Concrete expansion joint

[tflfb]

I have to replaced the concrete expansion joint a couple of times in my driveway where it meets the street.

Its made of a asphalt material, but it rots away over the years.

What is I remove the asphalt and instead of using that again, I use this spray foam they use to insulate, it comes in a spray can dries in a few mins.

Thanks Tom.

[mark Ransley]

the spray foam is not UV stable is soft and will deteriorate in a year of so, maybe use silicon caulk, or dont worry about it

[JTM]

The whole point of the expansion joint filler is to allow the concrete to expand and contract and to maintain a water resistant seal so the soil is protected from losing its bearing capacity. Putting a rigid piece of wood in place of the felt would either cause the wood to be crushed or the concrete to spall under the pressure. Stick with elastic material designed for the task.

Regards,

John

[Rich]

tflfb wrote, wondering if this is really what he meant?

The spray foam will fall apart over time once it's exposed to the sun. The UV rays break it down. It may last for a little while.

Good luck, Rich

[Ermalina]

I've had good results using backer rod and then sealing with [self-leveling] polyurethane caulk.

BTW, I believe the quality of the backer rod from building supply store is better than that sold in big box stores.

[George E. Cawthon]

You are wrong about the wood. Wood 2x4's are commonly used to fill expansion joints in new concrete driveways. The main problem is shrinkage and warpage of the wood. You don't see crushed wood and you don't see spalling caused by the pressure

[JTM]

Just because someone uses a hammer to drive a scew doesn't make a good practice. I see evidence of improper installations and poor workmanship all the time, but it doesn't matter how many times something is botched up or the number of people doing it--it is still shoddy practice. The fact that you don't see evidence of damage merely means that in the cases you have observed either the temperature range is not very extreme or the slab is free to move on the opposite end. And unless pressure treated wood is used the termites would make quick work of it, at least in my area they would.

Regards,

John

[George E. Cawthon]

You have a point, however the screw and hammer is not a good analogy to the wood expansion joint. In some part of the country wood expansion joints are common and standard practice, the screw and hammer is neither common nor a standard practice. Oh, I thing -30 to 110 is a pretty extreme range temperature range. And, termites are pretty uncommon here, although based on the termite/pest control companies a person moving to the area might be mislead. I have never lived in a house and seen only one house (and that may be suspect) that had some minor evidence of termites. Untreated cedar in full contact with the soil or buried commonly last 15-20 years here, and the untreated (probably fir) expansion joints of my driveway have lasted for 25 years and are still solid We just don't have termites.

OTOH, tar/asphalt as a major ingredient (in fiber board or other) is much more common for many types of expansion/contraction joints and is certainly superior to wood. A new common practice here for driveways is to pour large surfaces as a block and then cut them with diamond saws and caulk the saw cut.

All of this is probably minor compare to the common home construction practice here of not making any provision for curing concrete. I have regularly watched the construction practices in subdivisions here and have only occassionally seen any driveway covered with anything. Footings for crawl spaces are commonly poured, the concrete not covered, and the forms removed in 2 days. I have never seen the foundation walls covered and the forms are often removed in

24 hours, and never left more than 48 hours unless it is a holiday. Those foundations are poured in weather as hot as 100 degrees and as cold as 25 degrees with no provision for maintaining moisture or preventing freezing.

[Art Begun]

My parents had treated lumber expansion joints used 20 years ago and both the wood and slab are just fine (Long Island area).

opposite end. And