Balcony tile analysis

From: Chaiban Engineering Consultants, Inc. <jchaiban@aol.com>

To: jchaiban <jchaiban@aol.com>

Cc: surtreatflorida <surtreatflorida@yahoo.com>; giobello <giobello@yahoo.com>

Sent: Wed, Feb 20, 2013 8:20 pm

Subject: The Parliament Condominiums - WPB Contract and Balcony Tile issue chaiban engineering

Dear Mike / Giovani:

After our meeting this afternoon with Mr. Bijan Parssi, PE and members of the Board, I came to the realization 

as far as removing all the tiles from the balcony floor that the main reason as explained by the engineer was to

seal the concrete surface and then install new tiles on top of the water proofing membrane after removing all tiles

from all balconies and walkways whether damaged, lifted, cracked or not. The engineer's reasoning is what if there is a damage?

But now after  Surtreat's recommendation, the engineer and the Board agreed to perform an X Ray testing on 2 random areas of the balconies to see if the reinforcing steel is rusted, concrete damage or not.

But the main idea behind the balcony repair is to see if the reinforcing steel is rusted since water according to Mr. Bijan has been going

through the joints between the tiles and being trapped in the cavity between the tile and top of concrete surface thus causing damage

to the concrete and embedded reinforcing steel. But my question to the engineer is that shouldn't the Board and engineer conduct X Ray testing on the entire balconies in all the floor to see if the Reinforcing steel is rusted or damaged concrete exist? Also, if they remove the tile and apply moisture barrier  then install new tiles, but the reinforcing bars are rusted then what benefit is it to replace the tiles but leave the concrete in substandard condition not knowing if the reinforcing steel need to be repaired or not.

I think the engineer should have done his due diligence by recommending to X Ray the concrete at several random worst case areas to detect if Reinforcing steel or concrete structure has been compromised or not. Based on the results of the X Ray, then the engineer can make an educated recommendations regarding if the tiles need to be removed entirely or just in certain areas were damage of the slab have occurred.

Also, by removing all tiles, and application of water proofing then installing new tiles, would create a barrier for the moisture to be trapped inside the concrete balcony slab, and during hot season, when temperatures exceed 100 degrees F, water may evaporate and cause additional oxidation and damage to the reinforcing steel which may be oxidized any ways. Such a solution will prevent the concrete to breath and prevent trapped moisture to evaporate from within the concrete mass causing additional damage.

I agree with Mr. Parssi's explanation that water will penetrate the tiles and joints into voids between tiles and slab surface then seeping through the slab and accumulating in such voids.But Mr. Parssi did not explain what happens after water enters the air pockets inside the concrete slab and reinforcing steel. The water inside the slab will eventually drain to the bottom and slab edge due to the slope along the slab. Also, while the slab is saturated with moisture for extended periods of time, and years,the reinforcing steel will oxidize and rust. The rate of rust is directly proportional to the amount of water seeping through the slab as well as evaporation rate, flow rate and time. The report by Mr. Parssi indicated issues as far as dipping in tiles and 90% was along the edges of such slab. But Mr.Parssi did not know the extent of rust damage to the slab reinforcing steel or the extent of concrete delamination, or spalling as a result of the water intrusion. What he is recommending is the worst case scenario without taking due diligence steps and tests to confirm if such damage exists to the entire areas of the balconies and walkways. Therefore, pure speculation.But as an engineer one has the duty to suggest testing of an area by either X Ray of GPR to see if the slab section has been compromised,cracked, spalled as well as percent of reinforcing steel rust say 5 ft x 15 ft area. Also, removing tiles at a  test section at the worst observed tile damage location, and inspection of slab and thin set application.

Therefore, my recommendation is to perform X Ray testing at (2) random areas and removing the tiles at such areas of worst damage tiles then analyze test results to make an educated decision about the tile issue.    

Let me know what your thoughts are.

Regards;

Joseph Chaiban,PE.SI.MBA