question for your building department. The permits guide lists who to ask.
Ready to have the house looked at?
Only someone standing at the house can tell you what is going on under it. Call, explain what you have noticed, and ask for an inspection.
Describe the problem, book an inspection
Say where the cracks or dips are and when you first saw them. The independent local foundation repair company you reach can set a time to look at the house.
Call (407) 598-8829The call may be recorded. See how referrals are paid for and what happens to your details.