waterproofing 6

[rayadh]

Hello. My actual area of expertise is in electro-ceramic science. So, this question may show my lack of experience with concrete. However; I am interested if there are additives to concrete that impart some degree of waterproofing. I have done excavation work on a relative's house in a damp geographic area and essentially tarred the outside down to a one foot undercut beneath the cellar. It worked -- no more water. So, I know various coatings work. Are there additives that can be mixed into concrete prior to set that acheive the same or nearly the same effect? It seems hard to believe they would work without interferring with the concrete setting, but I have heard there are such additives.
Thanks for all who are patient enough to respond.

 

[ishvaaag]

Yes there are. THere are mass additives, and there are very "pastic" impermeable mortars. Firms like Sika may give you indication of what specific product will fit your application.

I have had trench walls besides a small water channel constructed that allowed excavation this way without any problem coming from such flow. The foundation proper additional wall made of the final thing a very thick arrangement, but in any case worked.

 

[Ron]

Rayadh...while there are additives to concrete that tend to "repel" moisture, none are as effective as the waterproofing you described for your basement application. The most appropriate concrete waterproofing is still the use of a fabric reinforced asphaltic or coal tar coating.

 

[phuduhudu]

I agree with Ron. The problem with additives to concrete is that they can repel water but as soon as you get small cracks water gets through these. Hence people mostly go for a separate waterproofing membrane. However, concrete can also be designed to be waterproof by minimising crack widths and using waterbars at construction joints. This can mean using quite a lot of reinforcement though and you have to pay careful attention to the spacing and covers. Carl Bauer

http://www.bauerconsultbotswana.com

 

[StructuralDzine]

Xypex is an additive that appears to be quite effective. It causes the growth of insoluble crystals in cracks blocking water flow. It can be applied to the surface or added to the mix.

Chris Rohde
Editor, Structural D-zine

http://www.topica.com/lists/Structuraldzine

 

[rayadh]

Thanks to all for their input. This is great information. I am glad I joined this list! Thanks again.

 

[absoluto]

I am confused after discussing with an engineer from a waterproofing specialist. He said that additive added to concrete or screeding for waterproofing purpose could not be waterproof but just to decrease the porosity of concrete and screeding. Therefore, waterproofing screeding is NOT waterproof. In other words, only waterproofing lying can be treated as fully waterproof treatment. Would anyone introduce some link or technical paper for this issue.

Thank you in advance.