Selecting the right expansion board for an expansion joint 1

[GeotechRic]

Here is the situation, due to the project requirements I need an expansion board that is flexible and excellent as a water seal. The board would be used for an expansion joint between a concrete wall and a wall cap in order to prevent water from infiltrating behind the wall and freezing and thereby creating problems. Basically we need something better than typical wood/plastic expansion boards. Any suggestions?

Also what would be the procedure to install these? Would a sealant be also needed on top of the board to ensure a better seal?

 

[GeoPaveTraffic]

It sounds like you need a prefabricated issolation joint. The ones I have seen are compression joints and are installed by compressing the joint and placing it between the two different structures. They come in different sizes and have different amounts of allowable expasion and should last for several years.

The only place I have seen these used is in buildings, generally between an occupied building and a parking garage.

 

[JedClampett]

I would recommend that if you really want a good seal that you install a waterstop. Greenstreak (

http://www.greenstreak.com/)

makes a wide variety. Anything you stuff into a joint like that will deteriorate and eventually lose its seal. Or you can use a manufactured expansion joint by someone like Migua (

http://www.emseal).

Note that any of these installations are detail oriented and not that easy to do right.

 

[JedClampett]

Actually, the Migua website is

http://www.emseal.com/.

 

[Ron]

Assuming you are placing concrete against an existing building, the waterstop idea (though good) might not be plausible. There are several expanding foam joint seals available for such applications. Remember, you only need isolation, not true expansion joint. Concrete rarely expands to any point larger than when it was placed.

As a simple alternative, put in the typical fiberboard (asphalt impregnated jute) and after concrete placement, put a backer rod and sealant in the upper inch of the joint after removing part of the fiberboard.

 

[unclesyd]

Here is one type waterproof joint available.

http://www.plakabeton.be/jointsuk.htm

Serendipity, just this minute ran across this site while looking for a mechanical coupler. They have a lot doodads for the concrete set.