4 month old house, cracked garage floors

[photon]

My garage floors are showing quite a few cracks (6-7 ones all over), a couple that you can actually put a fingernail or dime into.. Is that normal to have cracks that fast?

[MacDougalbry]

I think they have to be at least the width of a quarter before a builder is required to fix them under the ANHWP, although I believe our builder will not fix anything under 1/4", I think. Shrinkage cracks are very normal. Settlement cracks (is there a change in elevation between the two areas separated by the crack?) would be more concerning. Wait until near the end of your warranty before having them repaired.

[tussery]

Depends on the type of soil the home is built on. If the soil consists of mostly clay the house will settle quicker when the soil is wet.

Clay can also be troublesome. The strength of clay soils varies inversely with changes in moisture content: the greater the moisture, the weaker the soil. If clay materials underlie your site, the site plan must provide for positive drainage that will direct surface water away from the structure and paved areas; otherwise, water may penetrate and weaken the supporting soil. This is, in fact, a common cause of post-construction settlement problems. If site constraints make it impossible to direct runoff away from the driveway, you should plan to provide lateral drains alongside the driveway to prevent water from accumulating beneath the pavement. Foundation drains must also be carefully designed to carry groundwater well away from the structure. These measures aren't cheap, but they cost less than repairs, ill will and neighborhood gossip.

[Eddie Bronze]

And if it is a settling problem that has shown up this quickly, you should definitely be taking up with the builder. The excavation process on a lot of these new places being built is certainly not being done properly. You put a load of fill in, whatever it is, and it's to be tamped. Each 6 inch (approx) layer is to be tamped down and compacted. You're also supposed to "wet it down" as well. It's not being done properly in a lot of the homes, basement or garage, and home owners should be getting after the builders early on to make sure the process is completed in the way it is supposed to be.

Anyone who has experience with this will tell you the amount of settling in ground can be pronounced and it surprises alot of people. It can and will sink upwards of a couple feet if the process isn't done properly to begin with.

[photon]

Hm, I was pretty on top of most aspects of the building process, but didn't know about the tamping, but that makes sense.

I didn't look really close, but I don't think there was a change in elevation on either side of the crack which hopefully means they're just shrinkage cracks.

We've got a list of defincies to send in anyway, I'll just add this to it and we'll see what they say.