BajaNomad

How to prevent salt from coming up through floor

bowser - 4-27-2017 at 08:36 AM

Does anyone out there have any tips on how to deal with salt coming up through a cement slab?

Our 12 year old house in BOLA was fine until Hurricane Odile. Since then we have have had more and more salt spots coming up through the floor.

We would like to not have to cover the floors since we put a lot of effort into staining and sealing the floors. They turned out great. And then the salt started coming up.

I remember reading on this forum a discussion about salt problems before we built 12 years ago, but can't find anything now.

Thanks for you ideas.

Paco Facullo - 4-27-2017 at 09:50 AM

http://whitepowdergoldnews.blogspot.com/2012/01/removing-pre...

What you have is efflorescence.
Probably due to an abundance of ground moistureafter the hurricane.

Everything you need to know,



[Edited on 4-27-2017 by Paco Facullo]

woody with a view - 4-27-2017 at 10:03 AM

read all the way to the bottom. this should help, unfortunately, there is no easy answer.

https://www.concretenetwork.com/doug_bannister/efflorescence...

chippy - 4-27-2017 at 01:05 PM

This might help.
http://www.fester.com.mx/es/noticias/salitre.html

chuckie - 4-27-2017 at 02:19 PM

that's a tough one..I fought the problem in the "old" part of my house in Mulege for years...Tried everything..Finally just put cheap rugs over it..Good luck

UnoMas - 4-27-2017 at 06:51 PM

If there is not a vapor barrier installed underneath the concrete slab the hydrostatic pressure will eventually pop the coating off the surface, be it urethane or epoxy and will have efflorescence problems. If you plan to put any type of coating on top of the concrete slab it is very important to have a moisture barrier underneath. Which by the way never happens unless requested.

bowser - 4-28-2017 at 08:55 AM

Thank you all. Good information. Just not what I wanted to hear.

Oh well, time to start looking for neat Mexican rugs.

surabi - 4-28-2017 at 07:53 PM

The floor got moisture under it because your foundations are not sealed and water got in. If you seal the outside foundations of your house, you will eliminate the source of the moisture, then you can wait for it to dry out well and treat the floor. A moisture barrier under the slab will not help if moisture can still get in under the floor from outside.

UnoMas - 4-29-2017 at 05:43 PM

surabi the moisture barrier wraps up the inside of the foundation wall.. No moisture coming from the foundation. Been the coating business since 1973 and have seen this problem 1000 times.
You put your vapor barrier down wrapping the foundation walls. Fill with compacted sand or compaction fill to the height of finished floor minus slab thickness then pour your slab. Once the moisture in the fill dry's out you can then stain, seal or paint.

surabi - 4-30-2017 at 08:02 PM

Quote: Originally posted by UnoMas  
surabi the moisture barrier wraps up the inside of the foundation wall.. No moisture coming from the foundation. Been the coating business since 1973 and have seen this problem 1000 times.
You put your vapor barrier down wrapping the foundation walls. Fill with compacted sand or compaction fill to the height of finished floor minus slab thickness then pour your slab. Once the moisture in the fill dry's out you can then stain, seal or paint.
I hear you Uno Mas. Just good luck finding anyone who knows how to do that properly in Mexico. A friend told her builder she wanted them to use a moisture barrier when they were building her house. They just wrapped it around all the rebar columns and cut it where they couldn't get it to lay flat, negating the whole point.