Concrete Questions

[JEuriech]

Concrete Questions

If there was no expansion joint between the back of a house and a concrete patio slab, would this be called out as a defect? (only one side/face of the slab touching the house)

On a new house, if three sides of the patio slab was touching the house with no expansion joint, I assume this would be a defect because there is no room for expansion. (damage may occur) If it was a five year old house with no signs of cracking, would you still call it out as a defect?

In the summertime, how much will concrete expand, say for a 20' section of driveway? Are we talking like a 1/4" or something a lot more?

Thanks

Jeff Euriech

Peoria Arizona

[Scottpat]

Both were most likely poured at the same time. You will see this done with garages, the front porch and patios. It is a time saver and that is about all.

Concrete is at it's largest point when it is first poured. It shrinks as it cures. As for expanding when it is hot, I don't know how much but it would be a very small amount.

[ozofprev]

A 10m length undergoing a 50 degree centigrade temperature increase expands about 5mm.

http://www.cement.ca/cement.nsf/0/74270 ... ent&Click=

[chrisprickett]

Jeff,

It's commonly done out here when there's a monolithic pour. You'll likley see some hairline cracking, but it's not s a structural isse.