Crystalline VS. Polyurethane Waterproofing

[Alan CA]

Crystalline is so known for doing a great job waterproofing pipes, tanks and swimming pool walls if you don't want to drain the pool. However, it can't take much movement since it's so rigid.
We know that Polyurethane injection doesn't have this problem and on the other hand, it can penetrate deep into cracks. What's the downside of Polyurethane injection that make people use crystalline waterproofing for the same scope of work?

 

[dik]

As long as the crack is not active and not too wide, crystalline material works well.

Dik

 

[Alan CA]

So, when is Polyurethane injection preferable?

 

[dik]

Definitely if you have a 'wider' crack that is moving. It will move with the crack, bond to the surfaces of the crack and afford movement.

Dik

 

[Alan CA]

Thank you very much dik. I appreciate it

 

[dik]

Glad to help... That's what this site is for...

Dik

 

[Ron]

To add to dik's excellent (as always!) comments, crystalline treatments are essentially pore fillers that fill and seal natural pores in concrete. Polyurethane and other types of injectable sealants are not pore fillers....they are crack fillers. They usually allow some movement within the crack through their extensibility or flexibility. Crystalline pore fillers have little or no extensibility and flexibility...that's not their purpose. You can used both, just use the injectable sealants first, then the pore filler.

 

[dik]

Ron:
Now my hardhat doesn't fit...

Dik

 

[Alan CA]

Thank you Ron for the useful information. Glad to be in such a nice environment at this Forums

 

[Ron]

dik...you and I are from the same era.....our heads are hard enough not to need hardhats!

 

[epoxybot]

In route to making a selection as to the best material for sealing a crack, it should be understood that while you can subsequently inject urethane into cracks that were previously repaired/injected with epoxy; cracks injected with urethane cannot be subsequently injected with epoxy.

 

[dik]

epoxybot touches on a couple of issues... prior to undertaking a repair, the cause of the cracking should be determined... in addition to epoxies not being used with polyurethanes... most polyurethanes can bond to other polyurethanes chemically... many epoxies cannot accept an epoxy bonding...

Dik