Tile Pool Deck grout lines

firstbase

Well-known member
Feb 6, 2013
104
Jupiter, Florida
I have a Travertine tile pool deck with very fine grout lines or openings between each tile. No grout or sand just a crack between tiles. I believe they were originally installed edge to edge. Some have shifted with time and there are some that have a little movement when we walk on them. I seem to remember some advice in here that said to mix sand and a small amount of Portland cement and then sweep it into the cracks. Water lightly and..there you go...cracks filled with something stable. Did I actually read that advice or did I dream it?!?! Is that the proper way to fill the lines and provide a little more stability? Thanks in advance for any and all comments!
 

zea3

Mod Squad
TFP Expert
LifeTime Supporter
Jul 10, 2009
12,643
Houston, Texas
That is standard for paver installation. Either someone skipped a step or too much power washing stripped it all away.
 

firstbase

Well-known member
Feb 6, 2013
104
Jupiter, Florida
That is standard for paver installation. Either someone skipped a step or too much power washing stripped it all away.
Thanks. It may have been there years ago but sure don't see any now! My only concern about this, not sure if it is valid, is the deck's ability to shed water. It would seem that filling up the cracks with a mix that is waterproof may cause an issue?

Is there a particular type of cement/Portland? Maybe a premixed product for this use? If it is plain old Portland and sand, what is the correct ratio? Thanks again.
 

Dirk

Gold Supporter
TFP Guide
Nov 12, 2017
6,896
Central California
No expert on the subject here, but I think you want the deck to be water proof (as much as possible). Water should sheet off the deck, away from the pool, into a proper drainage system, and divert where you want it to go (as in, away from the deck). Not leech through the deck and undermine the dirt underneath. I'm lifting this theory from what I know about my deck's expansion joint. That joint needs to be filled and water tight so that water from rain or the pool doesn't seep down between pool and dirt and deck, causing separation. I think the dryer all that dirt stays, the more stable it will be.
 

spd500

Well-known member
Jul 20, 2020
434
Houston, TX
Dirk is correct. If the water drains through the pavers it will eventually start to wash away the sand under the pavers and that is why you start to see loose pavers and low spots
 

firstbase

Well-known member
Feb 6, 2013
104
Jupiter, Florida
Thanks for all the info. Makes sense to keep water from seeping through. Not sure if it is obvious but I'm not a pool builder nor do I play one on TV. :) And the polymeric sand was what I was looking for! I believe this is as simple as sweeping it into the cracks to fill them, clean up the top of the tiles and then lightly moisten with a mist of water, correct?
 

firstbase

Well-known member
Feb 6, 2013
104
Jupiter, Florida
One issue I note, the polymeric sand directions say the minimum width of the joint should be 1/4". Mine are nowhere near that. More like 1/16"- 1/32". Looking closely I see that sand is in place in many areas but washed out in some. Some pavers are so butt-jointed so tight I don't think sand could get down between them.
 

JJ_Tex

Bronze Supporter
Jul 17, 2019
1,646
Prosper, TX (DFW)
My joints are nowhere near 1/4 either. When I was watching my installers last year, it was a pretty painstaking process to install the sand. There was one poor soul on his hands and knees applying the sand. He had a small wisk broom and would work with handfulls of sand at a time. I bet it took him almost a full day to install. I was expecting a much quicker process with a push broom, but he seemed to know what he was doing, so I didnt complain :)
 

firstbase

Well-known member
Feb 6, 2013
104
Jupiter, Florida
Yes, a push broom was my first thought as well but now that I am getting closer to doing it and really thinking about the process...I can see a lot of time in my knee pads. I can also see the need to have a thin chisel or something to spread the grout line, tightening it up on the other side to get sand in the line. One last thing, I think that a good pressure washing to clean everything up first is needed as well. I see where someone did this in the past in some places (new to us house and pool).
 

JJ_Tex

Bronze Supporter
Jul 17, 2019
1,646
Prosper, TX (DFW)
I went back to my pictures to see if I could find a pic of them installing the sand and could not find anything. Here is a during and after pic, but thats the best I have:

Patio Day 3 - 1.jpg
IMG_6127.jpg